Oncology (Medicine) - Cancer Prevention and Screening PDF

(L1) cancer prevention and screening  LECTURE 01 CANCER PREVENTION AND SCREENING INCIDENCE  Cancer cases are rising as population ages  In 2013, 280,000 new diagnoses  80,000 additional cases in 2030  The probabil...

(L1) cancer prevention and screening  LECTURE 01 CANCER PREVENTION AND SCREENING INCIDENCE  Cancer cases are rising as population ages  In 2013, 280,000 new diagnoses  80,000 additional cases in 2030  The probability of getting cancer during your life time is:  39.3% for men  37.1% for women RISK FACTORS ① Age ⑦ Immunosuppression ② Alcohol ⑧ Infectious agents ③ Cancer causing substances ⑨ Obesity ④ Chronic inflammation ⑩ Radiation ⑤ Diet ⑪ Sunlight ⑥ Hormones ⑫ Tobacco Dr.Noaman Page 1  Medicine - Delta Semester (7) Cancer prevention and screening Cancer PREVENTION Definition  Prevention is defined as reduction in cancer mortality via reduction in incidence of cancer importance  It is estimated that 50% of cancer is preventable  Nine modifiable risks were identified among all cancer deaths: ① 30% were related to smoking ② 35% to diet. ③ 35% to other causes: 1. Viruses 3. Radiation 2. Hormones 4. Industrial carcinogens types ① Primary prevention ② Secondary prevention ③ Tertiary prevention Primary prevention 1 Principle  Reduce the incidence of cancer by: ① Avoiding carcinogen or altering its metabolism ② Life style or dietary practices ③ Increasing an individual’s resistance to these risk factors: 1. Immunization 2. Medical intervention (e.g. chemoprevention) 3. Risk-reducing surgical procedures Dr.Noaman Page 2  Medicine - Delta Semester (7) Cancer prevention and screening Notes  Life Factors have linked to a variety of malignancies, including the most common in the developed world: ① Lung ② Colorectal ③ Prostate ④ Breast cancer.  In a published study, participants who had all four lifestyle factors had approximately one third lower risk of cancer compared with those who had none of these factors: ① Never smoking ② Body mass index (BMI) < 30 ③ Physical activity > 3.5 hours weekly ④ Prudent diet (high intake of fruits, vegetables, and whole-grain bread and low meat consumption) 2 Methods ① Do not smoke. ② Avoid alcohol consumption ③ Avoid obesity. ④ Limit your intake of foods containing fats from animal sources. ⑤ Undertake some brisk, physical activity every day. ⑥ Increase the daily intake and variety of vegetables and fruit: eat at least five servings daily. ⑦ Care must be taken to avoid excessive sun exposure. ⑧ Preventing any exposure to known cancer-causing substances e.g. asbestos. ⑨ Participate in vaccination programs against hepatitis B virus infection, HPV. Dr.Noaman Page 3  Medicine - Delta Semester (7) Cancer prevention and screening Chemoprevention of cancer ① Breast Cancer:  Tamoxifen ② Colorectal Cancer:  Aspirin (≥325 mg)  Taken daily for five years, compared with no aspirin, decreased the incidence of colorectal cancer in the Cancer Prevention Study II Nutrition Cohort (RR 0.68).  Low dose aspirin (100 mg every other day), when compared with placebo, did not decrease the incidence of colorectal cancer Secondary prevention (screening) 1 Aim  Secondary prevention aims at detecting cancer at an early stage when treatment is more effective, leading to a higher rate of cure and a reduced frequency of the more serious consequences of disease. 2 Methods  Typically, in secondary prevention, the diagnostic procedure is directed at the period between the onset of the disease and the onset of symptoms (approximately the usual time of diagnosis). Dr.Noaman Page 4  Medicine - Delta Semester (7) Cancer prevention and screening Dr.Noaman Page 5  Medicine - Delta Semester (7) Cancer prevention and screening Tertiary prevention (concept of Adjuvant treatment) 1 Definition  Tertiary cancer prevention is usually defined as the prevention of loco-regional relapse and/or metastatic disease after – hopefully curative – primary treatment. 2 Aim  Tertiary prevention therefore embraces the expanding and important field of adjuvant therapy.  It is particularly successful in testicular cancers, breast cancer, colorectal cancer and bone sarcoma. Causes of death father 2. Multiple relatives > single relative 3. Multiple generations at early age > single generation at older age ③ Race:  African-American men are more than twice as likely to die from prostate cancer than Caucasian men Screening  Most effective method for detection is combined use of: ① Prostate Specific Antigen (PSA) ② Digital Rectal Exam (DRE)  ~15% of men with cancer have PSA 24% Suggests benign disease ③ 15-24% Grey area ① 5-alpha reductase inhibitors 3 Medications ② Oral Estrogen agents ③ LHRH agonists and antagonists 3 PSA Screening Guidelines ① Age 50 for men who are at average risk of prostate cancer and are expected to live at least 10 more years. ② Age 45 for men at high risk of developing prostate cancer. 1. African Americans 2. Men who have a first-degree relative (father or brother) diagnosed with prostate cancer at an early age (younger than age 65). ③ Age 40 for men at even higher risk  Those with more than one first-degree relative who had prostate cancer at an early age. Dr.Noaman Page 16