305P - Prognosis of isolated locoregional recurrence after early breast cancer with immediate breast reconstruction surgery: A retrospective multi-institutional study

Background

The prognosis in patients with breast cancer with isolated locoregional recurrence (ILRR) without simultaneous distant metastases after immediate breast reconstruction (IBR) remains unknown. We aimed to investigate the prognosis in this patient population.

Methods

This multi-institutional retrospective observational study evaluated 3,295 patients with primary breast cancer who underwent IBR at 12 Japanese medical facilities between January 1, 2008 and December 31, 2016. The outcome measures were the prognostic factors for ILRR after IBR, 5-year distant metastasis-free survival (DMFS), and 5-year overall survival (OS).

Results

Mastectomy or skin-sparing mastectomy was performed in 3,295 patients. ILRR occurred in 70 patients, and the median observation period from ILRR diagnosis was 39.3 months. Of the 70 patients, 9 (12.9%) had axillary lymph node recurrence (ALNR) at the time of ILRR diagnosis. The 5-year DMFS after ILRR was 92.4%. Patients with ILRR who had ALNR had a significantly worse DMFS than that had by those without ALNR (P = 0.005).The 5-year OS after ILRR was 91.2%. Patients with ILRR who had ALNR had a significantly worse OS than that had by those without ALNR (P = 0.005).The relationship between DMFS and clinicopathological factors was analyzed using the Cox proportional hazards model. Univariate analysis revealed significant associations of pN at primary surgery (P = 0.041) and ALNR at ILRR (HR: 9.960, 95% CI: 1.400–70.862, P = 0.022) with DMFS. However, ALNR was the only independent prognostic factor for DMFS in the multivariate analysis (P = 0.041). Univariate analysis revealed significant associations of post-mastectomy radiation therapy (PMRT) at primary surgery (P = 0.023) and ALNR at ILRR (P = 0.043) with OS. In multivariate analysis, both PMRT (P = 0.010) and ALNR (P = 0.028) were independent prognostic factors for OS.

Conclusions

Although patients with breast cancer who have ILRR after IBR have a favorable prognosis overall, ALNR at the diagnosis of ILRR may be a poor prognostic factor. Our results may contribute to developing strategies to predict prognosis in patients with breast cancer who develop ILRR after IBR.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Collaborative Study Group of Scientific Research of the Japanese Breast Cancer Society.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.