Objective To observe the clinical efficacy of Aiyu Capsule in combination with FOLFOX4 chemotherapy for patients with median or advanced rectum cancer, and to investigate its impacts on cellular immune function and survival.

Methods A total of 347 patients with adenocarcinoma-type median or advanced rectum cancer were enrolled in this study from March 2018 to June 2019 were selected as study objects. Patients were divided into control group (173 patients) or observation group (174 patients) using an odd-even number system, and both groups were followed up for 36 months. The control group received FOLFOX4 chemotherapy, while the observation group additionally took Aiyu Capsule orally. Both groups underwent four consecutive treatment cycles.Clinical efficacy and traditional Chinese medicine (TCM) syndrome scores were evaluated after 2 and 4 cycles. Tumor markers, cellular immune function, adverse reaction rates, and cumulative survival rates were compared between the two groups before and after treatment.

Results After 2 and 4 cycles of treatment, the complete response rate and disease control rate were significantly higher in the observation group compared to the control group (P<0.05). After 2 cycles of treatment, disease control rate in the observation group was significantly higher than that in the control group (P<0.05). Both primary and secondary symptom scores, as well as total scores, decreased in both groups post-treatment, with lower scores in the observation group (P<0.05). Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) levels decreased in both groups after 2 cycles, with significant reduction in the observation group (P<0.05). After 4 courses of treatment, CEA and CA19-9 levels in two groups were lower than before treatment and 2 courses of treatment, and the observation group was lower than the control group (P<0.05). After two treatment cycles, the levels of CD3⁺, CD4⁺ T cells, and the CD4⁺ to CD8⁺ ratio(CD4⁺/CD8⁺) in the observation group were significantly elevated compared to pre-treatment, whereas the CD8⁺ T cell levels decreased significantly (P<0.05). After four treatment cycles, the control group demonstrated elevation in CD4⁺ T cell levels and the CD4⁺/CD8⁺ compared to the levels after two cycles (P<0.05). After four treatment cycles, the observation group had significant increase in CD3⁺, CD4⁺ T cell levels, and the CD4⁺/CD8⁺, whereas a significant reduction in CD8⁺ T cells compared to pretreatment (P<0.05). The incidence of dermatitis and liver function impairment was lower in the observation group (P<0.05). The Kaplan-Meier survival curve demonstrated a higher cumulative survival rate in the observation group (P=0.011).

Conclusion The combination of Aiyu Capsule and FOLFOX4 chemotherapy promotes immune function recovery, alleviates chemotherapy-related adverse reactions, extends survival outcomes, and enhances clinical efficacy in patients with median or advanced rectum cancer.