Epidemiology of Cancer PDF

20 Neoplasia II: EPIDEMIOLOGY OF CANCER  Incidence of cancer Geographic and environment variables. Age and cancer Genetic and nongenetic predisposition in cancer CANCER INCIDENCE Cancer incidence rate is the Cancer incidence varies number of new cancers of a based on...

20 Neoplasia II: EPIDEMIOLOGY OF CANCER  Incidence of cancer Geographic and environment variables. Age and cancer Genetic and nongenetic predisposition in cancer CANCER INCIDENCE Cancer incidence rate is the Cancer incidence varies number of new cancers of a based on specific site/type occurring in a 1. age specified population during a 2. gender year, usually expressed as the 3. geography number of cancers per 100,000 4. genetic population at risk. CANCER INCIDENCE Cancer incidence are reported 1. Based on gender Male and Female 2. Based on Age groups TEN MOST COMMON CANCER IN MALAYSIA AGE-SPECIFIC INCIDENCE IN MALES 1. AGE - incidence of cancer rise with age - accumulation of somatic mutation, failure of genetic repair in aging , reduced immune surveillance 2. in the young leukemia is the most common malignancy 3. in older age colorectal , lung and prostate cancer are more common 4. Leukemias in younger age are of high grade while older age of lower grade AGE-SPECIFIC INCIDENCE IN FEMALES 1. AGE - incidence of cancer rise with age - accumulation of somatic mutation, failure of genetic repair in aging , reduced immune surveillance 2. in the young leukemia is the most common malignancy 3. in older age breast , colorectal and lung are more common 4. Leukemias in younger age are of high grade while older age of lower grade 5. Breast cancer starts to decline after menopause because of the reduction of oestrogen. 0-14 years age group 15- 24 years age group 25-59 years age group 60-74 years age group ≥ 75 years age group GEOGRAPHIC  Geographical differences in cancer incidence are the consequences of environmental influence Kaposi sarcoma Aetiologic agent- Kaposi sarcoma herpesvirus-8 AIDS- defining malignancy Prevalence reduced due to effective antiretroviral treatment to control HIV infection ENVIRONMENTAL VARIABLES 1. Occupational (refer Table 6.2 Occupational cancers ; Robbins basic pathology) Agents Cancer Use in industry 1 Asbestos Lung carcinoma , construction , fire resistant textile mesothelioma , GIT industry, brake industry malignancy 2 Benzene Leukemia , Printing , paint, rubber industries. lymphoma Use as solvent 3 Vinyl chloride Angiosarcoma, liver Refrigerant , adhesive, Aerosol 4 Ethylene oxide Leukemia Fuit industry, textile industries 5 UVlight melanoma workers ENVIRONMENTAL VARIABLES 1. Occupational Agents Cancer Use in industry 6 Formaldehyde; Nasopharynx Embalmers; Formaldehyde Wood dust production; Laboratory workers; Medical personnel; Plywood production / 7 Arsenic and Prostate Rubber production industry inorganic arsenic compounds; 2. Alcohol abuse increase the risk of oropharynx , larynx, esophagus, colorectal cancer,carcinoma of the liver and breast cancer. 3. Smoking causal for cancers of the lung , mouth ,pharynx , larynx , esophagus , pancreas, 4. Diet : factors predispose to malignancy overweight Deficiency in vitamins Diet rich in animal fats 5. Reproductive - prolonged unopposed oestrogen stimulation 6. Infectious agent GENETIC PREDISPOSITION TO CANCERS Inheritance of cancer 1. Autosomal dominant 2. Autosomal recessive syndromes of defectiveDNA repair 3. Familial cancers GENETIC PREDISPOSITION TO CANCERS Inheritance of cancer (germline mutation) 1. Autosomal dominant Gene Predispose to RB Retinoblastoma p53 Li fraumeni syndrome APC Familial adenomatous poliposis/ colorectal adenocarcinoma NF1, NF2 Neurofibromatosis BRCA1, BRCA2 Breast and ovarian cancer GENETIC PREDISPOSITION TO CANCERS Inheritance of cancer Autosomal recessive syndromes of defectiveDNA repair 1. Xeroderma pigmentosus 2. Ataxia telangiectasia 3. Blooms syndrome 4. Fanconi's anaemia GENETIC PREDISPOSITION TO CANCERS Inheritance of cancer Familial cancers 1. Breast cancers 2. Ovarian cancers 3. Pancreatic cancers NON HEREDITARY PREDISPOSING CONDITIONS TO CANCERS (table 6.3 Robbins 11th ed) 1. Chronic inflammation Ulcerative colitis, Helicobacter pylori gastritis/ulcer, viral hepatitis 2. Precancerous conditions Barrets esophagus, chronic atrophic gastritis, cirrhosis of the liver, chronic irritation of the oral cavity, Marjolin's ulcer, neurofibromatosis 3. Immunedeficiency states Deficient in T cell immunity THANK YOU