Anything that can increase an individual’s chance of developing a disease is a risk factor. Some examples of risk factors for cancer: age, family history for a particular type of cancer, tobacco use, exposure to radiation or certain chemicals, certain genetic alterations, infection with certain viruses or bacteria.
Risk factors for cancer can be divided into 4 categories:
1. Behavioral risk factors are those that can be modified or treated by individual or physician. This includes: nutrition, physical activity, tobacco use, alcohol consumption, sexual activity and adherence to screening guidelines among other individuals.
2. Risk factors found in environmental compartments things around you, including where you work or live, for example smoking and chemicals used are environmental risk factors that can cause cancer.
3. Biological risk factors are based on the individual’s physical characteristics such as the gender, race, age or appearance of the skin (skin).
4. Genetic risk factors you inherit genes from parents contribute to genetic risk factors. There hereditary risk factors that may increase the risk of multiple cancers and multiple generations of a family MEBRA with similar cancers.
Risk factors for cancer are both internal and external and some are behavioral risk factors.
Risk factors for cancer include:
1. Older age
3. Sun exposure
4. Ionizing radiation
5. Certain chemicals and other substances
6. Some viruses is bacteria
8. Family history of cancer
10. Bad diet, physical inactivity and overweight
Behavioral risk factors are:
1. The use of tobacco
2. Exposure to sun
4. Bad diet, physical inactivity and overweight
Many of these risk factors can be avoided, others like for example family history cannot be avoided. Individuals can protect themselves by avoiding known risk factors. If a person is deemed to have a risk factor for cancer it is best to discuss this issue with an oncologist and to establish a scheme of investigations. Many factors may act together to cause normal cells to transform into cancer cells.
When considering the impact of risk factors in determining a cancer we must have in mind the following:
1. Not every risk factor causes cancer.
2. Cancer is not caused by injury, for example a swelling or bruising.
3. Cancer is not contagious. Although infection with certain viruses or bacteria can increase the risk of certain cancers, there is no transfer of cancer from one person to another.
4. The coexistence of several risk factors does not mean that the same person will get cancer. Most people who have risk factors for cancer will never develop cancer not.
5. Some people are more susceptible than others to the known risk factors.
At least two thirds of cancers are caused by environmental factors. Many of these cancers are linked to lifestyle that can be modified such as cigarette smoking, excessive alcohol consumption, unhealthy diet, physical inactivity, overweight or obesity. For example 1/3 of all cancer deaths can be prevented by eliminating tobacco. After tobacco overweight or obesity appear to be preventable causes of cancer most important. In addition to lifestyle, home service and workplace precautions must be taken to reduce exposure to harmful substances.
A. Older age is the most important risk factor for cancer. Most cancers occur in people older than 60 years. But cancer can occur at any age including children.
B. Tobacco. Exposure to tobacco carcinogens justify 1/3 of all cancer deaths annually in the United States. Tobacco in any form (cigarette, pipe, chewing) was associated with lung cancer, oral cavity, urinary bladder, colon, kidney, ENT, esophagus, stomach, cervix, liver, pancreas, leukemia. Tobacco contains more than 100 cancer-causing substances. Smoking is the cause of 85% -90% of lung cancers. The risk is 30 times higher in smokers as nonsmokers. The risk decreases after smoking cessation, but this becomes significant after 5 years of stopping smoking. Smoking is the leading cause of lung cancer known. There is a clear dose-response relationship between lung cancer risk and number of cigarettes smoked / day, inhalations degree and the age at which began to smoke. A lifetime smoker has a risk of lung cancer 20-30 times higher than a nonsmoker. Smoking increases the risk of lung cancer histological – all forms, although the relative risk is higher for squamous cell carcinoma and small cell carcinoma than for adenocarcinoma. Adenocarcinoma was always more common in women than in men, both in smokers as well as nonsmokers. Proof that the risk of lung cancer is higher in women than in men at similar levels of exposure to smoking was diminished by recent studies in Europe, which concluded that the risk is similar in the two sexes.
C. Exposure to ultraviolet sun rays coming from the sun, sunlamps, tanning beds, artificial cause skin aging and DNA damage leading to melanoma and other skin cancers. Skin cancer incidence is increasing rapidly. Reduce exposure to ultraviolet radiation decreases the incidence of skin cancer. Ultraviolet radiation with the highest intensity is between 11 – 15 hours. Sun exposure can be reduced by changing the activities that take place outside the closed cabins to reduce exposure to ultraviolet radiation in particular between 11 and 15, wearing protective clothing, use adequate amounts of protective substances. People who tan poorly or have burns after sun exposure are particularly susceptible to skin cancers. These people can benefit in particular protective measures.
