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

• Docetaxel, a new drug for breast cancer - The activity of docetaxel used as a single agent is comparable to that of many combination regimens used in breast cancer, according to researchers from the National Cancer Institute of Canada's Clinical Trials Group. They reported 22 partial remissions and four complete responses among 47 assessable patients. Starting doses were kept at 75 mg/m2 for the last 16 patients to reduce side effects; there was a 40% response rate at that dose. For 100 mg/m2 the response rate was 63%. Allergic hypersensitivity reactions occurred in 62%, and 21% had fever associated with severely reduced granulocyte levels. (Trudeau J Clin Oncol 14:422, 1996)

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• p53 and prognosis, a better test? - Alterations in the p53 gene appear to be good indicators of a worse prognosis, one which would justify more intensive adjuvant therapy. The test used for abnormal p53 should be as specific as possible. An article by researchers at the University of Uppsala, Sweden, in the Journal of the National Cancer Institute compared two different methods, one based on use of the mouse monoclonal antibody Pab 1801 (IHC) which measures total p53, the other actually screening the base sequences in the coding region of p53 for mutations, using reverse transcription, the polymerase chain reaction, and sequencing of the DNA (cDNA). Of the 316 tumors tested, 22% had p53 mutations determined by the cDNA method, while IHC indicated that 20% had elevated p53 levels, suggesting mutations. However, IHC failed to detect 33% of the mutations seen in cDNA, while 30% of the IHC-positive tumors were negative when sequences were examined by cDNA. Five-year survival estimates were significantly shorter for patients with p53 sequence-positive tumors than for those with sequence negative disease. In IHC- positive tumors, survival was shorter but without statistical significance. The sequence method was a better predictor and avoided the false positives and negatives of IHC. (Sjogren, J National Cancer Institute 88:173, 1996)

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• Effect of age on prognosis - Cancers do tend to grow differently in older than in younger women, and a study from the University of Nijmegen in the Netherlands, looked at this phenomenon. They studied women in three age groups: 40-49; 50-69; and over 70 years at diagnosis. Women with breast tumors of 1 cm or less in size survived longer than those with tumors larger than 2 cm in all age groups, but those in the under 50 group with tumors of 1.5 cm diameter or less had poorer survival than those in the older groups with tumors of about the same size. Early diagnosis may only improve survival in women under 50 if their cancers are less than 1 cm in size. This obviously impacts on the controversy over whether frequent mammography benefits younger women, by emphasizing the importance of finding very small tumors. (Peer, British Journal Cancer 73:382, 1996)

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• Fat intake and risk of breast cancer - Basing their findings on 4,980 cases from among 337,819 women taking part in seven prospective studies in four countries, epidemiologists concluded that there was no evidence of an association between total dietary fat intake and the risk of developing breast cancer. The association of fat intake and breast cancer looked very strong in the 1970s, but data based on national per capita fat consumption and national incidence rates, as most were, can be misleading. Recent studies relying on more direct dietary information, such as a large case-control study of over 2,000 women, tend to point in the direction of no relationship, as does this multinational one. The issue is not closed, but it looks as if it might be soon. (Hunter, New England Journal of Medicine 334:356, 1996)