West Asia Organization for Cancer Prevention (WAOCP), APOCP's West Asia Chapter. Asian Pacific Journal of Cancer Prevention 1513-7368 25 11 2024 11 01 Poor Prognostic Effects of Lymphocytopenia Induced by Preoperative Chemoradiotherapy in Rectal Cancer 3799 3805 91385 10.31557/APJCP.2024.25.11.3799 EN Hyung Joo Baik Department of Surgery, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea. Min Sung An Department of Surgery, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea. Ji Sun Park Department of Nuclear Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea. Yunseon Choi Department of Radiation Oncology, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea. Journal Article 2023 09 03 Background: We evaluated the prognostic effect of lymphocytopenia caused by preoperative radiation therapy and chemotherapy in patients with rectal cancer. Methods: A total of 147 patients with rectal cancer who underwent preoperative chemoradiotherapy and surgical resection between 2008 to 2021 participated. Lymphocyte nadir less than 500/μl were defined as lymphocytopenia in this study. The relationship between lymphocyte nadir after chemoradiotherapy and disease-free survival (DFS) was evaluated. Results: Median follow-up was 60.7 months. A total of 21 patients (14.3%) showed lymphocytopenia related to preoperative chemoradiotherapy. Out of the original 147 patients, 29 (19.7%) patients had a diagnosis of diabetes mellitus, and 66 (44.9%) patients were overweight (body mass index exceeding 23). Lymphocytopenia occurred frequently in non-diabetic patients (p = 0.006) and non-overweight patients (p = 0.001). The pathologic complete response (pCR, n = 19) rate after chemoradiotherapy tended to be positively correlated with body mass index (p = 0.09). Lymphocytopenia was associated with lower DFS (p = 0.009). However, overall survival and intra-pelvic relapse-free survival were not associated with lymphocytopenia (p = 0.124 and p = 0.156). Conclusions: Lymphocytopenia induced by preoperative chemoradiotherapy is associated with lower DFS in patients with rectal cancer. Efforts to avoid lymphocytopenia may help prevent cancer recurrence. lymphocytopenia rectal cancer Chemotherapy Radiation therapy disease-free survival https://journal.waocp.org/article_91385_2c16d1c19375a4599d6ba62a4369a7fa.pdf