D. Ionizing radiation Ionizing radiation is invisible, has high frequency which can damage DNA or genes. Ionizing radiation sourced in the cosmic radioactive fallout, accidental gas radon and X-rays from other sources.
We are all exposed to very low doses of ionizing radiation coming from cosmic rays (rays entering the Earth’s atmosphere from outer space). The radiation from this source can justify about 1% of the total risk for cancer.
Some homes have elevated radon, a radioactive gas that occurs naturally in soil most in a low level. Radon is produced by the degradation of uranium that naturally releases tiny amounts of ionizing radiation. High levels of radon found in some rocky soils. Radon effect was seen initially in the increased number of lung cancers around uranium mines. Radon gas enters the house through cracks in the ground or cracks in the foundation. It is estimated that about 20,000 lung cancer deaths are caused by exposure to radon in homes. Another source of ionizing radiation are the radioactive substances released by radioactive fallout or atomic bombs.
Ionizing radiation dose received from atomic bomb survivors in Japan have prompted an increased risk of leukemia, cancer of the breast, thyroid, stomach, lung. People exposed to radioactive iodine some form called Iodine I 131 or 131 that collects in the thyroid, may have an increased risk of thyroid cancer.
Some people are exposed to ionizing radiation exposure during certain medical procedures. Some people who receive radiation therapy for cancer or other diseases may have an increased risk of cancer. For example people treated with radiotherapy for acne and childhood, or other diseases with high risk for thyroid cancer and cancers in ENT area.
X-rays used for diagnosis of disease is another form of ionizing radiation. The radiation dose is very small in this situation and most long-term studies did not show an increased risk for cancer.. One exception exists, namely children whose mothers were irradiated during pregnancy. These children are at increased risk for other cancers and leukemias. Women who were irradiated chest with low dose weekly in monitoring for diagnosis of pulmonary tuberculosis are at increased risk for breast cancer.
E. Certain chemicals
People who have certain activities (painters, builders, workers in the chemical industry) have an increased risk of cancer. Many studies have shown that exposure to asbestos, benzene, benzidine, cadmium, nikel, or vinilcloride in the workplace can cause cancer. Although the risk is higher for workers with many years of exposure it seems natural to be careful when pesticide specialty they are dealing machine oil, solvents and other chemicals.
1. Pesticides About 20 of the 900 registered in the US are carcinogenic substances. These are: ethylene oxide, amitrole, some chlorophenoxy herbicides, DDT, dimethylhydrazine, hexachlorobenzene, hexamethylphosphoramide, chlordecone, lead acetate, lindane, mirex, nitrofen, and toxaphen. People who wielded such products have an increased risk for leukemia and lymphoma, cancers of the tongue, stomach, lung, brain, prostate, melanoma and other skin cancers. All these pesticides are listed as possible risk factors but are not ascertainable.
2. Benzene is used as a solvent in chemical and drugs and as a component of gasoline. Causes leukemia in humans. Inhaling contaminated air is the main method of exposure. Because benzene is present in gasoline, air contamination occurs around gas stations in congested areas by car exhaust gases. It is also present in cigarette smoke. It has been estimated that half of the exposure to benzene in the US is from cigarette smoking. Nearly half of the US population is exposed to benzene from industrial sources and almost every person in benzene in gasoline. Since 1997 prohibited its use as an ingredient in pesticides.
3. Fiber, fine particles and dust
Asbestos fibers and all commercial forms of asbestos are carcinogenic in humans. It is involved in the development or peritoneal mesothelioma and lung cancer. Exposure to asbestos justifies the highest percentage of occupational cancer, with the highest risk among workers who smoke. Asbestos fibers are released into the environment by using and damaging more than 5,000 asbestos-based products, including roofing materials, electrical and thermal, cement pipes and panels, floors, fittings, plastic, textile and paper products. Workers with asbestos insulation, brake repair and maintenance, building demolitions are exposed to high levels of asbestos.
Ceramic fibers are used as insulation materials and asbestos replacement. Since they are resistant to high temperatures used for ceramic fiber, wallpaper ovens .These can cause lung cancer in experiments on animals.
Silica dust is associated with an increased risk of lung cancer and is found for example in the industry as coal mines, mills, processing and exploration of granite,
Stone processing, operations using sand.
Wood dust is associated with cancers of the nasal cavity and sinuses and is a known carcinogen unprotected workers in the furniture industry.
