The CancerWeb Report, What's New In Cancer: March, 1996
Breast Cancer

• Prognostic markers - Many markers have been suggested as guides to prognosis. Two of them, called Ki-67 and S-phase fraction, are directly related to rates of cell division. In a study from Methodist Hospital, Houston, and Texas Health Center, San Antonio, cases with high Ki-67 had significantly shorter disease- free survival and an almost two-fold increased risk for recurrence of disease. Ki-67 may be a significant indicator of prognosis independent of S-phase and tumor size. (Brown, Clin Cancer Res 2:585, 1996)

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• Breast-conserving surgery - Fifteen-year results of breast- conserving surgery and irradiation were reported for intraductal breast cancers in 268 women from US and Europe followed for a mean time of over ten years. Overall survival at 15 years was 87% and survival when only breast cancer was figured in was 96%, as was metastasis-free survival. The local failure rate was 19% and median time to failure was about 5 years. (Solin, J Clin Oncol 14:754, 1996)

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• Hormone replacement therapy in women with breast cancer - Do the risks of hormone replacement therapy in women with breast cancer outweigh the benefits? This was the question asked by a group at the University of Toronto. Using literature searches, and reports published up to March 1995, they found none of five meta- analyses demonstrated any significantly increased risk of developing breast cancer in those who had ever used estrogen or estrogen/progesterone replacement therapy compared with those who had never used them. Current users showed a small increase in risk, which should be balanced against the known cardiovascular and bone metabolism benefits and the relief of sometimes debilitating symptoms. (Roy, J Clin Oncol 14:997, 1996)

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• Milk protective against breast cancer? -A Finnish study detected a significant inverse relationship between milk consumption and risk of breast cancer with a risk ratio of 0.42 comparing the 25% highest and the 25% lowest milk consumption; there was no relationship for other dairy products. The association held even after allowances were made for smoking, body-mass index, childbirth, occupation, geographic area, or intake of other classes of foods and nutrients. The mechanism for the protective effect is unknown; the authors discussed such potential factors as calcium intake, lactic acid generating bacteria, and conjugated linoleic acid isomer. (Knekt, British Journal of Cancer 73:687, 1996)

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• Vegetables, fruit and other nutrients and breast cancer - A case- control study from the State University of New York in Buffalo, examined a whole range of foods and nutrients consumed over a two-year period by 297 premenopausal women aged 40 or over, and matched controls. There was a reduction in risk of breast cancer associated with high total intake of vitamin C, alpha-tocopherol, folic acid, alpha- and beta-carotene, lutein plus zeaxanthin, and dietary fiber from vegetables and fruits. Fruits were weakly associated with reduced risk. There was a strong relation between high vegetable intake and lowered risk, which was independent of intake of vitamin C, alpha-tocopherol, alpha- carotene, fiber, and folic acid. However, there was no association between intake of vitamins C and E and folic acid taken as supplements, a finding emerging from many other studies. It appears that no single dietary factor, but rather a synergistic interplay of components, identified and unidentified, affect breast cancer risk. (Freudenheim, Journal of the National Cancer Institute 88:340, 1996)

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• Family history and risk factors for breast cancer - Early first pregnancy is generally considered a protective factor in breast cancer, although there is an initial increase in risk. Those women with a family history of breast cancer are at higher overall risk of contracting the disease. The results of the Nurses' Health Study, reported this month, indicated that in those women with a mother or sister history of breast cancer, first pregnancy always exacerbated their breast cancer risk no matter at what age pregnancy had occurred. The adverse effect of the first pregnancy persisted through age 70. Women without a family history of the disease, had only a small increase in risk with first pregnancy, and decreased risk if the pregnancy were early, and also if there were a higher number of births. (Colditz, Journal National Cancer Institute 88:365, 1996)