Is conservative surgery a good option for patients with "triple negative" breast cancer?

Abstract

Background: Triple negative breast cancers (negative estrogen receptor, progestagen receptor and no overexpression of HER2) seems to be more aggressive than other breast carcinoma subtypes. Therefore, it is necessary to analyze if a more aggressive surgical treatment should be offered to this subgroup of patients.

Patients and methods: The Castellon Cancer Registry Database (C.Valenciana, Spain) was used to identify eligible breast cancer patients. Female patients who were diagnosed and/or treated from January 2000 to December 2008 with primary, invasive, unilateral breast cancer at our hospital were included. A total of 410 patients make up the study population. Kaplan-Meier curves and log-rank tests were used to estimate 5-year local recurrence functions and to compare them across strata. Cox proportional hazards models were used to calculate hazard ratios and 95% confidence intervals to fit the effect of conservative surgery and other independent variables on local recurrence.

Results: Median follow-up time was 60 months (1-127 months). A total of 21 patients (5%) presented a local recurrence during follow-up. There was a 9% difference in terms of local recurrence between conservative and non-conservative techniques for triple negative patients, whereas such difference was only 1% for no triple negative patients. On univariate analysis for local recurrence, only tumor size and lymph node metastasis were statistically associated with local recurrence. All other variables (type of surgery, triple negative status, molecular classification, tumor grade, age, adjuvant treatments, and total number of analyzed lymph nodes) were not statistically significant. On multivariate analysis, independent prognostic factors were breast conservative surgery (HR 4.62 95%CI 1.12-16.82), number of positive lymph nodes (HR 1.07 95%CI 1.01-1.17) and millimetre tumor size (HR 1.02 95%CI 1.01-1.06). In contrast, triple negative status trended to be a risk factor but without statistical significance (HR 1.59 95%CI 0.42-8.04).

Conclusions: It was not possible to find statistically significant differences between conservative and non-conservative surgery for triple negative breast cancer. However, a trend was observed for higher recurrence rates after breast conservative surgery for this group of patients. Prospective clinical trials are needed to confirm this observation.