Abstract
BACKGROUND: The efficacy of prophylactic cranial irradiation (PCI) is still controversial in small cell lung cancer (SCLC) patients with pT1-2N0M0 disease after complete resection. The majority of previous studies haven't discerned the potential benefit of PCI in this subgroup of patients, probably due to the paucity of these patients and distinct treating modalities. The aim of this study is to demonstrate the potential medical benefit of PCI in these patients. METHODS: A retrospective study was conducted to evaluate the potential benefit of PCI in pT1-2N0M0 SCLC patients after complete resection. We retrospectively reviewed 112 pT1-2N0M0 SCLCs after complete resection and adjuvant chemotherapy between January 2013 and January 2022. Survival and Cox regression analysis were conducted to elucidate the potential medical benefit of PCI in these patients. RESULTS: The median overall survival (OS) has not been reached. The 2-year, 5-year, 8-year OS rate was 93.7%, 73.2%, and 65.7%, respectively. Brain metastasis (BM) was observed in 17.0% (19/112) patients during the process of follow-up. PCI significantly decreased the BM actuarial risk from 23.9 to 4.9% (log-rank p = 0.0097, HR = 0.180, 95% CI: 0.041-0.778). The brain metastasis free survival (BMFS, log-rank p = 0.02) and OS (log-rank p = 0.05) in PCI cohort were also significantly longer than that of non_PCI group. Cox analysis demonstrated that PCI was an independent prognostic factor in both BM actuarial risk (HR = 0.198, 95% CI: 0.046-0.859, p = 0.031) and BMFS (HR = 0.387, 95% CI: 0.169-0.890, p = 0.025). Moreover, T2 patients showed a significant superior prognosis in terms of BM actuarial risk with comparison to those with T1 disease in non_PCI cohort (log-rank p = 0.016, HR = 3.345, 95% CI: 1.177-9.511), whereas the difference could not be observed in PCI cohort. CONCLUSIONS: PCI was significantly associated with a better clinical outcome in pT1-2N0M0 SCLC patients who received complete resection and adjuvant chemotherapy, especially in T2 patients.