Abstract P6-02-06: Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction

Abstract

Abstract [Purpose] Tumor-infiltrating lymphocytes (TILs) is a prognostic factor for breast cancer, however, an accurate and simple evaluation method remains elusive. Therefore, we focused on findings characteristic of lymphocyte-predominant breast cancer (LPBC) in ultrasound (US) images. In this study, the application of preoperative US image assessment to diagnostic prediction of LPBC evaluated from postoperative pathological specimens, was appraised. [Methods] We evaluated 191 patients with invasive breast cancer between January 2014 and December 2017. All patients were treated by either mastectomy or breast-conserving surgery. Stromal lymphocytes were evaluated on surgical pathological specimens. Breast cancer samples with ≥ 50% stromal TILs were defined as LPBC. Preoperative US was performed in all cases and images were examined for characteristics indicative of TILs. Scores were given to US images with characteristic TILs and these TILs-US scores were assessed for their application to predict LPBC. [Results] There were 39 cases of LPBCs and 122 cases of non-LPBCs in surgical pathological specimens. The characteristic US image findings predicting LPBC were shape (more lobulated), internal echo level (weaker) and posterior echoes (stronger). The TILs-US scores were given based on these three ultrasound tissue characterizations.We set TILs-US score cut-offs for predicting LPBC at 4 points (Sensitivity, 0.73; specificity, 0.87; accuracy, 0.83) based on the receiver operating characteristics (ROC) curves (AUC, 0.88). There were significant predictors for LPBC in maltivariate logistic analysis (Nuclear Grade (NG): OR3.4, p=0.02; ER: 5.7, p =0.007;HER-2: OR4.1, p=0.04; TILs-US score2: OR14.9, p<0.001) in preoperative clinicopathological factor. The sensitivity, specificity and accuracy of NG for predicting LPBC were 0.75, 0.69 and 0.71. Those of ER and HER2 were 0.33, 0.96 and 0.79.Sensitivity, specificity, and accuracy of NG, ER, and HER2 diagnoses were all lower than the TILs-US score, and the TILs-US score showed the best diagnostic ability. The sensitivity, specificity and accuracy of predicting LPBCPerformance measureTILs-US score (95%CI)NGER or HER-2P, TILs-US score vs. NG,P, TILs-USscore vs. ER or HER-2Sensitivity0.73 (0.63-0.81)0.75 (0.64-0.84)0.327 (0.24-0.39)0.08<0.001specificity0.87 (0.83-0.90)0.69 (0.65-0.72)0.957 (0.93-0.98)<0.001<0.001accuracy0.83 (0.77-0.88)0.707 (0.65-0.376)0.785 (0.74-0.82)0.0040.25 Conclusions LPBC has characteristic ultrasound tissue characterizations in US images. Thus, TILs-US scores based on US may be applicable to accurate and convenient preoperative diagnosis of LPBC. Citation Format: Fukui K, Masumoto N, Shiroma N, Kanou A, Yokozaki M, Sasada S, Emi A, Kadoya T, Arihiro K, Okada M. Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction [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 P6-02-06.