SAN DIEGO — Aggressive consolidative therapy to the primary tumor and metastatic sites was associated with improved survival in stage IV non-small cell lung cancer (NSCLC) patients with three or fewer metastases, a retrospective single-center study found.
At a median 52 months follow-up, overall survival (OS) in the 121 patients who received comprehensive local consolidation therapy (LCT) was 29 months compared with 23 months in the 73 patients who received sub-comprehensive or no LCT (P=0.026), findings that held up on multivariate analysis to account for disease and patient characteristics, reported Erin Corsini, MD, of MD Anderson Cancer Center in Houston.
OS favored the comprehensive LCT group — which included treatment with surgery, radiotherapy, or both — at all time points:
- 1-year: 85% versus 72%
- 3-year: 43% versus 35%
- 5-year: 32% versus 19%
“Comprehensive local consolidation was associated with durable long-term survival, with 1- and 5-year survival rates approximating that historically [were] observed in earlier stages of disease,” Corsini said in a press briefing ahead of the Multidisciplinary Thoracic Cancers Symposium here.
For patients treated with LCT, squamous histology, higher intrathoracic disease burden, and bone metastases were associated with worse survival. New metastases in this group were more frequent (about 50%) than progression at the treated primary or oligometastatic sites (about 20% each).
“Given our findings, we speculated that patients with adenocarcinoma, low intrathoracic disease burden, and absence of bone metastases constitute those patients most likely to derive a durable survival benefit from aggressive consolidation,” Corsini said. “The observed rates of systemic failure in this cohort highlight the need to further examine whether the benefits associated with this novel treatment paradigm can be further enhanced by the use of contemporary systemic agents.”
Press briefing moderator Charles B. Simone II, MD, of New York Proton Center in New York City, said the survival benefit seen among the group receiving LCT was “quite impressive.”
“Overall, this study supports the findings from several recent randomized trials on radiation therapy for oligometastatic disease,” said Simone. “It gives us further justification to deliver early local therapy in patients with three or fewer sites of metastatic disease in an attempt to improve local control, progression-free survival [PFS], and even overall survival.”
He noted that at the 2018 American Society for Radiation Oncology (ASTRO) meeting, the SABR-COMET trial reported a 6-month median PFS improvement in patients with various oligometastatic cancers treated with stereotactic ablative radiotherapy, and another phase II study at the meeting in oligometastatic NSCLC reported a 24.2-month OS advantage for patients treated with either radiotherapy or surgery to the primary and metastatic sites.
The current study included 194 stage IV NSCLC patients (mean age 62) treated at MD Anderson from 2000 to 2017. The researchers included patients with up to three metastatic lesions, but most had one (29%) or two (53%) sites. The brain was the most common site (44%), followed by bone (26%) and the adrenal gland (19%). Most patients had adenocarcinoma (77%) or squamous (18%) histology. In the overall group, 19% had thoracic stage I disease, 22% had stage II disease, and 59% had thoracic stage III disease.
In all, 75% of patients received LCT to their primary lesion, 76% to all distant metastases, and 62% receiving LCT to all disease sites. The vast majority of patients (90%) were also treated with systemic therapy.
Corsini disclosed no relevant relationships with industry.