Search

PURPOSE: To analyze the evidence available on risk reduction of colorectal cancer with postmenopausal hormone replacement therapy (HRT). BACKGROUND: Colorectal cancer is a major public health problem in the United States. Approximately 135,000 new cases will be diagnosed in 2001, and 56,000 will die of this disease. 1 It accounts for 15% of all cancers in men and women and, after lung cancer, is the second leading cause of cancer deaths overall and the first in women aged 75 and older. 1 Men and women have a 6% lifetime chance of developing a colorectal cancer; the lifetime risk of dying is 2.6%. 2 The incidence continues to rise throughout life, approximately doubling with each decade over the age of 50. The incidence is four to five times higher in people aged 65 and older; for women this ratio is higher for colorectal cancers than it is for cancer in general. More than two-thirds of colorectal cancer occurs in people aged 65 and older. 1 Overall 5-year survival is 57% and is somewhat worse in older people, even after adjusting for increases in other causes of death in older people. 2 There are many well-identified risk factors cited in the causation of colon cancer, and age is a dominant one for sporadic cases. 3 Many protective factors, such as diet high in fruits and vegetables, 4–6 folic acid supplements, 7 calcium supplements, 8 regular use of aspirin or nonsteroidal antiinflammatory drugs, 9,10 physical activity, 11 hydroxy methyl glutaryl coenzyme A reductase inhibitors, and hormone therapy, are being identified. There is now accumulating epidemiological and biological evidence 12–18 suggesting an inverse relationship between hormone use and incidence of colorectal cancers. A careful appraisal of a meta-analysis of the data available from many trials investigating this relationship is presented. DATA SOURCES:... [ABSTRACT FROM AUTHOR]