The role of haematological parameters in predicting the response to radical chemoradiotherapy in patients with anal squamous cell cancer

Background. Historically, the treatment of choice for anal cancer had been abdominoperineal resection (APR). Radical radiotherapy with concurrent 5-fluorouracil plus mitomycin C chemotherapy was later established as standard therapy, although with a failure rate of 20–30%. The aim of this study was to evaluate the outcomes after radical chemoradiotherapy (CRT), prognostic and predictive factors and patterns of failure. Patients and methods. This study included 47 patients treated with radical CRT for patohistologicaly confirmed anal squamous cell carcinoma. Analysed haematological parameters included: neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and haemoglobin level. The final logistic regression model included treatment break period. Tumour response was assessed at 24 weeks from CRT completion. Follow-up was performed every 3 months during the first two years, and every 6 months thereafter. Results. A complete clinical response (CR) was detected in 30 patients (63.8%). Patients who did not achieve a 6-months CR and those who had a CR after 6 months but then relapsed were referred to surgical treatment. With combined CRT and surgical salvage treatment the CR rate was 80.9%. Patients with CR after 6 months had significantly longer disease-free survival (DFS), progression-free survival (PFS), and overall survival (OS). A significant effect on the 6-month response was confirmed for PLR (p = 0.03). Conclusions. Important prognostic factors associated with CR were baseline haemoglobin level and period of treatment interruptions. Potential haematological prognostic factors could be PLR and NLR, which can be routinely determined by low-cost and minimally invasive methods.This study is supported by the Ministry of Education and Science of the Republic of Serbia (Agreement No. 451-03-9/2021-14/200043). This article is based upon work from COST Action CA17118, supported by COST (European Cooperation in Science and Technology); www.cost.eu. MC is supported by the Science Fund of the Republic of Serbia (PROMIS TRACEPIGEN project No. 6060876)