Pathological complete response and associated factors in breast cancer after neoadjuvant chemotherapy: A retrospective study
Adnan Gündoğdu1
, Mehmet Uluşahin1, Arif Burak Çekiç1, Seher Nazlı Kazaz2,3, Ali Güner1,4
1Department of General Surgery, Karadeniz Technical University Faculty of Medicine, Trabzon, Türkiye
2Department of Medical Oncology, Karadeniz Technical University Faculty of Medicine, Trabzon, Türkiye
3Clinic of Medical Oncology, Medical Park Trabzon Karadeniz Hospital, Trabzon, Türkiye
4Department of Biostatistics and Medical Informatics, Karadeniz Technical University Institute of Medical Science, Trabzon, Türkiye
Abstract
Objective: This study aimed to determine clinical and pathological factors that identify a pathological complete response (pCR) in breast cancer patients undergoing neoadjuvant chemotherapy (NAC).
Material and Methods: A retrospective, single-center study was conducted in women over the age of 18 who had been diagnosed with pathologically confirmed invasive breast cancer and who had received NAC between July 2016 and October 2021. Patient demographics, clinical, radiological, treatment, and pathological data were reviewed from the electronic hospital records. The primary outcome of interest was pCR, defined as the absence of residual invasive breast cancer in both the breast and axillary lymph nodes. Multivariable logistic regression analysis was used to identify factors associated with pCR.
Results: A total of 119 patients were included in the analysis. The distribution of age was 54.5 ± 11.5 years. pCR was observed in 33 (27.7%) patients. pCR for breast tissue was observed in 43 (36.1%) patients. There was no statistically significant relation between the clinical stage and pCR. Age, age at first labor, extent of disease in the breast, NAC completeness, clinical tumor size (cT) stage, clinical lymph node (cN) stage, and molecular subtype were analyzed in a multivariable model. Analysis showed that molecular subtype was the only independent factor related to pCR. pCR rates across molecular subtypes were: 8.7% in luminal-A, 10.8% in luminal-B, 54.5% in human epidermal growth factor receptor 2 (HER-2)-positive, 42.4% in luminal-B (HER-2 positive) and 46.7% in triple-negative. There was no statistically significant difference between luminal-A and luminal-B subgroups (odds ratio 1.15, 95% confidence interval, 0.19-9.35, p= 0.881). Despite the limited number of patients in HER2-positive and triple-negative groups, both demonstrated statistically significant higher odds compared to reference group.
Conclusion: The presented study underscores the relevance of molecular subtypes in determining the response to neoadjuvant chemotherapy in breast cancer patients. Particularly HER2-positive and triple-negative subtypes may demonstrate more favorable response rates.
Keywords: Breast cancer, neoadjuvant chemotherapy, pathological complete response, molecular subtypes
Cite this article as: Gündoğdu A, Uluşahin M, Çekiç AB, Kazaz SN, Güner A. Pathological complete response and associated factors in breast cancer after neoadjuvant chemotherapy: A retrospective study. Turk J Surg 2024; 40 (1): 73-81.
This study was approved by Karadeniz Technical University Faculty of Medicine Scientific Research Ethics Committee (Decision date: 01.02.2022, No: 24237859-51).
Externally peer-reviewed.
Concept - All of authors; Design - All of authors; Supervision - AG, AG; Data Collection and/or Processing - AG, AG; Analysis and/or Interpretation - All of authors; Literature Search - AG, MU, AG; Writing Manuscript - AG, AG; Critical Reviews - All of authors.
The authors have no conflicts of interest to declare.
The authors declared that this study has received no financial support.