Disease recurrence and survival in patients with multifocal breast cancer: a follow-up study with 7-year results

Background: Few studies have shown that multifocal breast cancer (MBC) has poorer outcomes compared with unifocal breast cancer (UBC). Currently, there is no long-term data on disease recurrence and survival in patients with MBC. The aim of this study is to evaluate whether patients with MBC have worse outcomes compared with UBC in respect to disease recurrence and survival. Methods: This is a retrospective study of patients diagnosed with stage I-III MBC from 2000 to 2007 in comparison with UBC with a median follow-up of 7 years. Prognostic factors were prospectively collected from the breast cancer unit database. Univariate and multivariable analyses for disease recurrence and survival were performed as well as Kaplan-Meier curves. Results: A total of 152 patients were included; 75 with MBC, 77 with UBC. The multifocal group was treated more aggressively with mastectomy (73% versus 25%, P < 0.0001) and chemotherapy (53% versus 42%). Breast cancer recurred in nine (11.7%) patients in the UBC group and nine (12%) patients in the MBC group respectively (hazard ratio (HR): 1.13, 95% confidence interval (CI): 0.45-2.86, P = 0.794). There were 10 (13%) mortalities in the unifocal group as compared with 11 (14.7%) in the multifocal group (HR: 1.02, 95% CI: 0.42-2.48, P = 0.969). There were no statistically significant differences in the all-cause mortality and disease recurrence rates between both groups. Discussion: There were no statistically significant differences in disease recurrence or mortality rates between MBC and UBC at a median follow-up of 7 years. However, patients in the MBC group received more aggressive treatment than the unifocal group.