Validation of Residual Cancer Burden as Prognostic Factor for Breast Cancer Patients After Neoadjuvant Therapy

• Published in: Annals of surgical oncology Vol. 26; no. 13; pp. 4274 - 4283
• Main Authors: Müller, Hannah Deborah, Posch, Florian, Suppan, Christoph, Bargfrieder, Ute, Gumpoldsberger, Melanie, Hammer, Robert, Hauser, Hubert, Dandachi, Nadia, Prein, Kurt, Stoeger, Herbert, Lax, Sigurd, Balic, Marija
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.12.2019; Springer Nature B.V
• Subjects: Anthracycline; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Biopsy; Breast cancer; Breast Neoplasms - drug therapy; Breast Neoplasms - pathology; Breast Oncology; ErbB-2 protein; Female; Follow-Up Studies; Humans; Mathematical models; Medicine; Medicine & Public Health; Middle Aged; Neoadjuvant Therapy - mortality; Neoplasm Recurrence, Local - drug therapy; Neoplasm Recurrence, Local - pathology; Neoplasm, Residual - drug therapy; Neoplasm, Residual - pathology; Oncology; Prognosis; Prospective Studies; Retrospective Studies; Statistical analysis; Surgery; Surgical Oncology; Survival; Survival Rate
• ISSN: 1068-9265; 1534-4681
• DOI: 10.1245/s10434-019-07741-w

Background Assessing the residual cancer burden (RCB) predictive performance, the potential subgroup effects, and time-dependent impact on breast cancer patients who underwent neoadjuvant therapy in a developer’s independent cohort is essential for its usage in clinical routine. Methods Between 2011 and 2016, the RCB scores of 184 female breast cancer patients were prospectively collected, and subsequent clinicopathological and follow-up data were obtained retrospectively. Recurrence-free survival (RFS), overall survival (OS), as well as subgroup analysis, and time-dependent variables were calculated with multivariate, complex, or linear statistical models. Results A total of 184 patients (HER2 33%, TNBC 27%), with a mean follow-up time of 4 years, treated with neoadjuvant systemic therapy (92% anthracycline-taxane based) were analyzed revealing 43 events (38 recurrences, 28 deaths). High RCB scores were associated with recurrence (median index: 2.34 vs. 1.39 points, rank-sum p  < 0.0001), decreased RFS (hazard ratio [HR] = 1.80, 95% confidence interval [CI] 1.44–2.24, p  < 0.0001) and reduced OS (HR 1.96, 95% CI 1.49–2.59, p  < 0.0001). The RCB score showed proportionality of hazards (interaction HR with linear follow-up time = 1.00, p  = 0.896) and good discriminating power (Harrell’s c index 0.7). Conclusions Our results confirm the RCB score as externally valid prognostic marker and being independent of molecular subtype for RFS and OS in a clinical setting.