WITHDRAWN: Radiotherapy for early breast cancer.

Wednesday, 27/03/2013  |   Breast Cancer  |  no comments

This Cochrane review of radiation in breast cancer deserves more attention and should be given to women, especially young women, contemplating radiotherapy. The last paragraph says it all; radiotherapy does reduce recurrence and there is benefit for older women in survival rates but there are limits to survival due to hazards in younger women. WITHDRAWN: Radiotherapy for early breast cancer. Cochrane Database Syst Rev. 2008 Oct 8;(4):CD003647. The long-term effects of radiotherapy on mortality from breast cancer and other causes remain uncertain. In this report the Early Breast Cancer Trialists’ Collaborative Group present their systematic overview of treatment with radiotherapy. A meta-analysis was done of 10-year and 20-year results from 40 unconfounded randomised trials of radiotherapy for early breast cancer. Radiotherapy fields generally included not only chest wall (or breast) but also axillary, supraclavicular, and internal mammary nodes. Data collection involved central review of individual patient data on recurrence and cause-specific mortality from 20,000 women.   A reduction of approximately two-thirds in local recurrence was seen in all trials, largely independent of the type of patient or type of radiotherapy (8.8% vs 27.2% local recurrence by year 10). Hence, to assess effects on breast cancer mortality of substantially better local control, results from all trials were combined. Breast cancer mortality was reduced (2p=0.0001) but other, particularly vascular, mortality was increased (2p=0.0003), and overall 20-year survival was 37.1% with radiotherapy versus 35.9% control (2p=0.06). There was little effect on early deaths, but logrank analyses of later deaths indicate that, on average after year 2, radiotherapy reduced annual mortality rates from breast cancer by 13.2% (SE 2.5) but increased those from other causes by 21.2% (SE 5.4). Nodal status, age, and decade of follow-up strongly affected the ratio of breast cancer mortality to other mortality, and hence affected the ratio of absolute benefit to absolute hazard from these proportional changes in mortality.   Radiotherapy regimens able to produce the two-thirds reduction in local recurrence seen in these trials, but without long-term hazard, would be expected to produce an absolute increase in 20-year survival of about 2-4% (except for women at particularly low risk of local recurrence). The average hazard seen in these trials would, however, reduce this 20-year survival benefit in young women and reverse it in older women.   Analysis of cardiac and pulmonary complication probabilities after radiation therapy for patients with early-stage breast cancer. Utehina O, Popovs S, Purina D, et al. Medicina (Kaunas). 2009;45(4):276-85. The purpose of this study was to evaluate the radiobiological implications of clinical use of respiratory-gated techniques for postoperative radiation therapy of early-stage left-sided breast cancer after breast-conserving surgery. Radiation therapy treatment plans of 80 patients with early-stage breast cancer (stage I-II), receiving whole breast irradiation after breast-conserving therapy, were analyzed. The control group consisting of 47 patients received standard radiation therapy, and the respiratory-gated group consisting of 33 patients received deep inspiration-gated radiation therapy. Normal tissue complication probabilities (NTCP) for cardiac mortality and for clinical radiation-induced pneumonitis were calculated for all patients included in present study, using relative seriality model. NTCP data were analyzed for 113 radiation therapy plans, which included free breathing plans for the respiratory-gated groups.   Pneumonitis probability was 0.6% (range 0.0-2.8%) and 0.3% (0.0-1.2%) for control and respiratory-gated group, respectively. Cardiac mortality was 1.3% (0.0-5.0%) and 0.2% (0.0-2.8%) for control and respiratory-gated group, respectively. Using respiratory-gated radiation therapy, NTCP was reduced in comparison with the control group by 83% (P<0.00001) and by 55% (P=0.01270) for cardiac mortality and for clinical radiation-induced pneumonitis, respectively.   Use

of respiratory-gated radiation therapy, for postoperative treatment of early-stage breast cancer, significantly reduces excessive cardiac mortality probability and pulmonary complication probability, as compared to standard radiation therapy techniques. This is especially important from heart complication probability point of view, as cardiac mortality remains one of the important issues of postoperative breast irradiation in patients with early stage breast cancer.

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