EPIDEMIOLOGY AND PREVENTION OF CANCERS

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1 EPIDEMIOLOGY AND PREVENTION OF CANCERS

2 KEY FACTS Most cancers develop as a result of exposure to modifiable risk factors! Most cancers have a long detectable preclinical phase which allows for early detection and effective treatment! WHO estimates that 40% of all cancer deaths are preventable. Tobacco and harmful alcohol use are among the most important risk factors for this disease.

3 LEADING CAUSES OF DEATH Pink: CVD Lightblue: cancer(europe: breastand lung) Dark blue: tbc Red: HIV/AIDS Orange: Cirrhosis of liver

4 CANCERS WORLDWIDE

5 CANCER INCIDENCE WORLDWIDE

6 CANCER MORTALITY WORLD WIDE

7 PREVALENCE 32.5 million people diagnosed with cancer within the five yearspreviously were alive at the end of Most were women after their breast cancer diagnosis (6.3 million), men after their prostate cancer diagnosis (3.9 million), and men and women after their colorectal cancer diagnosis (3.5 million) MALE FEMALE

8 HEALTHY YEARS OF LIFE LOST An estimated million years of healthy life were lost globally because of cancer in Colorectal, lung, female breast and prostate cancers were the main contributors in most regions of the world, explaining 18%- 50% of the total healthy years lost. MALE FEM.

9 CAUSES AND RISK FACTORS OF CANCER I. Genetic factors (BRCA1, BRCA2, FAP) Smoking (Of the 8.2million annual cancer deaths, 40% are preventable. Of these avoidable cancer deaths, tobacco accounts for 60%.) Alcohol (Harmful alcohol use causes cancer deaths) Obesity and overweight (Collectively, overweight and obesity, and physical inactivity account for colorectal cancer deaths each year, and breast cancer deaths each year.)

10 CAUSES AND RISK FACTORS OF CANCER II. Infectious agents Hepatitis B, C, HPV, H. pylori etc. Occupational and environmental agents Asbestos, arsenic etc. Ionizing and non-ionizing radiation Ionizing radiation is a well established carcinogen for certain cancers like lung, breast and thyroid cancer and most types of leukemia. Radon is the second most important risk factor for lung cancer after tobacco. Non-ionizing radiation (UV, sunbed) is risk factor for skin cancers. Medical procedures and drugs Chemotherapy (leukemia), immunosuppressive therapy (Non-Hodgkin lymphoma), radiotherapy (cancer in the irradiated organs), replacement estrogen therapy (endometrial cc), Phenacetin-containing analgesics (cancer of the renal pelvis )

11 APPROACHES OF PREVENTION I. Prevention at population level Minimizing environmental carcinogens (environment, workplace, food) Providing protection Vaccination Early detection Organized population screenings Increasing knowledge on cancers Education Research Cancer registries

12 APPROACHES OF PREVENTION II. Prevention at individual level PRIMARY PREVENTION Avoiding smoking Moderate alcohol consumption Safe sex Moderate sun-bathing / tanning Healthy diet Regular physical exercise Adaptive coping strategies and stress management SECONDARY PREVENTION Regular self-examinations Attending organized screening programs

13 PRIMARY PREVENTION Vaccination Avoiding tobacco Skin protection Limiting alcohol intake Keeping a healthy weight Healthy diet Decreasing exposure to environmental carcinogens (radon, asbestos)

14 CONTRIBUTION OF SELECTED RISK FACTORS TO CANCER DEATHS

15 VACCINATION I. The U.S. Food and Drug Administration approved a human papillomavirus (HPV) vaccine for females aged 9 26 and males aged It protects against the HPV types that most often cause cervical, vaginal, vulvar, and anal cancers.

