Does surgically resected small‐cell lung cancer without lymph node involvement benefit from prophylactic cranial irradiation?

Abstract

Background It has previously been demonstrated that surgically resected small‐cell lung cancer (SCLC) patients could benefit from prophylactic cranial irradiation (PCI). However, PCI in patients without lymph node involvement remains controversial. This study includes a larger sample size to evaluate the benefit of PCI therapy in this specific population. Methods The records of surgically resected SCLC patients without lymph node involvement (N0M0) in Shanghai Chest Hospital were retrospectively reviewed. Results Between January 2006 and May 2017, a total of 146 cases of surgically resected SCLC without lymph node involvement were included. A total of 46 patients received PCI therapy and 100 patients received no therapy. During the observation period, 12.0% (12/100) of the patients who did not receive PCI therapy developed brain metastases while 10.9% (5/46) of patients who received PCI therapy developed brain metastases. With regard to time to recurrence, no significant difference was observed among the groups (P = 0.798). Moreover, there was no significant difference in either the overall survival benefit (hazard ratio [HR] = 0.84, 95% confidence interval [CI]: 0.49–1.45, P = 0.532) or disease‐free survival rate (HR = 0.95, 95% CI: 0.52–1.75, P = 0.864). Conclusions The evidence obtained does not support PCI therapy in the management of surgically resected SCLC with no lymph node involvement. Key points Prophylactic cranial irradiation (PCI) remains controversial for resected small‐cell lung cancer (SCLC) without lymph node involvement. In this study, the results indicated that PCI does not reduce the risk of cerebral recurrence of resected p‐T1‐2N0M0 SCLC. This is the largest sample size study focused on PCI in resected p‐T1‐2N0M0 SCLC. Future revised versions of the guidelines should address this issue.

pN1 but not pN0/N2 predicts survival benefits of prophylactic cranial irradiation in small-cell lung cancer patients after surgery

“…Due to the paucity of cases undergoing surgery, the effect of PCI on SCLC patients who underwent surgical resection for the primary tumor remains unclear. We and other groups have shown that PCI could improve OS and decrease BM in SCLC patients with p-II/III stage, but not p-I stage, which is likely due to the low incidence of BM in patients with p-I stage (16)(17)(18)24). Specifically, recent data from our center showed that of the 146 surgically resected SCLC patients without lymph node involvement (pN0), only 11.6% (17/146) of patients developed BM, and PCI does not reduce the risk of cerebral recurrence of resected pT1-2N0M0 SCLC (17).…”

“…This survival benefit was evident from PSM-based univariate and multivariate Cox analyses. In general, pN0 belongs to the p-I stage that associates with a low incidence of BM (16)(17)(18)24), which could explain the unbeneficial role of PCI treatment in this subgroup. Additionally, we observed that PCI was not superior to the non-PCI group in patients with pN2, which predominantly belongs to p-stage III.…”

“…Accordingly, the National Comprehensive Cancer Network guideline has recommended surgery for LS-SCLC patients at an early-stage without lymph node metastasis (T1-2, N0). Besides, some recent studies have demonstrated that PCI can decrease the incidence of BM and improve the prognosis of patients with resectable LS-SCLC after surgery (14,(16)(17)(18); however, the target populations that can considerably benefit from PCI is not yet specified. Of note, PCI is known to be related to neurotoxicity, which needs to be critically considered before clinical employment.…”

The role of pulmonary resection in early stage small cell lung cancer

“…Of these, only manuscrpits dealing directly with surgical pulmonary resection in SCLC were selected. Based on these criteria, 14 publications were identified and included in the review [8][9][10][11][12][13][14][15][16][17][18][19][20][21](Tab. 1).…”

“…The role of pulmonary resection in early SCLC has been controversial for many decades [6]. Undoubtedly, it constitutes a valuable component of a combined modality treatment, especially in the situation when a small peripheral lesion detected at low-dose computed tomography (LDCT) is re-sected, and after the resection the diagnosis of SCLC is established [9,10]. However, many lung physicians do not refer patients with small peripheral pulmonary lesions for thoracic surgical resection when SCLC is suspected, but prefer observation.…”