Are Changes in PET/CT SUVmax Associated with Pathologic Complete Response in Breast Cancer Patients Receiving Neoadjuvant Therapy?

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Dursun B., YAŞAR H. A., SOYDAL Ç., Demirkazık A.

Acta Haematologica Oncologica Turcica, cilt.59, sa.1, ss.27-31, 2026 (Scopus)

Özet

Aim: Non-invasive predictors of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) are needed in breast cancer (BC). We evaluated whether serial fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) maximum standardized uptake value (SUVmax ) metrics [baseline, preoperative, and the percentage change of SUVmax (ΔSUVmax %)] and complete metabolic response (CMR) are associated with pCR. Methods: This retrospective single-center cohort included patients treated with NAC followed by surgery who underwent paired baseline and preoperative18F-FDG PET/CT. Primary tumor SUVmax was recorded on both scans, ΔSUVmax % was calculated, and CMR was defined as complete resolution of pathologic FDG uptake on the preoperative scan. pCR was defined as ypT0/is ypN0. Results: Fifty-six patients were included (median age, 51.5 years). Subtypes were HR+/HER2-(50%), HER2+ (30.3%), and triple-negative BC (TNBC) (19.7%). Overall, pCR occurred in 25% (14/56) and CMR occurred in 35.7% (20/56). Baseline SUVmax differed by subtype (highest in TNBC), and pCR rates varied significantly (lowest in luminal, highest in HER2+). Compared with the non-pCR group, the pCR group had lower preoperative SUVmax (0.68 vs 4.33; p=0.001) and higher ΔSUVmax % (95.89% vs 54.10%; p=0.001). In univariate logistic regression, lower preoperative SUVmax [odds ratio (OR): 0.64; p=0.04]., higher ΔSUVmax % (OR: 1.06 per 1% increase; p=0.01), and CMR (OR: 6.75; p=0.01) were associated with pCR. Conclusion: In this retrospective cohort, end-of-NAC18F-FDG PET/CT findings—especially a low preoperative SUVmax and CMR—were associated with a higher likelihood of pCR while ΔSUVmax % contributed incremental predictive signal.