16 HPV vaccination and cancers Two HPV vaccines are currently on the market: Gardasil and Cervarix. Both vaccines protect against the two HPV types (HPV-16 and HPV-18) that cause 70% of cervical cancers, 80% of anal cancers, 60% of vaginal cancers, and 40% of vulvar cancers. These HPV types also cause most HPV induced oral cancers, and some other rare genital cancers. Gardasil also protects against the two HPV types (HPV-6 and HPV-11) that cause 90% of genital warts. Boosters are not needed. Overall, about 30 percent of cervical cancers will not be prevented by these vaccines.

17 VACCINATION II. Hepatitis Bis a liver disease caused by the Hepatitis B virus (HBV). It ranges in severity from a mild illness, lasting a few weeks (acute), to a serious long-term (chronic) illness that can lead to liver disease or liver cancer. Thehepatitis B vaccineis available for all age groups to prevent HBV infection.

18 AVOIDING TOBACCO Compared to nonsmokers, men who smoke are about 23 times more likely to develop lung cancer and women who smoke are about 13 times more likely. Smoking causes about 90% of lung cancer deaths in men and almost 80% in women. Smoking also causes cancer of the larynx,oral, esophagus, bladder, kidney, pancreas, cervix, and stomach, and causes acute myeloid leukemia.

19 SKIN PROTECTION Exposure to ultraviolet (UV) rays from the sun and tanning beds appears to be the most important environmental factor involved with developing skin cancer. There isreasonably consistent evidence for a positive association between intermittent sun exposure and melanoma(rr=1.61).

20 LIMITING ALCOHOL INTAKE Studies around the world have shown that drinking alcohol regularly increases the risk of getting mouth, voice box, and throat cancers. Daily consumption of around 50g of alcohol doubles or triples the risk for these cancers, compared with the risk in nondrinkers. A large number of studies provide strong evidence that drinking alcohol is a risk factor for primary liver cancer, and more than 100 studies have found an increased risk of breast cancer with increasing alcohol intake. The link between alcohol consumption and colorectal (colon) cancer has been reported in more than 50 studies.

21 KEEPING A HEALTHY WEIGHT Research has shown that being overweight or obese substantially raises a person's risk of getting endometrial (uterine), breast, prostate, and colorectal cancers.

22 HEALTHY DIET The EPIC(European Prospective study Into Cancer)study is the largest study into diet and cancer to date, and it involves over 500,000 people from 10 European countries who are being followed for many years. Estimates show that one in every ten cancers is caused by an unhealthy diet. Cancer preventive diet consist of: - High intake of vegetables, fruits and fibers - Low intake of red meat, salt

23 FRUITS AND VEGETABLES Research suggests nearly one in 20 cancers in the UK may be linked to diets low in fruit and vegetables. Fruit and vegetables are an important part of a healthy diet and are an excellent source of many vitamins and minerals, as well as fibre. Contain high levels of antioxidants, which may protect against oxidative stress, thus preventing not only cancers but also cardiovascular diseases and 200 other diseases.

24 FIBERS I. Much research has shown that bowel cancer is less common in people who eat lots of fiber. Fiber could help protect againstbowel cancerin a number of ways. Fiber increases the size of stools, dilutes their contents, and helps people have more frequent bowel movements. This reduces the contact time between the bowel and harmful chemicals in the stools. Fiber may also help gut bacteria to produce helpful chemicals that change the conditions in the bowel. All of these things help to reduce the risk of cancer

25 FIBERS II. Simple ways to add more fiber to your diet: - Use brown rice instead of white rice - Substitute whole-grain bread for white bread - Choose a bran muffin over a croissant or pastry - Snack on popcorn instead of potato chips - Eat fresh fruit such as a pear, a banana, or an apple (with the skin) - Have a baked potato, including the skin, instead of mashed potatoes - Enjoy fresh carrots, celery, or bell peppers with a hummus or salsa, instead of chips and a sour cream dip - Use beans instead of ground meat in chili, casseroles, tacos, and even burgers (bean burgers can taste great)

26 READ MEATS Many studies have shown that eating lots of red and processed meat can increase the risk of bowel cancer, and possibly stomach and pancreatic cancer. Red and processed meats contain a red pigment called haem. Haem could irritate or damage cells in the bowel or fuel the production of harmful chemicals by bacteria in the gut, which could lead to a higher risk of cancer developing. Chemicals called nitrates and nitrites are often used to preserve processed meat. In the bowel nitrites can be converted into cancer causing-chemicals called N-nitroso compounds (NOCs). Cooking meat at high temperatures such as grilling or barbecuing can produce cancer-causing chemicals called heterocyclic amines (HCAs) and polycyclic amines (PCAs).

