Progression-free survival (PFS) was nearly tripled with stereotactic body radiation therapy (SBRT) prior to maintenance chemotherapy in patients with limited metastatic non-small cell lung cancer (NSCLC) compared with chemotherapy alone, according to data presented at the 59th Annual Meeting of the American Society of Radiation Oncology (ASTRO). 

Although maintenance chemotherapy significantly improves PFS and overall survival (OS) in patients with NSCLC, results are often not durable.

For this phase 2 study, investigators randomly assigned 29 patients with metastatic stage IV NSCLC with partial response or stable disease after induction chemotherapy to receive either SBRT followed by maintenance chemotherapy or maintenance chemotherapy alone. Median follow-up was 9.6 months.

Patient accrual was stopped early after an unplanned interim analysis revealed significantly improved survival rates in the SBRT arm. Results showed that the median PFS was 9.7 months in the patients receiving SBRT prior to chemotherapy compared with 3.5 months in patients receiving maintenance chemotherapy alone (P =.013).

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Patients receiving SBRT plus chemotherapy were observed to have no instances of recurrence at original disease sites compared with 7 instances of recurrence in patients receiving chemotherapy alone. At the time of analysis, 67% of patients receiving only chemotherapy had progressed compared to 28% of patients receiving SBRT. None of the recurrences in patients receiving SBRT occurred in radiation treated areas.

Both treatment arms also reported having comparable toxicity profiles.

The results of the study showed that patients with advanced NSCLC achieve significantly prolonged PFS if treated with SBRT prior to chemotherapy compared with chemotherapy alone. The authors also noted that “a phase 3 study, based on this and other trials, has been activated by NRG to answer the benefit of local therapy on OS.”

Reference

1. Adding radiation to chemotherapy may dramatically improve survival for advanced-stage NSCLC patients [news release]. San Diego, CA: American Society for Radiation Oncology; September 24, 2017. https://prnmedia.prnewswire.com/news-releases/adding-radiation-to-chemotherapy-may-dramatically-improve-survival-for-advanced-stage-nsclc-patients-300524715.html?tc=PRNJ_email_html_abstract. Accessed September 26, 2017.