De-novo metastatic breast cancers with or without primary tumor resection - A 10-year study

Treatment of de novo metastatic breast cancer is usually palliative with systemic treatment; surgical excision of the primary tumour is reserved in patients with significant symptoms from the primary tumour. Survival benefit of surgical removal of the primary tumour remains controversial.

All patients treated with de novo metastatic breast cancer (MBC) between 2007 and 2016 were retrieved from a prospectively-maintained database. Demographic and tumour characteristics were compared. Overall survival (OS) was analysed using Kaplan-Meier Method and log rank tests. Multivariate analysis was performed to evaluate the prognosticators of OS in de novo MBC.

Median age of diagnosis was 53 years old (Range 24-91 years old). 91 patients received resection of the primary tumour, including 86 mastectomies and 5 breast conserving surgeries (surgical group). 81 patients were never treated surgically (non-surgical group). Baseline demographic data were comparable apart from being younger age in the surgical group. 5-year OS in surgical group was significantly better than non-surgical group (43.9% vs. 33.9%, p = 0.026). Multivariate analysis found that advanced age (Hazard ratio: 1.034, p = 0.005, 95% CI 1.010-1.058) and presence of visceral metastasis (Hazard ratio: 1.672, p = 0.038, 95% CI 1.028-2.719) were significant adverse prognosticators through multivariate analysis; while positive oestrogen receptor (ER) status was the only positive prognosticator in the analysis (Hazard ratio: 0.42, p = 0.001, 95% CI 0.256-0.688).

Surgical excision of primary breast tumour may confer survival benefit in de novo MBC.