27 SALT Salt could increase cancer risk by damaging thestomachlining causing inflammation, or by making the stomach lining more sensitive to cancer-causing chemicals. Salt could also interact with Helicobacter pylori that is linked to both stomach ulcers and stomach cancer.

28 RADON AND LUNG CANCERS Radon is the second most important risk factor for lung cancer after tobacco. Radon is a gas that occurs naturally from the breakdown or the radioactive decay of uranium. It enters through cracks in solid floors and walls construction joints, gaps in suspended floors, gaps around service pipes, cavities inside walls, or the water supply. To decrease radon exposure vents can be built. If not, opening windows at regular intervals especially in subterrain levels may be helpful.

29 SCREENING IN PRIMARY PREVENTION Screening for hereditary risk factors (e.g. BRCA1, BRCA2) Women with either BRCA mutation have a 65%- 74% chance of developing breast cancer in their lifetime. Lifetime risk of ovarian cancer is 39%-46% in women with a BRCA1 mutation and 12-20% in women with a BRCA2 mutation. For women with a BRCA mutation, experts recommend periodic screening with CA 125 and transvaginalultrasonography beginning between the ages of 30 and 35 years or 5-10 years earlier than the earliest age of first diagnosis of ovarian cancer in the family. The Angelina Jolie paradigm (?)

30 SURGICAL PREVENTION Prophylactic mastectomy has been a mainstay of management ofbrcamutation carriers because of their markedly increased risk of breast cancer. The breast cancer risk reduction associated with bilateral prophylactic mastectomy is approximately 90%. Prophylactic salpingo-oophorectomy has primarily been studied in women withbrca1orbrca2germlinemutations, although it is also appropriate for women with Lynch syndrome (hereditary nonpolyposiscolorectal cancer) and some other hereditary syndromes. Individuals with the hereditary syndrome familial adenomatous polyposis are often afflicted with hundreds to thousands of colorectal polyps and have a virtual certainty of developing colorectal cancer in their lifetime if their disease is unchecked. A standard risk-reducing measure in this population is prophylactic colectomy, which is generally undertaken at the appearance of adenomas in known mutation carriers.

31 SCREENING IN SECONDARY PREVENTION Recommended Breast cancer Cervical cancer Colorectal cancer Lung cancer Not recommended Ovarian cancer Prostate cancer Skin cancer

32 BREAST CANCER I. Mammograms are the best way to find breast cancer early, when it is easier to treat. Having regular mammograms can lower the risk of dying from breast cancer. If you are 50 to 74 years old, be sure to have a screening mammogram every two years. If you are 40 to 49 years old, talk to your doctor about when to start and how often to get a screening mammogram

33 BREAST CANCER II.

34 CERVICAL CANCER I. The Pap test can find abnormal cells in the cervix which may turn into cancer. Pap tests also can find cervical cancer early, when the chance of being cured is very high. The Pap test (or Pap smear) looks forprecancers,cell changes on the cervix that might become cervical cancer if they are not treated appropriately. The test is recommended for all women between the ages 21 and 65 years old.

35 CERVICAL CANCER II.

36 COLORECTAL CANCER I. Colorectal cancer almost always develops from precancerous polyps in the colon or rectum. Screening tests can find precancerous polyps, so they can be removed before they turn into cancer. Screening tests also can find colorectal cancer early, when treatment works bets. Colorectal cancer screening is recommended for men and women aged using high-sensitivity fecal occult blood testing (FOBT), sigmoidoscopy, or colonoscopy. (The decision to be screened after age 75 should be made on an individual basis. If you are older than 75, ask your doctor if you should be screened.)

