The following article features coverage from the IASLC 2019 World Conference on Lung Cancer meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Results of a meta-analysis of data from 4 clinical trials — SWOG 8300, RTOG 0214, NVALT-11, and Guangzhou 2005 — revealed a progression-free survival (PFS) benefit for patients with radically treated stage III non-small cell lung cancer (NSCLC) receiving prophylactic cranial irradiation (PCI) compared with observation. These findings were presented at the IASLC 2019 World Conference on Lung Cancer hosted by the International Association for the Study of Lung Cancer in Barcelona, Spain.

Although PCI has been shown to reduce the likelihood that brain metastases will develop in patients with localized NSCLC, an overall survival (OS) benefit of this treatment compared with observation alone has not been demonstrated, possibly because there were not many patients included in these clinical trials.

The aim of this current study was to evaluate the clinical outcomes of patients with stage III NSCLC treated with PCI by performing an Introduction to Individual Patient Data (IPD) meta-analysis using original data from a number of clinical trials.

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The primary end point of this study was OS, with PFS, brain metastasis-free survival, and toxicity as secondary end points.

Of the 924 patients included in the analysis, 68% were men, 94% had an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, and 37% had disease characterized by squamous histology. The median age was 61 years, and the median follow-up was 8.1 years.

Results of a separate analysis of the data from the SWOG 8300 trial (254 individuals) showed worse OS for patients treated with PCI compared with observation (hazard ratio [HR], 1.38; 95% CI, 1.07-1.79; P =.013). However, a combined analysis of data from the other 3 trials (670 individuals) did not reveal a significant difference in OS for patients receiving PCI versus observation (P =.228). Nevertheless, compared with observation, PFS (HR, 0.78; 95% CI, 0.65-0.92; P =.004), and brain metastasis-free survival (HR, 0.38; 95% CI, 0.27-0.53 P <.001) were significantly higher for those treated with PCI.

No safety data were available for the SWOG 8300 study, and only the NVALT-11 trial assessed toxicity in patients enrolled in the observation arm of the study.  Of the 456 patients available for the safety analysis, there was at least 1 grade 3 or higher adverse event in 19 patients treated with PCI. In the NVALT-11 trial, 11 of 86 patients treated with PCI and 4 of 88 patients undergoing observation only were reported to have experienced at least 1 grade 3 or higher adverse event.

In summarizing the results of this study, the authors stated that “although PFS and [brain metastasis]-free survival were improved for patients who received PCI, no significant PCI benefit for OS was observed.”

Read more of Cancer Therapy Advisor‘s coverage of the IASLC annual meeting by visiting the conference page.

Reference

De Ruysscher D, Lacas B, Le Pechoux C, et al. PCI for radically treated non-small cell lung cancer: A meta-analysis using updated individual patient data of randomized trials. Presented at: IASLC 2019 World Conference on Lung Cancer hosted by the International Association for the Study of Lung Cancer; September 7-10, 2019; Barcelona, Spain. Abstract OA12.01.