Effects of traditional Chinese medicine combined with chemotherapy for extensive-stage small-cell lung cancer patients on improving oncologic survival: study protocol of a multicenter, randomized, single-blind, placebo-controlled trial

Background Extensive-stage small-cell lung cancer (ES-SCLC) is characterized by extensive metastases, aggressive progression, and poor prognosis. Chemotherapy is applied as a preferred first-line regimen for ES-SCLC, but inadequate for improving its overall survival. Traditional Chinese medicine (TCM) is widely used in the clinical practice of ES-SCLC for its synergy with chemotherapy. However, there is still no substantial evidence to prove that TCM can effectively improve the long-term efficacy of ES-SCLC patients. The study intends to determine whether the TCM with chemotherapy can improve the overall survival (OS) in treating with ES-SCLC when compared with chemotherapy alone. Method/design A multicenter, randomized, single-blind, placebo-controlled clinical trial will be conducted to determine whether the TCM granules combined with chemotherapy can improve the OS of ES-SCLC. Two hundred seventy participants will randomly receive 4-6 cycles (21 days per cycle) of chemotherapy plus TCM granules or placebo. The primary outcome measure is OS. The secondary outcome measures includes progression-free survival (PFS), objective response rate (ORR), quality of life (QoL), and tumor markers. Visits will be performed at the end of each cycle during the treatment period and then every 3 months in the follow-up period until the patients' death or study completion. Discussion The study's result will provide a high-level evidence for TCM granules using with chemotherapy on the first-line treatment of ES-SCLC. Trial registration Chinese Clinical Trial Registry ChiCTR1900022991. Registered on 6 May 2019 (prospective registration). Keywords: Extensive-stage small-cell lung cancer (ES-SCLC), Traditional Chinese medicine (TCM), Randomized controlled trial (RCT), Overall survival (OS), Quality of life (QoL)