37 COLORECTAL CANCER II.

38 LUNG CANCER The U.S. Preventive Services Task Force recommends yearly lung cancer screening with low-dose computed tomography (LDCT) for people who have a history of heavy smoking, and smoke now or have quit within the past 15 years, and are between 55 and 80 years old. NB! The most important thing you can do to lower your lung cancer risk is to quit smoking and avoid secondhand smoke.

39 OVARIAN CANCER Ovarian cancer is one of the leading causes of death fromcancerof the female reproductive system There is no evidence that any screening test reduces deaths from ovarian cancer. Screening possibilities: Pelvic exam Transvaginal ultrasound CA-125 assay

40 PROSTATE CANCER The U.S. Preventive Services Task Force recommends against prostate specific antigen (PSA)-based screening for men who have no symptoms. Screening possibilities Digital rectal exam (DRE): A doctor or nurse inserts a gloved, lubricated finger into the rectum to estimate the size of the prostate and feel for lumps or other abnormalities. Prostate specific antigen (PSA) test: Measures the level of PSA in the blood.

41 BENEFITS AND LIMITAIONS OF PSA SCREENING A PSA test may help detect prostate cancer at an early stage. The limitations of PSA testing include: PSA-raising factors.besides cancer, other conditions that can raise PSA levels include an enlarged prostate (benign prostatic hyperplasia, or BPH) and an inflamed or infected prostate (prostatitis). Also, PSA levels normally increase with age. PSA-lowering factors. Certain drugs used to treat BPH or urinary conditions may lower PSA levels. Large doses of certain chemotherapy medications can also lower PSA levels. Misleading results. The test doesn't always provide an accurate result. An elevated PSA level doesn't necessarily mean you have cancer. And in some cases, a normal PSA level does not completely rule out prostate cancer. Overdiagnosis. Studies have estimated that between 17 and 50 percent of men with prostate cancer detected by PSA tests have tumors that wouldn't result in symptoms during their lifetimes. These symptom-free tumors are considered overdiagnoses identification of cancer not likely to cause poor health or to present a risk to the man's life.

42 SKIN CANCER The U.S. Preventive Services Task Force has concluded that there is not enough evidence to recommend for or against routine screening (totalbody examination by a clinician) to find skin cancers early. Regular skin checks by a doctor are important for people who have already had skin cancer. However physicians should: Be aware that fair-skinned men and women aged 65 and older, and people with atypical moles or more than 50 moles, are at greater risk for melanoma. Look for skin abnormalities when performing physical examinations for other reasons. Everyone should be informed to report any worrisome changes to the doctor as soon as possible.

43 TERTIARY PREVENTION Tertiary cancer preventionincludes monitoring for and preventing recurrence of the originally diagnosed cancer and screening for second primary cancers and long-term effects of treatment in cancer survivors. The focus of this form of prevention is aimed at detecting complications and second cancers in long-term survivors when treatment is most likely to be effective and ultimately improve their quality of life.

44 WESTERNISATION TRENDS As low human developmental index (HDI) countries become more developed through rapid societal and economic changes, they are likely to become westernised. As such, the pattern of cancer incidence is likely to follow that seen in high HDI settings, with likely declines in cervix uteri and stomach cancer incidence rates, alongside increasing incidence rates of female breast, prostate and colorectal cancers. This westernisation effect is a result of reductions in infectionrelated cancers, outweighed by an increasing burden of cancers more associated with reproductive, dietary and hormonal risk factors.

45 PROJECTIONS If recent trends in major cancers are seen globally in the future, theburden of cancer will increase to 23.6 million new cases each year by This represents an increase of 68% compared with 2012 (66% in low and medium HDI countries and 56% in high and very high HDI countries)

46 SOURCES

47 THANK YOU FOR YOUR ATTENTION!