Prognostic Factors in Patients with Triple Negative Breast Cancer Undergoing Adjuvant Radiotherapy: A 10-Year Single Center Experience

Abstract

Background: Triple negative breast cancer (TNBC) is the most aggressive and worst prognosis group among breast cancer molecular subtypes. Determining the prognostic factors and parameters affecting survival in the TNBC group were aimed with this retrospective study.
 Methods: The patients were divided into two groups as TNBC and non-TNBC. Clinicopathological and treatment parameters of both groups were compared. Survival rates were evaluated using Kaplan Meirer method.
 Results: 110(11.1%) of 992 patients were triple negative. 2, 5 and 10-year overall survival (OS) was 91.8%, 75.8%, 64% and 98.5%, 91.3% and 76.2%, respectively in the TNBC and non-TNBC groups. Disease-free survival (DFS) was median 29.7 months in the TNBC group and 52.37 months in the non-TNBC group. The TNBC group has more grade 2-3 tumors (95.8% vs 87.8%, p=0.019), higher ki-67 value (72.7% vs 44.9%, p<0.001), more metastasis presence (28.2% vs 16.2%, p=0.002) and more exitus (28.2% vs 14.5%, p<0.001) than the non-TNBC group. It was not statistically significant as well as local recurrence was higher in the TNBC group. Brain metastasis was observed more frequently in the TNBC group. In the TNBC group, being ≥70 years of age (p=0.05), having T3-4 disease (p=0.040), presence of PNI (p=0.022), presence of metastasis (p<0.001), presence of brain metastasis (p=0.049) had a negative effect on OS in univariate analysis.
 Conclusion: Shorter OS and DFS were found in the TNBC group similar to previous studies. Since hormonal treatment cannot be used in this group, individualization of treatments gains importance by knowing the prognostic factors.