Evaluation of Clinical, Radiological, and Pathological Efficacy Regarding Neoadjuvant Chemotherapy in Breast Cancer

Objective:The aim of this study was to evaluate the radiological, clinical, and pathological responses before and after neoadjuvant chemotherapy (NAC) in patients with breast cancer, to examine the reliability of imaging modalities, and to compare treatment responses according to pathological subtypes. Materials and Methods:Forty breast cancer patients who underwent neoadjuvant chemotherapy followed by surgery between June 2020 and 2025 were retrospectively analyzed.Tumor diameters before and after treatment were measured using positron emission tomography-computed tomography (PET-CT).Axillary lymph node metastases were compared clinically, radiologically, and pathologically.In addition, treatment responses were analyzed according to pathological subtypes.Results: A significant reduction in tumor size was observed following NAC (p<0.001).Among the 20 patients who demonstrated a complete response on PET-CT, only 8 had a complete pathological response.The sensitivity, specificity, positive predictive value, and negative predictive value of PET-CT in detecting complete response were 100%, 62.5%, 40%, and 100%, respectively.A statistically significant downstaging after NAC was observed (p<0.001).Higher response rates were found in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative subtypes. Conclusion:Neoadjuvant chemotherapy significantly reduces tumor size and axillary involvement, enabling more conservative surgical approaches.Although PET-CT has high sensitivity in detecting complete response, its low positive predictive value highlights the need for complementary evaluation methods.Pathological subtypes are predictive of treatment response and should be taken into account during treatment planning.