Significant improvement in overall survival with postoperative traditional Chinese medicine in stage I lung adenocarcinoma: a real-world retrospective cohort study.

Background: The clinical efficacy of traditional Chinese medicine (TCM) in the postoperative management of early-stage lung adenocarcinoma (LUAD) remains unclear, particularly in patients who do not receive adjuvant therapy. This real-world retrospective cohort study evaluated the association between postoperative TCM and long-term prognosis in patients with pathological stage I LUAD. Methods: We retrospectively analyzed pathological stage I LUAD who underwent radical R0 resection and did not receive postoperative adjuvant chemotherapy, radiotherapy, targeted therapy, or immunotherapy. Patients were classified into the TCM group (n=405) and the follow-up group (n=371) according to documented postoperative use of individualized TCM decoctions. Postoperative TCM exposure was defined as continuous individualized herbal decoction treatment for at least 6 months after surgery, prescribed according to syndrome differentiation. Baseline variables included gender, age, smoking status, family history, and T stage. Follow-up was performed through outpatient visits, imaging review, medical record review, and telephone contact until February 16, 2026. The primary endpoint was overall survival (OS), and the secondary endpoint was recurrence-free survival (RFS). The primary analysis used unweighted multivariable Cox regression, and stabilized inverse probability of treatment weighting (sIPTW) analysis was performed as a sensitivity analysis. Results: A total of 776 patients were analyzed. Over the median follow-up of 92.5 months, 50 death events and 145 recurrence events were documented. After sIPTW adjustment, baseline covariates were well balanced (absolute standardized mean differences <0.01). TCM was associated with improved OS [adjusted hazard ratio (aHR): 0.387, 95% confidence interval (CI): 0.214-0.698; P=0.002], corresponding to a 61.3% reduction in mortality risk. In the TCM group, RFS showed a favorable but non-significant trend (aHR: 0.811, 95% CI: 0.582-1.130; P=0.22). Subgroup analyses demonstrated that the protective effect of TCM on OS was generally consistent across most clinical subgroups, particularly in females (aHR =0.215, 95% CI: 0.061-0.750) and patients aged ≥60 years (aHR =0.413, 95% CI: 0.206-0.828). Conclusions: Postoperative TCM is associated with significantly improved OS in stage I LUAD patients without adjuvant therapy, suggesting its potential role as a complementary maintenance approach requiring prospective validation.