2632 - Ring-like uptake appearance on dedicated breast positron emission tomography before chemotherapy predicts outcome of neoadjuvant chemotherapy in breast cancer

Background

Dedicated breast positron emission tomography (DbPET) with ¹⁸F-fluorodeoxyglucose (FDG) can detect intratumoral heterogeneity. In a previous study, we proved that intratumoral heterogeneous distribution of FDG on DbPET is significantly related to a high nuclear grade and high Ki-67 proliferation index; we also proved that DbPET is useful for predicting residual breast tumors after neoadjuvant chemotherapy (NAC). This study included patients with breast cancer who exhibited a ring-like uptake without central FDG accumulation on DbPET and aimed to evaluate whether the uptake can predict the effects of NAC in patients with breast cancer.

Methods

The study included 83 consecutive patients with breast cancer who subsequently underwent DbPET and NAC between August 2016 and March 2019 and evaluated the relationship between pathological response to NAC and clinicopathologic factors (clinical T1: n = 14; clinical N0: n = 33; nuclear grade 1 or 2: n = 22; Ki67 ≥ 20: n = 78; ER positive: n = 52; and HER-2 positive: n = 32), such as intratumoral heterogeneous distribution of FDG (positive: n = 54) and ring-like uptake without central FDG accumulation (positive: n = 11) on DbPET images.

Results

Surgical pathological findings obtained after the NAC indicated pathological complete response (pCR) and non-pCR in 32 (38.6%) and 51 (61.4%) patients, respectively. For all the patients, significant predictors for pCR were identified in univariate analyses (clinical T: odds ratio = 3.60, p = 0.03; clinical N: odds ratio = 2.48, p = 0.049; HER-2 overexpression: odds ratio = 2.72, p = 0.03; and ring-like uptake: odds ratio = 5.33, p = 0.01) and multivariate analyses (HER-2 overexpression: odds ratio = 3.29, p = 0.03; ring-like uptake: odds ratio = 17.6, p = 0.0006) (Table).Table:

279P Univariate and multivariate logistic analysis of significant predictive clinicopathological factors for pCR

Conclusions

Ring-like uptake on DbPET provides predictive value for evaluating pCR to NAC in patients with breast cancer and might inform therapeutic decisions.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.