4. Dioxins are unwanted bio-products of chemical processes and hydrocarbon containing chlorine. There are at least 100 types of dioxin. They are not produced intentionally industry. They are produced by bleaching paper and pulp, toxic waste incineration, municipal or hospitals. They also are found in some insecticides, herbicides and wood preservatives. Dioxins accumulate in fat and slow decay. A particular dioxin which seems to be carcinogenic in humans is TCDD (2,3,7,8-tetrachlorodibenzo-pdioxin). TCDD is highly carcinogenic in animals and people very exposed. The general population is exposed to low levels of TCDD mainly from milk products, fish, meat including poultry.
5. Aromatic hydrocarbons (PAH)
Several studies have shown an increased incidence of cancer of the lung, skin and urinary tract in people exposed to a mixture of aromatic hydrocarbons (PAH). The main source of PAH is the burning of carbon-containing compounds. PAH occurs in the air by burning wood and fuel in homes. They are also contained in gasoline and diesel exhaust gases, soot, smoke from furnaces, smoke cigarettes and cigarette, food cooked on charcoal. They are bio-products of fire, waste incinerators, coal gasification, coal furnace emissions. Foods that contain small amounts of PAH include food smoked, grilled or coal, coffee and fried sausages.
Arsenic compounds of arsenic are associated with many forms of cancers of the skin, lung, bladder, kidney and liver especially when high levels are consumed in drinking water. In addition to arsenic occupational exposure to inhaling them especially in mining, copper smelting was associated with an increased risk of lung cancer. Arsenic is also used in wood preservatives, glass, herbicides, insecticides and pesticides and is an environmental contaminant air, food and water.
Beryllium compounds are known to cause lung cancer. These compounds are used as metals for the aerospace and defense industry; electrical components, X-ray tubes, nuclear, aircraft braking mechanism, additives to fuel the rocket, lightweight aircraft construction, manufacture ceramics; as additives to glass and plastic, dental applications and golf club. Industry uses beryllium optical fibers and the cellular communication system. Besides these industries beryllium exposure occurs mainly by burning ovens and mineral oils.
The population may be exposed to small amounts of beryllium by breathing air and eating food contaminated with beryllium. Small amounts of beryllium in drinking water, food and tobacco were reported.
Cadmium and cadmium compounds is associated with an increased risk of lung cancer.
Workers with high exposures to cadmium are those involved in removing zinc and lead ores, production of cadmium dust, cadmium coated steel used in welding alloys containing cadmium activities. Cadmium is mainly used for wrapping the metal to prevent corrosion. Other uses are in the manufacture of plastic and synthetic products of batteries, as stabilizers for polyvinylchloride and fungicides. Industrial processes involved in manufacturing this product eliminate cadmium in the air at the water surface to the bottom, on the soil surface where it can be taken up by plants or the ground water and subsequently transferred to the animals. Surface contaminated soil that allows taking in tobacco plants can be indirectly responsible for most human non-occupational exposure to cadmium. Food is the main source of human exposure to cadmium for non-smokers.
Chromium compounds are known to cause lung cancer. The steel industry is a major consumer of chromium. It is used to protect against corrosion of metal accessories, including auto parts, as for electroplating, metal layering over another. Chromium Electroplating converts crom6 carcinogenic to a non-carcinogen form of chromium. This means that workers who wielded crom6 are at a higher risk than the general population. Other uses include high-temperature nuclear research and industry and textiles skin coloring pigments floors covering products, paper, cement, asphalt wrapping, for creating color emerald colored bottles. Chromium is widely distributed in air, water, soil and food and probably the entire population is exposed to some of these compounds. The highest exposure occurs in activities related to the production of stainless steel, welding, chrome and skin coloration. Typically in most fresh food are low levels of chromium.
Lead acetate and phosphate appear to be carcinogenic in humans based on the fact that produce renal and brain cancers in animals. Lead acetate is used in coloring cotton, as coating for metals, as drier in paints, varnishes, pigments in inks, the dye in some permanent hair dyes, explosives and lavage for the treatment of ivy poisoning. Phosphate is mainly used as a stabilizer in plastics some special bottles. Primary exposure is through skin contact, inhalation and food.
Nickel and nickel compounds are associated with several cancers in rodents and mice. Human population studies linking exposure to nickel nasal cavity cancers, lung, and larynx possible. Nickel is used in dental fillings, copper and brass permanent magnets, batteries and emails.
Diesel exhaust particles
Diesel exhaust particles are suspected to be carcinogenic due to increased rates of lung cancer found in occupational groups exposed to diesel exhausts gases, for instance railway workers, workers in mines, workers at car service from trucking companies, mechanics cars, those who work around diesel generators. The risk of cancer from exposures lowest in everyday life is unknown.
