TOPLINE:

In a systematic review and meta-analysis, consolidative thoracic radiotherapy (cTRT) was associated with improved overall survival and progression-free survival in patients with extensive-stage small cell lung cancer (SCLC), including those with brain metastases.

METHODOLOGY:

• The addition of cTRT to platinum-etoposide chemotherapy can improve survival among patients with extensive-stage SCLC. However, immune checkpoint inhibition in combination with chemotherapy has become standard first-line treatment. The role of cTRT in the era of chemoimmunotherapy remains unclear.
• To investigate, researchers conducted a systematic review and meta-analysis of 20 studies (18 retrospective cohort studies and two prospective trials) including 5282 patients with extensive-stage SCLC.
• Overall, 2436 patients received cTRT combined with chemoimmunotherapy, and 2846 patients received chemoimmunotherapy alone.
• Outcomes included overall survival, progression-free survival, grade 3 or higher treatment-related adverse events, and the pooled prevalence of radiation-induced pneumonitis and esophagitis. Outcomes among patients with brain or liver metastases at baseline were analyzed separately.

TAKEAWAY:

• cTRT combined with chemoimmunotherapy was associated with improved overall survival (hazard ratio [HR], 0.57; P < .001). Median overall survival was 20.25 vs 14.55 months among patients who received cTRT vs chemoimmunotherapy alone.
• Similarly, cTRT was associated with improved progression-free survival (HR, 0.53; P < .001). Median progression-free survival increased from 6.47 months without cTRT to 9.85 months when it was added to chemoimmunotherapy.
• Among patients with baseline brain metastases, cTRT was linked to improved overall survival (HR, 0.57; P = .01) and progression-free survival (HR, 0.42; P < .001). Radiotherapy also appeared to increase brain metastasis-free survival (HR, 0.46; P < .001), suggesting a possible abscopal effect, the authors of the study noted. However, in patients with baseline liver metastasis, cTRT showed no survival benefit.
• Overall, the addition of cTRT was not associated with an increased risk for severe treatment-related adverse events (odds ratio [OR], 1.55; P = .25). However, cTRT did raise the risk for pneumonitis, both grade 3 or higher (OR, 11.48; P = .02) and any grade (OR, 17.38; P < .001). Grade 3 or higher pneumonitis and esophagitis were observed in 3.86% and 1.27% of patients receiving cTRT, respectively. All cases of treatment-related esophagitis occurred in the cTRT group.

IN PRACTICE:

“Since most evidence comes from retrospective studies, our findings should be interpreted as a summary of current data rather than clinical guidance,” the study authors wrote. Ongoing clinical trials, including RAPTOR and TREASURE, they added, are expected to clarify the role of cTRT in chemoimmunotherapy regimens for patients with extensive-stage SCLC.

SOURCE:

The study, led by Dominik Wróbel, Jagiellonian University Medical College, Krakow, Poland, was published online in Radiotherapy and Oncology.

LIMITATIONS:

Radiotherapy was predominantly administered to patients who responded to initial chemoimmunotherapy, whereas those with early progression were typically excluded, potentially biasing outcomes in favor of cTRT. Institutional discretion and multidisciplinary decision-making introduced selection bias. Baseline characteristics varied between patients receiving cTRT and those not receiving it.

DISCLOSURES:

The study did not receive any funding. The authors declared having no relevant conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.