Abstract P5-02-01: Predictive value of TILs in evaluation of 18F-FDG-PET in breast cancer
Authors: T Hirakata, F Takaaki, S Kurozumi, C Katayama, R Yajima, S Obayashi, Y Nakazawa, N Tokuda, K Yanai, C Honda, H Kuwano
Journal: Cancer Research (2018)

Abstract Background: Several recent clinical studies have evaluated the prognostic and predictive importance of tumor-infiltrating lymphocytes (TILs) in breast cancer (BC). 18F-Fluorodeoxyglucose positron-emission (FDG-PET) CT was found to be effective for monitoring cancer cell viability of tissues and tumors, and it is used to evaluate the glucose metabolic rates of such tissues because most neoplasms have high glycolytic rates. FDG-uptake is also influenced by many factors, including inflammatory cells. In the present study, we investigated the relationship in evaluation of FDG-PET and degrees of TILs. Patients and Methods: Invasive carcinoma tissues of 100 breast cancer patients were examined. All patients underwent surgery. None of the patients had received preoperative chemotherapy. The proportional grades of stromal (Str)-TILs in surgical specimens were determined as follows: low (0-10%), intermediate (20-40%) and high (50-90%) grade, using the criteria of the International Working Group for TILs 2014 in breast cancer, using an immunohistochemical (IHC) method. The evaluation of PET was determined as follows, using standardized uptake value max (SUV max): low (&amp;lt;5) and high (&amp;gt;5). Estrogen receptor (ER), progesterone receptor (PgR), HER2, Ki67, and nuclear glade were also measured by IHC. Results: Among the 100 patients, range of age was 36 to 86 (mean 58) years. Twenty-seven patients were pre-menopausal, seventy-one were postmenopausal, and two were unknown. Invasive ductal carcinoma was diagnosed in 97 (97%) of the patients, invasive lobular carcinoma was diagnosed in 2 (2%), and others was 1 (1%).We divided the cases into three groups based on the degrees of TILs, low (57%), Intermediate (33%) and high (10%). We divided the cases into three based on the degrees SUV max, low (78%) and high (22%). High TILs group significantly showed higher SUV max than that of lower SUV max group (P=0.009). High TILs group had statistically higher rates of ER negative (P=0.001), PgR negative (P=0.002), HER2 positive (P=0.007), and nuclear grade 3 (P=0.013) than those of low TILs group. Conclusion: The proportional grades of stromal (Str)-TILs were associated with the degrees of SUV max in primary breast tumor in FDG-PET. High FDG uptake is predictive of poor prognosis and aggressive features in patients with breast cancer. From our findings, the evaluation of TILs is to be useful for predicting a better prognosis or therapeutic effect in cases with high FDG-uptake which indicate higher risk of recurrent disease. Citation Format: Hirakata T, Takaaki F, Kurozumi S, Katayama C, Yajima R, Obayashi S, Nakazawa Y, Tokuda N, Yanai K, Honda C, Kuwano H. Predictive value of TILs in evaluation of 18F-FDG-PET in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-02-01.