TNMpBC-NeoBCSS model: A Breast Cancer Specific Survival Prediction Model for Triple-negative Metaplastic Breast Carcinoma Patients with Neoadjuvant Therapy

Background: The breast cancer specific survival (BCSS) benefits of Neoadjuvant therapy (NeoAT) for triple-negative metaplastic breast cancer (TNMpBC) was uncertain. This study aimed to develop a prediction model for assessing the BCSS for TNMpBC patients with NeoAT. Methods: The primary cohort of 1163 patients with TNMpBC, from which a nomogram was established based on the results of a LASSO regression analysis, was derived from multi-centers data in China and the SEER database. This model was further validated by an independent cohort of 155 TNMpBC patients with NeoAT, with discrimination and calibration assessed. Results: Totally 155 (13.3%) TNMpBC patients received NeoAT, with 45 (29.0%) cases demonstrating pathologic complete response (pCR),were enrolled. Subjects acquired pCR had superior BCSS. Four variables significantly associated with BCSS were incorporated in the establishment of model: age at diagnosis, T stage, N stage, and response to NeoAT. This model was well validated , with a C-index of 0.82, and area under the curves of 0.838, 0.866 in training cohort, respectively, for 3- years and 5-years BCSS. Based on the cutoff scores from the TNMpBC-NeoBCSS model and calculated by X-tile analysis, patients in high risk group had a inferior BCSS (HR=6.77, P< 0.0001 ) when compared with those in low-risk group. Conclusion: TNMpBC-NeoBCSS model provides a favorable tool for assessing the BCSS for the TNMpBC patients with NeoAT and may help doctors and TNMpBC patients optimally make decision on the necessity of neoadjuvant therapy on the basis of individual BCSS.