Effect of immune-modulating metronomic capecitabine as an adjuvant therapy in locoregionally advanced nasopharyngeal carcinoma

Abstract

Introduction Metronomic capecitabine used as an adjuvant therapy improves survival in patients with locoregionally advanced nasopharyngeal carcinoma (LA-NPC). This therapeutic approach may also contribute to improving immune function, consequently enhancing overall therapeutic efficacy. Aim We aimed to evaluate the effect of metronomic capecitabine as adjuvant therapy on immune function and survival in cases of LA-NPC. Subjects and methods 28 patients with LA-NPC were enrolled in the study and equally assigned to two groups of 14 each: experimental and control group. The experimental group received induction chemotherapy + concurrent chemotherapy + adjuvant chemotherapy as well as oral capecitabine at a dose of 650 mg/m² of body surface area twice daily for 1 year, with the option to discontinue in case of intolerance. The control group did not receive additional chemotherapy or targeted drugs after the induction chemotherapy + concurrent chemoradiotherapy; however, they were followed up regularly. Changes in immune function and survival were compared between the two groups. Results The median follow-up time was 43.5 months. One year after adjuvant chemotherapy, the experimental group showed higher levels of CD8 + cells, CD28 + CD8 + cells, and activated CD8 + cells compared to the control group (P < 0.05). The CD4/CD8 ratio and proportion of monocyte-derived dendritic cells were also higher in the experimental group than in the control group, but the difference was not statistically significant (P ≥ 0.05). Comparisons of 3-year overall survival, local-regional recurrence-free survival, progression-free survival, and distant metastasis-free survival between the two groups showed percentages of 92.9% vs. 78.6%, 92.9% vs. 92.9%, 78.6% vs. 71.4%, and 85.7% vs. 0.78 0.6% respectively, but these differences were not significant (P > 0 0.05 ). Conclusion Metronomic capecitabine chemotherapy was observed to induce an immunomodulatory effect in LA-NPC. Trial registration NCT02958111, date of registration 04-11-2016.