Prophylactic Cranial Irradiation for Extensive-Stage Small-Cell Lung Cancer: A Retrospective Analysis

Abstract

PurposeExtensive-stage small-cell lung cancer (esSCLC) is an incurable disease and represents a therapeutic challenge because of its poor prognosis. Studies in prophylactic cranial irradiation (PCI) in esSCLC have shown a decreased incidence of symptomatic brain metastases in patients who respond to systemic chemotherapy. However, its effect on overall survival is debatable. We evaluated the benefit of PCI in patients with esSCLC in terms of overall survival, progression-free survival, incidence of brain metastases, recurrence rate, and exposure to postrecurrence therapies.Materials and MethodsWe retrospectively reviewed electronic charts from patients diagnosed with esSCLC from 2008 to 2014 at our institution. All patients had negative baseline brain imaging before chemotherapy and PCI and received at least 4 cycles of platinum-based chemotherapy in the first-line setting without progressive disease on follow-up. PCI was performed at the discretion of the treating physician. Analyses were based on descriptive statistics. Survival curves were calculated by Kaplan-Meier method.ResultsAmong 46 eligible patients, 16 (35%) received PCI and 30 (65%) did not. Compared with no PCI, PCI led to improved progression-free survival (median, 10.32 v 7.66 months; hazard ratio, 0.4521; 95% CI, 0.2481 to 0.8237; P < .001) and overall survival (median, 20.94 v 11.05 months; hazard ratio, 0.2655; 95% CI, 0.1420 to 0.4964; P < .001) as well as lower incidence of brain metastases (19% v 53%; P = .0273) and higher exposure to second-line chemotherapy (87% v 57%; P = .0479).ConclusionCareful patient selection for PCI can improve not only brain metastases control and higher second-line chemotherapy exposure but also patient survival.

The effects of prophylactic cranial irradiation versus control on survival of patients with extensive-stage small-cell lung cancer: a meta-analysis of 14 trials

“…If the literature provided the univariate and multivariate analysis results of overall survival, the multivariate analysis results were used because they minimized the influence of confounding factors. Eight [ 7 – 10 , 18 , 20 , 24 , 25 ] of included studies provided HRs and related 95% CI. HRs were also obtained based on survival curves from five retrospective trials [ 17 , 21 – 23 , 26 ].…”

“…Five studies [ 7 , 10 , 18 , 20 , 25 ] reported progression-free survival (PFS) in patients receiving PCI versus control. The random effect model was used as the I 2 was 64%.…”

“…Five studies [ 7 , 10 , 18 , 20 , 25 ] reported the incidence of brain metastases after PCI. The estimated RR of PCI versus control was 0.47 (95% CI: 0.33, 0.69; P = 0.0001), indicating that PCI was associated with less risk of BM (Fig.…”

“…According to the sources of patients, the studies were classified as Eastern [ 10 , 17 , 20 – 23 , 26 ] and Western [ 7 – 9 , 18 , 19 , 24 , 25 ]. As indicated by I 2 , a significant heterogeneity was detected and the random effect model was used.…”

“…Ten studies used PCI to treat patients who responded to previous chemotherapy [ 7 – 10 , 17 , 20 , 22 – 25 ], and four studies used concurrent chemotherapy and PCI [ 18 , 19 , 21 , 26 ] to treat extensive-stage SCLC. As shown in Fig.…”