Adding local treatment to systemic therapy may extend survival among certain patients with oligometastatic non–small cell lung cancer (NSCLC), according to a retrospective look at more than 34,000 patients.
Surgical resection provided the greatest survival benefit, followed by external beam radiotherapy or thermal ablation (EBRT/TA), reported lead author Johannes Uhlig, MD, of University Medical Center Göttingen (Germany) and colleagues.
NSCLC patients with five or fewer metastatic sites (oligometastatic disease) are thought to achieve better outcomes than patients with more widely disseminated disease, the investigators noted in JAMA Network Open, but the benefit of local therapy for this population is unclear.
“A recent randomized, prospective study of 74 patients with oligometastatic NSCLC identified superior progression-free survival with local control after hypofractionated radiotherapy or surgical resection and radiotherapy compared with systemic therapy alone, suggesting an important application of local treatment options for patients with metastatic disease,” the investigators wrote.
To build on these findings, the investigators retrospectively evaluated 34,887 patients with stage IV NSCLC who had up to one distant metastatic lesion in the liver, lung, brain, or bone, as documented in the National Cancer Database. Treatment groups were divided into patients who received systemic therapy alone, surgical resection plus systemic therapy, or EBRT/TA plus systemic therapy. Multivariable Cox proportional hazards models were used to compare overall survival among the three groups.
Including a median follow-up of 39.4 months, data analysis showed that patients who underwent surgery and systemic therapy fared the best. Adding surgery reduced mortality risk by 38% and 41%, compared with EBRT/TA plus systemic therapy and systemic therapy alone, respectively (P less than .001 for both). Compared with systemic therapy alone, adding EBRT/TA reduced mortality risk by 5% (P = .002).
The impact of EBRT/TA varied among subgroups. For those with squamous cell carcinoma who had limited nodal disease, adding EBRT/TA resulted in a clear benefit, reducing mortality risk by 32% (P less than .001). Compared with systemic therapy alone, this benefit translated to higher survival rates for up to 3 years. Conversely, adding EBRT/TA increased risk of death by 39% among patients with extended local and distant adenocarcinoma (P less than .001). In this subgroup, survival rates over the next 3 years were higher among patients treated with systemic therapy alone.
“The present study supports a combined approach of local therapy in addition to systemic treatment for select patients with oligometastatic NSCLC,” the investigators concluded.
The study was funded by the U.S. Department of Defense. The investigators disclosed additional relationships with Bayer, AstraZeneca, Bristol-Myers Squibb, and others.
SOURCE: Uhlig et al. JAMA Netw Open. 2019 Aug 21. doi: 10.1001/jamanetworkopen.2019.9702.