Introduction: To evaluate the predictive significance of pretreatment metabolic tumor volume on pathologic response in patients who received neoadjuvant chemotherapy for breast cancer.
Methods: Seventy patients who received neoadjuvant chemotherapy between 2013 and 2017 years were enrolled in the study. Pathologic responses and 18-fluorodeoxyglucose positron emission tomography/computed tomography metabolic dates of patients were obtained from archive files.
Results: Forty-six (65.7%) patients were in stage II and 24 (34.3%) patients were in stage III; 25 (35.7%) patients were human epidermal growth factor receptor 2 positive, 46 (65.7%) patients were estrogen receptor-positive, 26 (37.1%) patients were progesterone receptor-positive. According to the Miller-Payne grading system, 24 (34.3%) patients constituted 100% pathological response; patients with 91-99% pathological response were 12 (17.1%), the number of patients with non-pathologic response was 6 (8.6%). Median metabolic tumor volume was 7.3 cm3 (7.1 ± 3.5), 8.8 (11.4 ± 9.4), 7.7 (8.3 ± 4.6) and 22 cm3 (19.8 ± 11.0) in patients with stages IIA, IIB, IIIA, and IIIB, respectively (p = 0.032). In Miller-Payne grading, the median metabolic tumor volume value was higher in patients with no pathologic response group than 100% response group (p = 0.003). The cut-off metabolic tumor volume value determining no pathologic response was calculated as higher than 13.62 cm3 (sensitivity 83.3% and specificity 82.8%).
Conclusions: Our study results suggest that higher pretreatment metabolic tumor volume values are predictive on no pathologic response in patients treated with neoadjuvant chemotherapy for breast cancer.
Keywords: Breast cancer; metabolic tumor volume; neoadjuvant chemotherapy; pathologic response.