7. Toxins from fungi
Aflatoxins are cancer-causing substances produced by certain types of fungi that grow on food. Corn and peanuts are the most common foods that grow these fungi. Meat, eggs and milk from animals that eat contaminated food are other sources of exposure. Workers farmers a potential increased risk if they inhale air contaminated by dust grains. Peanuts are investigated for aflatoxins in many countries. The risk of exposure to aflatoxins is greater in developing countries where screening is not for fungi.
8. Vinyl Chloride
Vinyl chloride, a colorless gas, is a human carcinogen associated with lung cancer and angiosarcoma of the liver and brain. He is almost exclusively used in US plastics industry in the manufacture of many consumer products, including containers, packaging foil, electrical, water and drainage pipes, floors, windows and credit cards. Source vinyl chlorides major release in the environment is believed to be plastic industry. People living near the factories of plastics are exposed by breathing contaminated air, but exposure of the general population who live away from factories is virtually zero.
Benzidine was one of the first chemical identified as being associated with an increased risk of cancer in humans. In the early 1921 reported an increased number of cancers associated with benzidine, a compound used in production of more than 250 benzidine dyes for textiles, paper and leather products. Exposure to benzidine dyes or bezidine is now known to be carcinogenic. Benzidine dyes degrade once you are inside the body. In most cases dyes that are metabolized to benzidine are risky only in the vicinity of dyes and pigments factories where debris can escape or be evacuated.
Some drugs used to treat cancer (cyclophosphamide, chlorambucil, melphalan) have been shown to increase the occurrence of secondary cancers, including leukemia. Other drugs used as immunosuppressive cyclosporine and azathioprine example for organ transplant patients also are associated with an increased risk of cancer, particularly lymphoma. However, FDA has decided that the benefits of these life-saving drugs outweigh the additional cancer risk appearing a few years later. It is recommended that people weigh the risks and benefits involved the use of a drug with a physician or specialist in health issues.
Estrogens used to treat symptoms of menopause side (heat, dryness of mucous membranes, osteoporosis) has been shown to increase the incidence of endometrial cancer, breast cancer. Progesterone used in combination with hormone replacement estrogen therapy in older women reduces the risk of endometrial cancer, but increases the risk of breast cancer, cardiac disease, stroke and clotting disorders. Long-term use of oral contraceptives reduced the risk of endometrial and ovarian cancer but increases the incidence of breast and liver cancer.
Using Tamoxifen, a synthetic hormone used in preventing breast cancer relapse after surgery was associated with an increased risk of uterine cancer, stroke and clotting disorders.
Diethylstilbestrol (DES) is a synthetic form of estrogen prescribed to pregnant women in the period 1940-1971. It was found that girls born to mothers who received DES are at increased risk of developing cervical or vaginal adenocarcinoma and mothers have a slightly increased risk of developing breast cancer. Based on this data is not used DES.
H. Some viruses and bacteria.
Infections with certain viruses or bacteria may increase the risk of cancer:
– Human papillomavirus (HPV): HPV infection is the leading cause of cervical cancer and anal cancer. Women who began sexual activity before 16 years old or have multiple sex partners are at increased risk of infection. Although HPV infection is the leading cause of cervical cancer, most infections do not cause cancer.
-Human T-cell leukemia / lymphoma virus (HTLV-1) infection increases the risk of a person HTLV1 for lymphoma or leukemia.
– Hepatitis B and C virus: Liver cancer can develop after many years of infection with virus B or C. In Asia and Africa HBV is acquired in childhood and is an increased risk of liver cancer. HBV infection is rare in the US, and increased incidence of liver cancer is due to infection with HCV. HBV and HCV infections are transmitted through blood products, injecting drug use and unprotected sex with multiple partners. To prevent infection with HBV there a vaccine for HCV infection but there is still no vaccine.
– Human immunodeficiency virus AIDS (AIDS). People who have HIV have an increased risk of lymphoma and a particular type of cancer called Kaposi’s sarcoma (angiosarcoma).
– Epstein Barr Virus: Epstein-Barr virus infection was associated with an increased risk of lymphoma. This virus also causes infectious mononucleosis.
– Human herpes virus 8 (HHV8) is a risk factor for Kaposi’s sarcoma
-Helicobacter Pylori. These bacteria cause stomach ulcers. It can cause gastric cancer and gastric lymphoma. However most of Helicobacter pylori infections cause no symptoms and no cancer.
I. Family history of cancer
Some cancers are more common in certain families than in the general population. For example, melanoma, breast, ovary, prostate and colon sometimes occur more frequently in certain families. Some cases of this type in a family may be due to inherited genetic changes that may increase the chance of developing cancer. However, environmental factors may also be involved. In most cases, multiple cases of cancer in a family are due to chance.
