|
Journal of Clinical Oncology, 2007 ASCO Annual Meeting Proceedings (Post-Meeting Edition).
Vol 25, No 18S (June 20 Supplement), 2007: 519
© 2007 American Society of Clinical Oncology
Comparison of survival rates in carcinoma in situ of the breast treated with total mastectomy to breast-conserving surgery and radiotherapy
M. N. Ibrahim,
Z. Abdullah,
L. Healy,
C. Murphy,
I. Y. Yousif and
M. J. Martin
Sligo General Hospital, Sligo, Ireland
519
Background: Carcinoma in situ (CIS) of the breast is a precancerous lesion with the potential to progress to invasive cancer. In 2003, CIS accounted for 19% of all newly diagnosed invasive and non-invasive breast lesions combined in the United States. Current treatment options are mastectomy ± tamoxifen, and breast-conserving surgery with radiotherapy ± tamoxifen. As there are no randomized comparisons of these 2 treatments, data from the Surveillance Epidemiology and End Results (SEER) database was used to compare their survival rates. Methods: 88,285 patients were identified with CIS from 1988 - 2003. Of these, 27,728 patients were treated with a total mastectomy, and 25,240 patients received breast-conserving surgery with radiotherapy. Kaplan-Meier survival analyses and Cox proportional hazards regression were used to compare overall survival and disease specific survival at 5 and 10 years. Results: Kaplan-Meier analyses demonstrated 5 year overall survival rates for total mastectomy vs. breast conserving surgery with radiotherapy of 95.46% vs. 97.59% respectively (Log-rank P < 0.0001). The 5 year rates for disease specific survival were 99.16% vs. 99.72% respectively (Log-rank P < 0.0001). At 10 years the overall survival rates had fallen to 91.96% vs. 96.09% respectively (Log-rank P < 0.0001). The 10 year disease specific survival rates were 98.61% vs. 99.50% respectively (Log-rank P < 0.0001). Cox proportional hazards regression demonstrated a relative risk of 0.847 (95% confidence interval (CI) 0.790 - 0.907) and 1.110 (95% CI 0.931 - 1.324) for 5 year overall survival and disease specific survival respectively, when total mastectomy was compared with breast conserving surgery and radiotherapy. At 10 years, the relative risks were 0.865 (95% CI 0.820 - 0.913) and 1.035 (95% CI 0.900 - 1.190) for overall survival and disease specific survival respectively. Conclusions: Overall, when looking at disease-specific survival rates by multi-variate analysis, there does not appear to be a significant difference between total mastectomy and breast-conserving surgery with radiotherapy in the treatment of CIS.
No significant financial relationships to disclose.
Abstract presentation from the 2007 ASCO Annual Meeting
|