Pocket Oncology (Pocket Notebook Series), 1st Ed.


Anita Kumar and Victoria Blinder

Cancer Epidemiology Research Methods

• Epidemiology: Study of distribution, determinants, & outcomes of cancer at a population level; applies public health or policy perspective, rather than the perspective of an individual pt

• “Efficacy”: Treatment demonstrates an effect, often in a clinical trial, vs. “effectiveness”: Effect in “real-world,” at the population level

• Observational studies: Cross-sectional, cohort, & case-control

• Experimental studies: Individual-based vs. community-based

• Epidemiology research can include analyses of patterns of care, comparative outcomes, cost-effectiveness, & health care disparities.

• A classic study showed women w/breast cancer who are uninsured or on Medicaid had a higher risk of death compared to women w/private insurance (NEJM 1993;329:326).

• Molecular & genetic epidemiology: Identification of biomarkers & genetic features linked to cancer susceptibility

Cancer Cases and Deaths

U.S. cancer incidence trends 1998–2008 (ACS Cancer Facts & Figures 2012):

• Cancer is a disease of older individuals, incidence ↑ w/aging population

• ↓ in lung cancer due to decline in smoking

• ↓ in colorectal, cervical cancer w/early detection, screening

• ↓ in stomach cancer due to ↓ in H. pylori infection

• ↓ in prostate cancer incidence due to ↓ in PSA screening

• Stable breast cancer incidence (period of decline in 2002–2003 due to ↓ in HRT use)

• ↑ incidence of HPV-related oropharyngeal cancer, esophageal adenocarcinoma, liver & intrahepatic bile duct, pancreas, thyroid, melanoma of skin, & kidney cancer

Figure 1-1

Global Cancer Epidemiology

• Temporal trends: (1) Cancer incidence is ↑ in the developing world due to ↑ longevity, & growing adoption of Western diet, physical inactivity, & tobacco use; (2) ↓ incidence of cancers due to infectious etiologies (stomach, liver, uterine cervix)

• Environmental factors that contribute to geographic distribution of cancer, eg, stomach cancer incidence rates highest in Eastern Asia & Central/Eastern Europe due to chronic H. pylori infection & diets high in salt & processed foods, low in fresh fruits & vegetables

• Migration studies: Japanese migrants to California have lower rates of gastric cancer compared to country of origin, but higher than California residents (Cancer 1965;18:656)

Etiologic Agents in Cancer