Hardcore drinkers (more than 2 drinks / day) have an increased risk of cancer, especially among those who smoke. Cancers associated with alcohol consumption are cancers of the oral cavity, oropharynx, larynx, liver, esophagus and breast. The risk increases with the amount of alcohol a person consumes. Patients should be advised to consume alcoholic beverages moderately consume it meant no more than 1 drink per day for women and two drinks per day for men. One drink means: 350ml beer with 5% alcohol, 145 ml of wine or 45 ml 12% alcohol spirit drink with 40% alcohol.
K. unhealthy diet, physical inactivity and overweight
Improper diet Some studies have shown that high consumers of red meat, canned meat, canned foods in salt and salt have an increased risk of colorectal cancer and gastric. There is also evidence that a diet rich in fruits and vegetables may decrease the risk of colorectal cancer, gastric and esophageal.
Overweight or obesity seems to be one of the most important modifiable cause of cancer after tobacco. Studies have shown a mixed population constant association between obesity and certain cancers: breast cancer in older women, endometrial, kidney, colon and esophagus.
Physical inactivity increases the risk of breast and colon cancer. The beneficial effect of physical exercise is higher in very active. It is estimated that inactivity and obesity account for 20-30% of cases of breast cancer (postmenopausal), colon, endometrial, kidney, and esophagus.
Having a healthy diet, physical activity and maintaining a healthy weight good may reduce cancer risk. A healthy diet includes foods rich in fiber, vitamins and minerals bread and whole grains, fruits and vegetables 5-9 meals / day. It also means a reduction of foods high in fat (butter, milk, red meat and fried foods).
A moderate physical activity can control weight and reduce fat corporeal. A moderate physical activity means a brisk walk t = 30 minutes, 5 days or more per week.
Risk factors in the most common cancers:
1. Smoking is the cause of 85% -90% of lung cancers. The risk is 30 times higher in smokers as nonsmokers. The risk decreases after smoking cessation, but this becomes significant after 5 years of stopping smoking. Smoking is the leading cause of lung cancer known. A lifetime smoker has a risk of lung cancer 20-30 times higher than a nonsmoker. Adenocarcinoma was always more common in women than in men, both in smokers as well as nonsmokers. Proof that the risk of lung cancer is higher in women than in men at similar levels of exposure to smoking has been weakened by recent studies in Europe, which concluded that the risk is similar in the two sexes.
2. Exposure to asbestos increases the risk of asbestosis lung cancer and acts synergistically with smoking. The risk factor for mesothelioma.
3. Exposure to radioactive dust and radon in uranium mines.
4. China is involved air pollution inside the house through food processing.
5. ENT cancers and esophageal cancer is associated with an increased risk of lung cancer due to the effect of “field cancerization” smoking product.
The other factors known to increase the risk of lung cancer are occupational exposure to asbestos, certain metals (nickel, arsenic, cadmium), radon and ionizing radiation. Yet their contribution to the number of cases occurring in the population is small. Diet rich in vegetables and fruits (especially green vegetables and carrots) may provide modest protection.
1. Sexual behavior
a) -The first sexual intercourse at a young age.
b) -The first pregnancy at a young age.
c)- Multiple sexual partners.
d) -The use of oral contraceptives or contraceptive barriers.
High parity was long recognized as a risk factor for cervical cancer, HPV infection parity but the relationship is not safe. The number of full-term pregnancy was associated with increased risk regardless of age at first pregnancy. These data were real if the analysis was limited to patients with HPV infection for seven or more pregnancies versus no pregnancy (19). Long-term use of oral contraceptives has been associated with cancer of the cervix, but the relationship with HPV infection was not sure. Compared with women who have never used oral contraceptives, those who had used oral contraceptives for more than five years had no increased risk of cervical cancer. The overall risk for women who had used oral contraceptives for 5-9 years was 2.82. and for those who have used ≥ 10 years 4,03.Riscul overall risk was associated with increased use of oral contraceptives is proportional to the duration of use. Women who began sexual activity before age 16 and women with multiple sexual partners are at increased risk of infection with HPV (human papilloma virus) and of developing cervical cancer. We recommend regular gynecological exam at the onset of sexual activity or at age 18. Prevention of sexually transmitted diseases reduces cervical cancer risk.
2. Infection with HPV
In practice HPV is the most common sexually transmitted infection (STI) with a standardized prevalence by age group 10.5%. In U.S. it affects 6 million individuals aged 15-24. Infection with human papilloma virus (HPV) types 6,11,16,18,31,33 is a particularly important risk factor.
