Clinicopathological Characteristics and Treatment Strategies of Triple-Negative Breast Cancer Patients With a Survival Longer than 5 Years

Abstract

Purpose: Triple-negative breast cancer (TNBC) is characterized by high malignancy and a poor prognosis. Patients with TNBC who survive longer than 5 years represent a unique portion of the population. This study aimed to analyze the clinicopathological features, explore prognostic factors, and evaluate treatment options for these patients.

Methods: A total of 24,943 TNBC patients were enrolled from the national Surveillance, Epidemiology, and End Results (SEER) database between January 2010 and December 2016. The patients were divided into three groups: group 1, survival time <3 years; group 2, 3-5 years; and group 3, survival time ≥5 years. The overall survival (OS) and breast cancer cause-specific survival (BCSS) were primarily assessed in this study. A propensity score analysis was used to avoid bias caused by the data selection criteria. We used a Cox hazard ratio analysis to determine prognostic factors, which were selected as nomogram parameters to develop a model for predicting patient survival.

Results: Patients who survived longer than 5 years were more likely to be younger than 55 years, Caucasian, and exhibit a lower AJCC stage, N stage, distant metastasis, lymph node (LN) involvement, and tumor size than those with a shorter survival time (p < 0.05). The multivariable Cox regression analysis showed that age, race, tumor size, LN status, and chemotherapy were independent prognostic factors. Subgroup analyses for patients with tumors ≤20 mm displayed a superior OS and BCSS for breast-conserving surgery (BCS) not treated with a mastectomy. BCS provided at least an equivalent prognosis to a mastectomy in patients with tumors larger than 20 mm. A nomogram with a C-index of 0.776 (95% confidence interval: 0.767-0.785) was developed to predict the 3- and 5-year survival probability for the patients with TNBC.

Conclusion: A localized surgical approach may represent a superior choice for TNBC patients with a survival time longer than 5 years. Our study indicated that age, race, tumor size, LN status, and chemotherapy were independent prognostic factors. A prognostic nomogram directly quantified patient risk and was better able to predict long-term survival in TNBC patients.

Keywords: SEER database; breast cancer cause-specific survival; clinicopathological characteristics; overall survival; triple negative breast cancer.

Figure 1

Multivariable Cox regression analysis of the factors associated with OS and BCSS in patients with a survival time longer than 5 years. OS, overall survival; BCSS, breast cancer cause-specific survival.

Figure 2

The OS and BCSS of the different treatments. (A, B) Tumor size less than or equal to 20 mm. (C, D) tumor size greater than 20 mm. OS, overall survival; BCSS, breast cancer cause-specific survival.

Figure 3

The OS and BCSS of the different treatments after PSA matching. (A, B) tumor size less than or equal to 20 mm. (C, D) tumor size greater than 20 mm. OS, overall survival; BCSS, breast cancer cause-specific survival; PSA, propensity score analysis.

Figure 4

Subgroup analysis of different surgical approaches for stage I–III patients. (A) OS, (B) BCSS. OS, overall survival; BCSS, breast cancer cause-specific survival.

Figure 5

The OS of different surgical approaches stratified by LN status. (A) AJCC N0, (B) AJCC N1, (C) AJCC N2, and (D) AJCC N3. OS, overall survival; LN, lymph nodes.

Figure 6

A nomogram was used to predict the 3- to 5-year survival probability for patients with TNBC. LN, lymph nodes; TNBC, triple-negative breast cancer.

Figure 7

Validation of the nomogram. ROC curves and calibration plots for predicting patient survival at the 5-year time point in the training (A, B) and validation cohorts (C, D). ROC, receiver operating characteristic curve; AUC, areas under the ROC curve.