Effects of radiotherapy and surgery in early breast cancer: an overview of the randomized trials

Background Randomized trials of radiotherapy and surgery for early breast cancer may have been too small to detect differences in long-term survival and recurrence reliably. We therefore performed a systematic overview (meta-analysis) of the results of such trials. Methods Information was sought on each subject from investigators who conducted trials that began before 1985 and that compared local therapies for early breast cancer. Data on mortality were available from 36 trials comparing radiotherapy plus surgery with the same type of surgery alone, 10 comparing more-extensive surgery with less-extensive surgery, and 18 comparing more-extensive surgery with less-extensive surgery plus radiotherapy. Information on mortality was available for 28,405 women (97.4 percent of the 29,175 women in the trials). Results The addition of radiotherapy to surgery resulted in a rate of local recurrence that was three times lower than the rate with surgery alone, but there was no significant difference in 10-year survival; among a total of 17,273 women enrolled in such trials, mortality was 40.3 percent with radiotherapy and 41.4 percent without radiotherapy (P = 0.3). Radiotherapy was associated with a reduced risk of death due to breast cancer (odds ratio, 0.94; 95 percent confidence interval, 0.88 to 1.00; P = 0.03), which indicates that, after 10 years, there would be about 0 to 5 fewer deaths due to breast cancer per 100 women. However, there was an increased risk of death from other causes (odds ratio, 1.24; 95 percent confidence interval, 1.09 to 1.42; P = 0.002). This, together with the age-specific death rates, implies, after 10 years, a few extra deaths not due to breast cancer per 100 older women or per 1000 younger women. During the first decade or two after diagnosis, the excess in the rate of such deaths that was associated with radiotherapy was much greater among women who were over 60 years of age at randomization (15.3 percent vs. 11.1 percent [339 vs. 249 deaths]) than among those under 50 (2.5 percent vs. 2.0 percent [62 vs. 49 deaths]). Breast-conserving surgery involved some risk of recurrence in the remaining tissue, but no significant differences in overall survival at 10 years were found in the studies of mastectomy versus breast-conserving surgery plus radiotherapy (4891 women), more-extensive surgery versus less-extensive surgery (4818 women), or axillary clearance versus radiotherapy as adjuncts to mastectomy (4370 women). Conclusions Some of the local therapies for breast cancer had substantially different effects on the rates of local recurrence — such as the reduced recurrence with the addition of radiotherapy to surgery — but there were no definite differences in overall survival at 10 years

Parity in relation to survival following breast cancer

Aim: The present study examines the association between parity and survival following breast cancer diagnosis. Methods: Medical records of 4453 women diagnosed with breast cancer in Malmö, Sweden, between 1961 and 1991 were analysed. All women were followed until 31 December 2003, using the Swedish Cause-of-Death Registry. Breast cancer specific mortality rate was calculated in different levels of parity. Corresponding relative risks, with 95% confidence intervals (CI), were obtained using Cox's proportional hazards analysis. All analyses were adjusted for potential prognostic factors and stratified for age, menopausal status and diagnostic period. Results: As compared to women with one child, nulliparity (RR 1.27: 95% CI 1.09-1.47), and high parity (four or more children) (1.49: 1.20-1.85) were positively associated with a high mortality from breast cancer. When adjusted for potential confounders, the association was only statistically significant for high parity (1.33: 1.07-1.66). In the analyses stratified on age and menopausal status, there was a similar positive association between high parity and breast cancer death in all strata, although only statistically significant among women older than 45 years of age or postmenopausal. Nulliparity was associated with breast cancer death in women that were younger than 45 years of age (1.28: 0.79-2.09) or premenopausal (1.30: 0.95-1.80), but these associations did not reach statistical significance. There was no association between nulliparity and breast cancer death in women older than 45 years of age or postmenopausal. All associations were similar in analyses stratified for diagnostic period. Conclusion: Women with four or more children have a poor breast cancer survival as compared to women with one child. © 2008 Elsevier Ltd. All rights reserved