Molecular techniques for finding human papilloma virus DNA are highly sensitive and specific. Epidemiological studies have demonstrated convincingly that the major risk factor for development of pre-invasive carcinoma and invasive cervix is HPV infection, which far outweighs other known risk factors such as multiple marriages, increased number of sexual partners, young age at first intercourse, socioeconomic status low positive history of smoking. Some patients with HPV infection appears to present a low risk for development of pre-invasive and invasive malignancies, while others appear to be at increased risk and are candidates for intensive Screening of programs and / or early intervention. Complications of HPV can be classified according to cell proliferation: benign nevi (condyloma acuminata or papillomas) or precancerous growths and cancerous anogenital tract inferior (LGT) and upper aero-digestive tract (UADT). The first damage caused by the most common are 2 types of low oncogenic risk HPV type 6 and 11 and cancerous lesions of the most aggressive and common types of HPV increased oncogenic risk (HR-HPV) type 16 and type 18.
From a million Papanicolau test (Pap) cervical squamous intraepithelial lesions reported as low grade (LSIL) in the US, 15% are caused by HPV type 6 or type 11. About 50% of vaginal lesions, vulvar and existing epithelial (prevalence) HPV types 6 or 11 are home.
In total 70% of the 493,000 cases of cervical cancer diagnosed are determined by the type 16 or 18 .. The median age at diagnosis is 45 years. The vaccine is made from the major capsid protein L1 of HPV naturally. L1 capsid protein when it is inserted in fungi or insects like virus assembles itself in particle (VLP virus-like particle which are similar to the external envelope of natural HPV. The vaccine is manufactured by Merck (USA) and Glaxo-Smith-Kline (Belgium). Since there VLPs are recombinant proteins naked viral DNA, they lack oncogenic properties and in addition are nontoxic and non-infectious. Studies have clearly shown that VLP vaccine generate neutralizing antibodies that prevents the HPV infection and squamous epithelial cells. The vaccine produced by GSK called Cervarix, is produced by fruit moth is a bivalent formulation of HPV L1 VLP type of 16 and 18 and an adjuvant (aluminum salts and monophosphoryl lipid A). Merck has manufactured a vaccine called Gardasil / Silgard the fungus Saccharomyces cerevisiae , is a vaccine containing qadrivalent VLPs URL and HPV types 6, 11, 16, 18, and adjuvant is an aluminum salt. Currently Gardasil is licensed in over 55 countries including 25 European countries, for children and teenagers 9-15 years and in adult females aged 16-26 years. The vaccine is administered intramuscularly in three doses 20-40μg per dose in a period of 6 months.
There is now a vaccine that protects against two HPV types that cause most cervical cancers (types 16 and 18). The vaccine is recommended for girls and women between 9-26 years before they make contact with HPV. The vaccine may also benefit women who are sexually active and have not yet been infected with HPV. The vaccine prevents HPV infection but do not get rid of it once infection has occurred.
Women who have never been infected with HPV, the vaccine protects against 7 out of 10 cases of cervical cancer is safe, very efficient and has fewer side effects.
About 95% of women with invasive cancer of the cervix have evidence of HPV infection.
Many women with HPV infection never develop invasive cancer however; so this infection is necessary but not sufficient for the development of invasive cancer. Although mortality from cervical cancer increases with age (maximum mortality for white is between 45 and 70 years) the prevalence of CIN is highest in women between 20-30 years. Mortality is rare among women younger than 30 years; HSIL is rare among women older than 65 years who were previously tracked through screening. Approximately 70% of ASCUS and CIN1 lesions regress in six years, while about 6% of CIN1 lesions progress to CIN 3 or worse. Aprox 10% -20% of women with CIN 3 lesions progress to invasive cancer.
Non- invasive squamous cell cervical abnormalities are graded histologically as cervical intraepithelial neoplasia (CIN) 1, CIN2sau CIN3 in agreement with the severity replaceable epithelial cell changes and the percentage of abnormal cell growth. CIN 3 is a reasonably reproducible diagnostic and has a 30% risk of turning into invasive cancer after several years if untreated. CIN 2 has a poor reproducibility and biological behavior is variable. CIN 3 is therefore a more rigorous endpoint for clinical trials.
3. Smoking may be associated with an increased risk of squamous cell cancer of the cervix. The risk increases with the duration and intensity of smoking. Case-control studies of HPV infected women examined the effect of different types and levels of exposure to tobacco and found similar data. Data and studies showing the opposite exist.
Multiple studies have shown an association between intake of certain micronutrients and lower risk of cervical cancer, but data are conflicting. Oral folates proved to have no protective effects.
