Risk factors for brain metastases in completely resected small cell lung cancer: a retrospective study to identify patients most likely to benefit from prophylactic cranial irradiation

Abstract

BackgroundThe role of prophylactic cranial irradiation (PCI) on small cell lung cancer (SCLC) has been established based on the two-stage system of limited versus extensive disease and the treatment modality of chemoradiotherapy. However, the use of PCI after combined-modality treatment with surgery for resectable limited-stage SCLC has not been investigated sufficiently. We conducted a retrospective study to evaluate risk factors for brain metastasis (BM) in patients with surgically resected SCLC to identify those most likely to benefit from PCI.Patients and methodsThe records of 126 patients with completely resected SCLC and definitive TNM stage based on histological examination between 2003 and 2009 were reviewed. The cumulative incidence of BM was estimated using the Kaplan–Meier method and differences between the groups were analyzed using the log-rank test. Multivariate Cox regression analysis was applied to assess the risk factors of BM.ResultsTwenty-eight patients (22.2%) developed BM at some point during their clinical course. The actuarial risk of developing BM at 3 years was 9.7% in patients with p-stage I disease, 18.5% in patients with p-stage II disease, and 35.4% in patients with p-stage III disease (p = 0.013). The actuarial risk of developing BM at 3 years in patients with LVI was 39.9% compared to 17.5% in patients without LVI (p = 0.003). Multivariate analysis identified pathologic stage (hazard ratio [HR] = 2.013, p = 0.017) and LVI (HR = 1.924, p = 0.039) as independent factors related to increased risk of developing BM.ConclusionPatients with completely resected p-stage II-III SCLC and LVI are at the highest risk for BM.

Prophylactic cranial irradiation after definitive chemoradiotherapy for limited-stage small cell lung cancer: Do all patients benefit?

“…In one study, the frequency of BM to be 6.25% (2/32) among patients with TNM pathologic stage I disease, 28.2% (11/39) among those with stage II disease, and 29.1% (16/55) among those with stage III disease (19). Other trials have reported similar findings, with <10% of pathologic stage I tumors with subsequent BM compared with >20% of pathologic stage II or III tumors [20–23]. In those studies, tumor size could be measured directly after resection, in contrast to our study, which did not include patients with resected tumors; rather, tumors size was measured on diagnostic CT scans.…”

Patterns of failure in limited-stage small cell lung cancer: Implications of TNM stage for prophylactic cranial irradiation

“…[12–14] In one series from China, the investigators reported that the incidence of brain metastases was only 6% in patients with stage I SCLC, compared with 29% in patients with stage II–III SCLC. They concluded that patients with stage I SCLC may not require PCI after surgical resection.…”

Treatment outcomes of patients with small cell lung cancer without prophylactic cranial irradiation

“…Our results were better than previously reported outcomes of chemoradiotherapy and comparable to those of complete surgical resection. Zhu et al assessed the outcomes of patients with completely resected pathological stage II or III SCLC who did not receive PCI and reported 2-year survival rates of 78.6% among patients with stage II disease and 42.6% for those with stage III disease, with 5-year survival rates of 61.7% and 26.6%, respectively (18). Thus, these results should be considered reasonably favorable.…”