A prospective clinical study on the effectiveness of Phellinus igniarius decoction in treating immune dysfunction in colorectal cancer patients following chemfotherapy.

BACKGROUND AND AIM: Chemotherapy for colorectal cancer (CRC) frequently induces immune dysfunction, which can negatively affect patient prognosis. Phellinus igniarius, a traditional Chinese medicinal fungus, exhibits immunomodulatory potential, yet clinical evidence supporting its use in postchemotherapy immune recovery remains scarce. This study aimed to evaluate the efficacy and safety of Phellinus igniarius Decoction (PEG) in treating postchemotherapy immune dysfunction in patients with CRC and identify potential beneficiaries. EXPERIMENTAL PROCEDURE: This prospective, randomized, controlled trial enrolled patients with CRC who completed chemotherapy between January 2021 and June 2024. Participants were randomized (1:4:1) to receive placebo (N = 33), PEG (N = 132), or thymalfasin (N = 33). Thymalfasin (1.6 mg subcutaneously twice weekly), PEG (15 g/day orally), or placebo was administered for 8 weeks. Primary outcomes included changes in peripheral blood immune cell subsets (CD4+/CD8+ ratio and percentage of NK cells) and cytokines (Th1/Th2 balance). Secondary outcomes included quality of life (QOL) scores (EORTC QLQ-C30) and adverse events. Finally, the dominant Traditional Chinese Medicine (TCM) syndrome type in the PEG group was identified. RESULTS AND CONCLUSION: The PEG group demonstrated significant increases in the proportions of CD4+ T cells (p < 0.001), the percentage of NK cells (p < 0.05), and the levels of Th1 cytokines (IL-2 and IFN-γ), and a reduction in the levels of Th2/inflammatory factors (IL-4, IL-10 and TNF-α) (p < 0.05). It also improved quality of life scores (p < 0.05), with adverse event rates comparable to those of the controls. Subgroup analysis revealed that patients with spleen-kidney deficiency syndrome composed the optimal responder subgroup. PEG effectively restored immune function, improved quality of life, and was favorable for in postchemotherapy patients with CRC, with those exhibiting spleen-kidney deficiency syndrome representing the primary beneficiary population.