Paul F. Engstrom, MD

To treat, or not to treat-the decision to use adjuvant chemotherapy plagues medical oncologists and patients harnessed with the diagnosis of stage II colon cancer. A look to the literature does not simplify the decision, as significant controversy exists regarding the magnitude of benefit associated with 6 months of adjuvant chemotherapy. Dr. Kopetz and colleagues provide a well-organized review of the current literature examining the benefit of adjuvant chemotherapy in stage II disease, and discuss potential prognostic markers that may help determine who would most likely benefit from treatment.

With the aging of the Western population, cancer in the older person is becoming increasingly common. After considering the relatively brief history of geriatric oncology, this article explores the causes and clinical implications of the association between cancer and aging. Age is a risk factor for cancer due to the duration of carcinogenesis, the vulnerability of aging tissues to environmental carcinogens, and other bodily changes that favor the development and the growth of cancer. Age may also influence cancer biology: Some tumors become more aggressive (ovarian cancer) and others, more indolent (breast cancer) with aging. Aging implies a reduced life expectancy and limited tolerance to stress. A comprehensive geriatric assessment (CGA) indicates which patients are more likely to benefit from cytotoxic treatment. Some physiologic changes (including reduced glomerular filtration rate, increased susceptibility to myelotoxicity, mucositis, and cardiac and neurotoxicity) are common in persons aged 65 years and older. The administration of chemotherapy to older cancer patients involves adjustment of the dose to renal function, prophylactic use of myelopoietic growth factors, maintenance of hemoglobin levels around 12 g/dL, and proper drug selection. Age is not a contraindication to cancer treatment: With appropriate caution, older individuals may benefit from cytotoxic chemotherapy to the same extent as the youngest patients.

Prostate cancer is the most common form of cancer (except skin cancer) in men. Several factors have been associated with an increased risk for prostate cancer, including age, ethnicity, family history, lifestyle, and

Colorectal cancer is a major cause of death in the United States, where it accounts for approximately 57,000 deaths per year. Thus, the prevention of this disease would have a significant impact on public health. Chemoprevention is defined as the use of natural or pharmacologic agents to disrupt the process of carcinogenesis. Substances explored as chemopreventive agents in colorectal cancer include: (1) the nonsteroidal anti-inflamma-tory drugs (NSAIDS), which may inhibit the evolution and formation of adenomas by their inhibition of cyclooxygenase and decrease of prostaglandin synthesis; (2) antioxidants, such as vitamin E or C, which may modulate carcinogenic substances; and (3) folate and calcium, which may interfere with tumor cell growth and replication. Dietary intervention can be accomplished by decreasing fat intake and increasing fiber consumption, both of which have been linked to a lower incidence of colon cancer in multiple epidemiologic studies. This field is continuing to evolve. Hopefully, ongoing research efforts will offer a better understanding of the role of these and other substances in chemoprevention. This article summarizes the available data regarding dietary and pharmacologic approaches to colorectal cancer chemoprevention. [ONCOLOGY 1(13):89-98, 1999]