Adjuvant treatment with Cordyceps sinensis for lung cancer: A systematic review and meta-analysis of randomized controlled trials

Ethnopharmacological relevance: Cordyceps sinensis (CS) is a fungus parasitic on lepidopteran larvae which is often used to treat lung diseases and regulate immune function. Aim of the study: This review aimed to evaluate the efficacy of CS in the adjuvant treatment of lung cancer. Materials and methods: As of June 2022, the electronic database search was conducted in PubMed, EMBASE, Cochrane Library, China Biomedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), Wanfang Database and China Science Journal Database (VIP database). Randomized clinical trials (RCTs) that evaluated the efficacy of CS as an adjuvant treatment for lung cancer were included. After the quality evaluation, meta -analysis was performed with Stata 16.0 software. Results: A total of 12 RCTs with 928 patients were identified for this meta -analysis, which showed that as an adjuvant treatment, CS has the following advantages in the treatment of lung cancer: (1) Improved tumor response rate (TRR) (RR: 1.17 , 95%CI: 1.05-1.29 , P = 0.00); (2) improved immune function, including increased CD4 (MD: 4.98, 95%CI: 1.49-8.47, P = 0.01), CD8 (MD: 1.60, 95%CI: 0.40-2.81, P = 0.01, I 2 = 0.00%), NK (MD: 4.17, 95%CI: 2.26-6.08, P = 0.00), IgA (MD: 1.29, 95%CI: 0.35-2.24, P = 0.01), IgG (MD: 3.95, 95%CI: 0.98-6.92, P = 0.01) and IgM (MD: 6.44, 95%CI: 0.63-12.26, P = 0.03); (3) improved patients' quality of life based on the mean +/- SD of Karnofsky Performance Status (KPS) (MD: 8.20, 95%CI: 6.87-9.53, P = 0.00); (4) reduced the incidence of adverse drug reactions (ADRs), including the incidence of myelosuppression (RR: 0.38, 95%CI: 0.19-0.75, P = 0.01), leukopenia (RR: 0.76, 95%CI: 0.63-0.92, P = 0.00), and thrombocytopenia (RR: 0.52, 95%CI: 0.31-0.86, P = 0.01) (5) reduced the incidence of radiation pneumonitis (RR: 0.74, 95%CI: 0.62-0.88, P = 0.00). However, the number of improved patients based on KPS (RR: 1.47, 95%CI: 0.98-2.20, P = 0.06) were similar between two groups, liver and renal damage (RR: 0.32, 95%CI: 0.09-1.10, P = 0.07) and gastrointestinal adverse reactions (RR: 0.80, 95%CI: 0.47-1.37, P = 0.42) as well. Subgroup analysis showed that CS could increase the TRR in the treatment with 6 g/d and 21 days/3-4 cycles. Conclusion: Compared with conventional treatment, adjuvant treatment with CS of lung cancer not only improve TRR, QOL and immune function, but also reduce the incidence of ADRs and radiation pneumonitis. The optimal usage may be 6 g/d and 21 days/3 to 4 cycles. PROSPERO registration No: CRD42022333681.