Abstract P6-02-15: TILs-US score using ultrasonography before chemotherapy predicts the outcome of neoadjuvant treatment in HER2 positive breast cancer
Authors: N Masumoto, T Kadoya, A Kanou, K Fukui, N Shiroma, S Sueoka, E Suzuki, G Noriko, S Sasada, A Emi, R Haruta, T Kataoka, K Arihiro, M Okada
Journal: Cancer Research (2019)

Abstract Purpose Tumor-infiltrating lymphocytes (TILs) have been reported to be predictive factors of therapeutic effect in neoadjuvant chemotherapy (NAC). And while TILs can be evaluated in preoperative biopsy tissue, heterogeneous distribution of TILs requires examination of all biopsied tissue samples. We gave scores to preoperative US images with characteristics indicative of LPBC and attempted to apply these for diagnostic prediction of LPBC. In this study, TILs-US score based on US images obtained before chemotherapy was examined as an alternative method to LPBC evaluated on preoperative biopsy tissues (pre-LPBC) for application in the prediction of pathological complete response (pCR). Methods We evaluated 67 patients in triple negative type (n=22), HER-2 positive (n=33), luminal type (n=12) with invasive breast cancer who underwent neoadjuvant chemotherapy between March 2012 and July 2016. Ultrasonography (US) was performed before NAC. All patients were treated by either mastectomy or breast-conserving surgery after NAC. Stromal lymphocytes were evaluated on preoperative biopsy tissues. Breast cancer samples with ≥ 50% stromal TILs were defined as LPBC. There were 39 cases of LPBCs and 122 cases of non-LPBCs in pathological specimens using a biopsy before NAC. TILs-US score (0˜7 point) was calculated from US before NAC. We set TILs-US score cut-offs for predicting LPBC at 4 points based on our previous data. Based on clinicopathological factors including TILs-US scores based on US and LPBC indicators before NAC, determinants useful for prediction of LPBC were examined. Results The surgical pathological findings after NAC indicated pCR and non-pCR in 32 (47.8 %) and 35 (52.2 %) patients. There were significant predictors for pCR in univariate (Clinical N: OR 2.83, p=0.043; HER-2: OR4.80, p=0.002; TILs-US score: OR 2.83, p=0.04) and multivariate analyses (HER-2: OR 6.42, p=0.009) in all breast cancer. There were not significant predictors for pCR in univariate and multivariate analyses in triple negative breast cancer. While, there were significant predictors for pCR in univariate (TILs-US score: OR17.5, p=0.002) and multivariate analyses (TILs-US score: OR 82.8, p=0.02) in HER2 positive breast cancer. Multivariate analysis for prediction of pCR in HER2 positive breast cancer Multivariate logistic analysisCharacteristicOR,95%CI,PAge, &amp;lt;50 v ≥5012.7,0.84-191.8,0.07Clinical T, T1-2 v T3- T416.5,0.23-1177.2,0.20Clinical N, Negative v Positive1.74,0.16-19.2,0.65Nuclear Grade, 3 v 1-22.57,0.12-55.7,0.55ER, Negative v Positive3.01,0.16-55.2,0.46LPBC, ≥50 % v &amp;lt;50 %3.52,0.22-55.2,0.37TILs-US score, ≥4 v &amp;lt;382.8,2.15-3186.8,0.02 Conclusions In patients with HER2 positive breast cancer, TILs-US score can predict the therapeutic effectin neoadjuvant chemotherapy (NAC) and help with the development of appropriate treatment plans. Citation Format: Masumoto N, Kadoya T, Kanou A, Fukui K, Shiroma N, Sueoka S, Suzuki E, Noriko G, Sasada S, Emi A, Haruta R, Kataoka T, Arihiro K, Okada M. TILs-US score using ultrasonography before chemotherapy predicts the outcome of neoadjuvant treatment in HER2 positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-15.