© 2004 by Oxford University Press
© 2004 Oxford University Press
IN THIS ISSUE |
Whether the prostate-specific antigen (PSA) response to salvage hormonal therapy can act as an intermediate end point for prostate cancer–specific mortality (PCSM) remains unclear. D’Amico et al. (p. 509) evaluated whether PSA response—the ratio of the rate of PSA change after salvage hormonal therapy to the rate of PSA change before salvage therapy—is associated with PCSM by using data from a single institution and two pooled multi-institutional databases. They found that PSA response was statistically significantly associated with time to PCSM following salvage hormonal therapy; however, its constituents (i.e., pre–hormonal and post–hormonal PSA slopes) were not. They also found that patients with a PSA response less than or equal to 1 had a shorter time to PCSM than patients with a PSA response of more than 1. The authors conclude that PSA response to salvage hormonal therapy can serve as an intermediate end point for PCSM in patients with a rising PSA level following surgery or radiation therapy.
ER Status of Primary and Contralateral Breast Cancers
Tamoxifen reduces the risk for contralateral breast cancer and primarily benefits women with estrogen receptor (ER)-positive disease. Using National Surgical Adjuvant Breast and Bowel Project trial data, Swain et al. (p. 516) determined the relationship between the ER status of primary and contralateral breast cancers and whether tamoxifen treatment affects this relationship. Among patients who did not receive tamoxifen, 89% with an ER-positive primary cancer had an ER-positive contralateral breast cancer and 70% with an ER-negative primary cancer had an ER-negative contralateral breast cancer. Among patients who received tamoxifen, 56% with an ER-positive primary cancer had an ER-positive contralateral breast cancer and 78% with an ER-negative primary cancer had an ER-negative contralateral breast cancer. The authors conclude that the ER status of primary breast cancer was associated with that of the contralateral breast for patients not receiving tamoxifen, and that patients with an ER-positive primary cancer who received tamoxifen had fewer ER-positive contralateral breast cancers, possibly as a result of tamoxifen treatment.
In an accompanying editorial (p. 497), Stearns and Davidson discuss how the relationship between adjuvant therapy—especially tamoxifen—for a first breast cancer might predict features of contralateral breast cancer, and what implications these relationships have for tumor initiation, progression, treatment, and prevention strategies.
Decreasing Anxiety After Abnormal Mammograms
Few studies have evaluated interventions to decrease a woman’s anxiety after she receives an abnormal mammogram (i.e., one with a recommendation for follow-up). Barton et al. (p. 529) performed a controlled trial to compare the effects of immediate reading of mammograms (radiology intervention), of an educational intervention that taught skills to cope with anxiety, both interventions, or no intervention on the psychological status of women aged 39 years or older whose mammograms were normal or abnormal. The authors analyzed psychological status 3 weeks and 3 months after the mammograms. Based on their findings, the authors conclude that immediate reading of screening mammograms, but not an educational intervention that targets coping skills, was associated with less anxiety among women with false-positive mammograms 3 weeks after mammography.
Caloric Restriction and Breast Cancer Risk
Data from animal models suggest that caloric restriction may reduce the risk of breast cancer. Elias et al. (p. 539) examined whether caloric restriction imposed as a consequence of the 1944–1945 Dutch famine was associated with a reduced risk of breast cancer in women participating in a Dutch breast cancer screening program. The authors found that, compared with women who were not exposed to the famine, the risk of breast cancer was increased in women who were severely exposed. The association between famine exposure and breast cancer risk was stronger for women who were exposed between the ages of 2 and 9 years than for women who were exposed at older ages. The authors conclude that the risk of breast cancer was increased in women who were exposed to a short but severe famine decades earlier and note that this result is compatible with data from the few animal studies investigating effects of short-term, transient caloric restriction.
Aspirin Use and Pancreatic Cancer Mortality
Previous epidemiologic studies have reported mixed and limited results regarding aspirin use and pancreatic cancer risk. To determine whether there is an association between aspirin use and mortality from pancreatic cancer, Jacobs et al. (p. 524) investigated aspirin use in a cohort of 987,590 adults in the United States Cancer Prevention Study II. The participants completed a self-administered questionnaire in 1982 and were followed through 2000. During the follow-up period, 2,434 men and 2,143 women died from pancreatic cancer. The authors calculated rate ratios of pancreatic cancer mortality according to monthly aspirin use, and they found no association between aspirin use and pancreatic cancer mortality, even among participants who reported aspirin use equal to or greater than 30 times per month and had used aspirin for 20 or more years.
Plasma C-Peptide and Risk of Colorectal Cancer
Colorectal cancer and type 2 diabetes share many risk factors, and hyperinsulinemia appears to be associated with an increased risk of colorectal cancer. To determine whether insulin and insulin resistance are associated with the risk of developing colorectal cancer, Ma et al. (p. 546) used the plasma concentration of C-peptide (an indicator of insulin production) in 176 patients with colorectal cancer and 294 healthy control subjects in a nested case–control study in the Physicians’ Health Study. They found that elevated insulin production, as reflected by elevated concentrations of plasma C-peptide, may predict the risk of developing colorectal cancer, independently of body mass index, factors related to insulin resistance, or levels of insulin-like growth factor I and insulin-like growth factor binding protein 3.
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