Background/Purpose: For esophageal cancer patients, combination chemotherapy with docetaxel, cisplatin, and 5FU (DCF therapy) is adopted for neoadjuvant chemotherapy (NAC). Although the response rate is high (72.5%), further investigation of indicators to predict its therapeutic effects is needed because of its side effects, and few have been reported. In this study, we obtained peripheral blood before and after the DCF therapy, analyzed various immune related cells by flow cytometry and tried to identify indicators to predict its therapeutic effects.

Subjects/Methods: Peripheral blood were obtained from 20 esophageal cancer patients before and after preoperative DCF therapy. During two cycles of one-week-on and three-week-off administration, peripheral blood was collected before and after each “on” and before and after the surgical treatment followed by. By flow cytometry, CD15+CD14 granulocytes and CD15CD14+ monocytes were observed. The effectiveness of NAC was determined hisitopathologically in accordance with the grading system of the Japanese Classification of Esophageal Carcinoma. Grading was as follows: Grade 0, no part of the tumor was affected; Grade1, less than two-thirds of the tumor was affected; Grade2, between two-thirds and the entire tumor was affected; and Grade 3, no residual tumor was present (Pathologically complete response) and clinically RECIST. Then their association were analyzed.

Results/Discussion: Of 20 patients with esophageal cancer, 13 patients were responders and 7 patients were non-responders to the DCF therapy. Just after the first “on” course, the ratio of monocytes to myelocytes was observed in 25.4 ± 32.0% in the non-responders and 7.8 ± 10.3% in the responders (p = 0.073). The numbers of monocytes calculated were 229.4 ± 212.2 /μL in the non-responders and 51.1 ± 71.1 /μL in the responders (p = 0.01). Patients with better pathological or clinical responses showed lower ratio of monocytes to myelocytes and fewer number of monocytes in peripheral blood. No relationship was observed between granulocytes and the therapeutic response.

Conclusion: These results suggest that analyzing immune related cells in peripheral blood might be useful for identification of predictive indicators for the response of preoperative DCF therapy.

Citation Format: Tomohira Takeoka, Kumiko Goto, Mitsunobu Matsumoto, Yasuhiro Miyazaki, Tomoki Makino, Tsuyoshi Takahashi, Yukinori Kurokawa, Makoto Yamasaki, Shuji Takiguchi, Masaki Mori, Yuichiro Doki, Hisashi Wada. Chemotherapy for esophageal cancer: Off-target effect and biomarker [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B135.