Prognostic impact of neutrophilia and lymphopenia on survival in anal cancer treated with definitive concurrent chemoradiotherapy: a retrospective multicenter study

Purpose: This study evaluated the prognostic value of leukocyte, lymphocyte, and neutrophil counts in anal cancer patients undergoing concurrent chemoradiotherapy (CCRT). Methods: Multi-institutional retrospective data review included 148 non-metastatic anal cancer patients treated with definitive CCRT with 5-fluorouracil plus mitomycin C between the year 2001 and 2019. The median radiation dose to the primary tumor was 54 Gy with a median pelvic dose of 45 Gy. Median follow-up duration was 56 months, and complete blood cell counts were analyzed from baseline to 1 year after the completion of radiotherapy. Results: Although most patients showed a normal number of blood cells before treatment, 6.1% and 4.1% of patients showed leukocytosis (> 10,000/μl) and neutrophilia (> 7500/μl), respectively. After the initiation of treatment, seven patients (4.7%) displayed grade 4 lymphopenia (< 200/μl) at 1 month. Patients with initial leukocytosis showed inferior progression- and locoregional progression-free survival, and neutrophilia was a prognostic factor in all survival outcomes. Grade 4 lymphopenia at 1 month was also significantly associated with overall, progression-, and distant metastasis-free survival. On multivariate analyses, baseline neutrophilia was associated with 56.8-, 22.6-, 10.7-, and 23.0-fold increased risks of death, disease relapse, locoregional progression, and distant metastasis, respectively. Furthermore, lymphocytes < 200/μl at 1 month was linked to 6.8-, 5.4-, and 6.3-fold increased risks for death, disease relapse, and distant metastasis, respectively. Conclusion: The number of leukocytes, lymphocytes, and neutrophils readily acquired from routine blood tests before and during treatment could be an independent prognostic factor of survival in patients with anal cancer.