75% of patients with breast cancer have no risk factor.
A. Low risk factors for breast cancer (relative risk of 1.2 -1.5 higher than normal)
– Nulliparous (no births)
– Age> 30 years at first pregnancy
– The occurrence of menarche (first menstruation) to <11 years
– Menopause> 55 years
– Alcohol consumption increases breast cancer risk. For each 10 g / day of alcohol increases the risk by 10% (Smith-Warner et al2001a, 2001b)
– Diet (red meat intake may increase risk of breast cancer (Dai et al, 2002). Still other studies have shown a correlation between eating meat or meat products and breast cancer (Missmer et al, 2002). Combination with fat intake, fruit and vegetable is low (Smith-Warner et al2001a, 2001b)
– Hormone replacement therapy used long term
– High socioeconomic level
– Personal history of ovarian, endometrial, colon
Environmental Risk Factors (relative risk 2-4 times higher than normal).
2. Women with a family history of breast cancer in first degree relatives 1 (mother, daughter, sister) shows a relative risk of 1.7 compared to normal, and if the disease started premenopausal risk is 3 times higher than normal.
3. Age greater than 40 years.
The incidence of breast cancer is:
at 30-34 years of 24.4 per 100,000 women,
the incidence is 45-49 years 195.7 per 100,000 women,
in 60-64 years the incidence is 347 per 100,000 women,
from 70-74 years the incidence is 455 per 100,000 women.
4. Personal history of breast cancer. Women with breast cancer have a risk of developing a new breast cancer by 1% per year.
5. Ductal hyperplasia or atypical lobular without
6. Parity. Women nulliparous or having first child after age 30 have a 3-4 times greater risk than women who gave birth before age 18.
7. Mammographic density occupying> 50% of the breast.
C. Factors with greater risk (relative risk increase> 4 times the normal).
1. Hereditary breast cancer is 5-8% of all cases. Mutations in the genes BRCA- BRCA- 1 and 2 are associated with an increased risk for breast cancer, ovarian cancer, pancreatic cancer.
A woman with BRCA-1 gene mutation have a lifetime risk of developing breast cancer by 56-85% and 15% -45% of developing ovarian cancer.
Women with mutations in the BRCA-2 lifetime risk of developing breast cancer is less than 60% at 70 years and 10% for ovarian cancer. Men with BRCA-2 mutations have a risk of developing life breast cancer of 6.5%.
Genetic testing is indicated to:
– Those with breast or ovarian cancer to 2 ï,³ 1 or 2 degree relatives with breast cancer or ovary.
– People with breast or ovarian cancer by 1 degree relative 1 or 2 in which the ovary or breast cancers occurring before 45 years.
– Those with breast or ovarian cancer premenopausal with multiple cancers.
– relatives with breast or ovarian cancer with mutations in the BRCA genes
2. Lobular carcinoma in situ is associated with a risk of invasive breast cancer 8-11 times the normal.
3. Lobular hyperplasia atypical
4. Family of history bilateral breast cancer or cancer of the breast in premenopausal mother, grandmother, sister, daughter, aunt or breast or ovarian cancer mother, grandmother, sister, aunt.
5. Mammographic density occupying> 75% of the breast.
Adenomatous family polyposis
1. Peutz- Jeghers Syndrome
2. Juvenile adenomatous polyposis
3. Non-polipoid hereditary colon cancer
4. Family history of colorectal polyps or cancer
5. Inflammatory Bowel Disease:
• ulcerative colitis
• Crohn’s disease
6. Personal History:
• colorectal carcinoma,
• colorectal polyps,
• pelvic irradiation, cholecystectomy,
1. Diet. They are involved:
Meat and fish dishes very salty, smoked foods.
Diet low in fruits and vegetables.
Increased intakes of nitrates in drinking water.
2. Helicobacter pylori infection increases the risk of gastric cancer by 3-6 times than normal.
3. Diseases considered gastric cancer precursors
a) Achlorhydria increase gastric cancer risk of 4-5 times the normal.
b) Pernicious anemia increases the risk 18 times the normal.
c) Atrophic gastritis.
d) Hypertrophic gastritis (Menetrier disease)
e) Intestinal metaplasia associated with intestinal type gastric cancer
f) Adenomatous polyp stomach: the risk of gastric cancer is 10-20%
4. Smoking, age> 50 years, blood group
1) viral liver infection and cirrhosis B and C
2) chemical carcinogens (aflatoxin B)
3) Contamination of drinking water channel
4) Alcohol, smoking, torotrastul, androgenic steroids
5) Hemochromatosis, Budd-Chiari syndrome
Cancer of the endometrium (uterine)
3. Infertility, nulliparous women
6. Polycystic ovarian disease
7. Family history of cancer
1. Smoking is the only identified risk factor. About 30% of pancreatic cancers are attributable to smoking. Smokers develop this disease 2-3 times more often than non-smokers.
