Breast-Conserving Surgery Vs Mastectomy in Early-Stage Breast Cancer

A systematic review 1 including 6 studies with a total of 3865 subjects was abstracted in DARE.

Overall 10-year survival was similar in both treatments. Survival rates appear slightly higher among patients treated with breast-conserving surgery (BCS) but the differences are not significant. The pooled odds ratios were 0.90 (95% CI 0.74 to 1.09) and 0.91 (0.78 to 1.05) at 5 and 10 years, respectively.

A meta-analysis 2 assessing overall survival (OS) included 6 trials with a total of 22 598 patients 40 years old or younger with early T1-T2 N0-N + M0 breast cancer. 10898 patients underwent BCS plus whole breast radiotherapy and 11700 underwent mastectomy. No difference in risk of death was found between the two groups (10% not significant risk reduction in patients who underwent BCS compared to mastectomy) HR 0.90; 95% CI 0.81 to 1.00).

A population-based study 3.evaluated 10 year survival of 37 207 patients after BCS plus radiotherapy vs mastectomy. Primary outcomes were 10 year overall survival in the entire cohort and breast cancer-specific survival in a representative subcohort of patients diagnosed in 2003 with characteristics similar to the entire cohort. In the 2003 subcohort 62% received BCS plus radiotherapy and 38% received mastectomy. BCS plus radiotherapy was significantly associated with improved 10 year overall survival in the whole cohort overall compared with mastectomy: adjusted HR 0.81, 95% CI 0.78 to 0.85; p<0·0001, and this improvement remained significant for all subgroups of different T and N stages of breast cancer. BCS plus radiotherapy did not significantly improve 10 year distant metastasis-free survival in the 2003 cohort overall compared with mastectomy (adjusted HR 0.88. 95% CI 0.77 to 1.01; p=0.7), but did in the T1N0 subgroup.

References

• Morris AD, Morris RD, Wilson JF, White J, Steinberg S, Okunieff P, Arriagada R, Lê MG, Blichert-Toft M, van Dongen JA. Breast-conserving therapy vs mastectomy in early-stage breast cancer: a meta-analysis of 10-year survival. Cancer J Sci Am 1997 Jan-Feb;3(1):6-12. [PubMed] [DARE]
• Vila J, Gandini S, Gentilini O. Overall survival according to type of surgery in young (=40 years) early breast cancer patients: A systematic meta-analysis comparing breast-conserving surgery versus mastectomy. Breast 2015;24(3):175-81. [PubMed]
• van Maaren MC, de Munck L, de Bock GH et al. 10 year survival after breast-conserving surgery plus radiotherapy compared with mastectomy in early breast cancer in the Netherlands: a population-based study. Lancet Oncol 2016;17(8):1158-1170. [PubMed]