Additional value of 18F-FDG PET/CT response evaluation in axillary nodes during neoadjuvant therapy for triple-negative and HER2-positive breast cancer

Abstract

Background 18F-FDG PET/CT can monitor metabolic activity in early breast cancer during neoadjuvant systemic therapy (NST), but it is unknown if the metabolic breast and axillary response differ. We evaluated the correlation between metabolic breast and axillary response at various time points during NST. Furthermore, we analysed if the combined metabolic response improves pathologic complete response (pCR) prediction compared to using the metabolic breast response alone.Methods 18F-FDG PET/CT was performed at baseline (PET1), 2–3 weeks (PET2), and 6–8 weeks (PET3) of NST in patients with triple-negative (TN) and HER2-positive node-positive breast cancer. SUVmax and ∆SUVmax were determined separately for breast and axilla. Spearman’s correlation coefficients (r) between both localisations were calculated. The accuracy of pCR total (ypT0/is,ypN0) prediction using the metabolic response in breast, axilla or both was examined using logistic regression analysis.ResultsHundred-five patients were included: 45 TN and 60 HER2-positive tumours. The metabolic response in breast and axilla correlated moderately in TN tumours (r = 0.57) using ∆SUVmax between PET1-PET3 and poorly in HER2-positive tumours (r = 0.49) using SUVmax at PET2. In TN tumours, metabolic breast response predicted pCR well without improvement after adding axillary response (c-index 0.82 versus 0.85, p = 0.63). In HER2-positive tumours, metabolic breast response predicted pCR poorly with improvement after adding axillary response (c-index 0.64 versus 0.72, p = 0.06).Conclusions 18F-FDG PET/CT response during NST differs between breast and axilla. In TN tumours, pCR total prediction can be made independent of metabolic axillary response. In HER2-positive tumours, axillary response may improve pCR total prediction. These findings may help guide PET/CT-response-based changes during NST.Trial registration NTR NTR1797. Registered 29 May 2009, retrospectively registered.Electronic supplementary materialThe online version of this article (doi:10.1186/s40644-017-0117-5) contains supplementary material, which is available to authorized users.

Is CT or FDG-PET more useful for evaluation of the treatment response in metastatic HER2-positive breast cancer? a case report and literature review

“…In some reports, the pathological complete response rate after neoadjuvant chemotherapy for HER2-positive BC has correlated with the treatment response evaluated by FDG-PET ( 10 – 13 , 15 – 21 ), whereas no correlation has been observed in other studies ( 22 – 26 ). Furthermore, for BC, the utility of FDG-PET may differ between primary sites and metastatic lymph nodes ( 27 ). Furthermore, the ability of PET to detect breast cancer is highly dependent on tumor size: the sensitivity for tumors less than 1 cm in diameter was 25%, whereas the sensitivity for tumors between 1 cm and 2 cm in diameter was 84.4% ( 28 ).…”

The Value of 18F-FDG PET/CT Imaging in the Evaluation of Interim Neoadjuvant Chemotherapy Response in Locally Advanced Breast Cancer

“…In our study, the mean ΔSUV max -T was higher in patients with pCR (+) groups than in patients with non-pCR. In another study, in which the metabolic and pathological response evaluation was performed separately for the breast and axilla with triple-negative and HER2 group patients, ΔSUV max -T was determined as the strongest estimator of pCR in the primary tumor and ΔSUV max -N was the most predictive of the total pCR ( 21 ).…”

Molecular imaging as biomarker for treatment response and outcome in breast cancer

“…IVc [19][20][21] High baseline uptake and no or low metabolic change (at 2-8 weeks treatment): related to shorter diseasefree survival and overall survival.…”