2. Drinking coffee and alcohol is unlikely to constitute risk factors for pancreatic cancer
3. Fat diet. There is a strong correlation between body fat and abdominal and pancreatic cancer. Foods that have a high content of folates have a protective role.
4. Partial gastrectomy
5. Chronic pancreatitis
6. Type II Diabetes increases the risk of pancreatic cancer by about 50%, and studies have found a positive correlation between obesity and pancreatic cancer.
7. Hereditary. The increased risk of pancreatic cancer is increased (18 times) in families that first-degree relatives have pancreatic cancer.
1. Age: Epithelial ovarian cancer is a disease of older women. The incidence rate increases with each decade of life and reaches peak at the end of the 7th decade. Except for hereditary forms of the disease is unknown epithelial ovarian cancer before 40 years.
2. Genetic characteristics: about 5% -10% of ovarian epithelial cancers result from an inherited predisposition and identified three distinct patterns:
a). Headquarters specific ovarian cancer syndrome (10% -15%) of all cases. The most important risk factor for ovarian cancer is a family history of ovarian cancer in first-degree relatives (mother, daughter or sister). These women have 4% -7% lifetime chance of developing epithelial ovarian cancer until the age of 70 years with a relative risk of 3.1. The greatest risk occurs in women with 2 or 3 degree relatives with epithelial ovarian cancer (Stratton 1998). In most affected families there were found mutations in the BRCA1 gene.
b). Breast-ovarian cancer syndrome ovarian cancer in those families is characterized by multiple cases of breast and ovarian cancer in successive generations, a relatively early onset (premenopausal) and evidence of both paternal and maternal transmissions. Hereditary syndrome was due to chromosome 17q mutation of the BRCA1 gene 12-21 (81% of cases) and 13q chromosome less mutation on BRCA2 gene. The mode of transmission is autosomal dominant with variable penetrance, which implies that a single mutant allele is sufficient to promote breast or ovarian cancer and each child has a 50% chance of inheriting a mutant allele. In these families the risk of breast cancer is 35% -85% and 15% of ovarian cancer 60% (Couch 1997; Whittemore 1997).
c. Lynch II syndrome or hereditary nonpolipoid colorectal cancer syndrome. (HNPCC) In HNPCC the increased risk for ovarian cancer is associated with an excess of colorectal and endometrial cancer (Lynch 1998). This syndrome could be due to an inherited defect in one of four genes inadequate DNA repair (hMSH2, hPMS1, hMLH1, hPMS2). The risk for ovarian cancer was 12% and 80% for colorectal cancer.
Prophylactic oophorectomy Patients with a family history suggestive of inherited ovarian cancer should be offered genetic testing checkup. The potential benefit of genetic testing for BRCA mutations include the identification of women at increased risk of developing ovarian cancer and cancer of the breast, maximize surveillance measures for early detection of the disease, the possibility of offering surgical prophylaxis introduction pharmacological interventions and lifestyle. Currently oophorectomy’s prophylactic benefit has not been established. Women with mutations in the BRCA1 / BRCA2 should be counseled that this surgery is a possible treatment option. Numerous reports have described the primitive peritoneal cancer, ovarian cancer similar to 1.8% -10.7% of patients who underwent prophylactic oophorectomy. Prophylactic bilateral oophorectomy may provide benefit for women at high risk for ovarian cancer. However, this process is not completely protective against peritoneal cancer. Patients with HNPCC syndrome have genetic counseling and should be offered prophylactic surgery (hysterectomy and salpingo oophorectomy prevention) to reduce the risk of gynecological malignancies.
3. Hormonal Features
The use of exogenous hormones for menopause symptoms may be associated with an increased risk of ovarian cancer. It was shown that prolonged periods of hormone therapy replacement (> 5-10 years) confer an increased risk of 1.5- 2 times. A decreased risk of ovarian cancer following the use of oral contraceptives for 5-10 years has been observed. Lactation is associated with a decreased risk of ovarian cancer. Excess weight confers a moderate increase in risk for ovarian cancer.
4. Environmental characteristics diet rich in meat and low in vegetables is associated with an increased risk of ovarian cancer). Women who consume large amounts of low fat milk, or lactose calcium had a lower risk of ovarian cancer. Exposure to talc or asbestos may initiate ovarian carcinogenesis. In smoking women there is an increased risk of ovarian cancer in general and mucinous tumors especially.