Stage IV lung cancer patients whose cancer has spread to a limited number of sites can live longer if they receive radiation therapy (RT) or surgery in addition to systemic therapy, according to research presented at the American Society for Radiation Oncology (ASTRO) conference in San Antonio.
"We found that adding radiation or surgery to target all sites of disease increases the time it takes for the cancer to return or spread, and it also improves overall survival time," said Dr. Daniel Gomez of MD Anderson Cancer Center in a statement from ASTRO. "But the overall survival results were more impressive than anticipated."
The study followed up on prior research published in 2016 in Lancet Oncology that showed encouraging results for progression-free survival from aggressive local therapy -- RT or surgery -- over a median follow-up period of just over a year. It included patients from three hospitals (MD Anderson Cancer Center, London Health Sciences Center, and the University of Colorado) who had stage IV non-small cell lung cancer that had spread to no more than three sites. All patients received systemic therapy; those whose cancers did not progress following first-line treatment were randomized into one of the following: an experimental arm of 25 patients who received surgery or RT at the tumor site or a group of 24 patients who received standard systemic maintenance therapy and observation.
The new results presented at ASTRO 2018 included updated progression-free survival data, as well as overall survival and toxicity data over a median 38.8 months of follow-up. The researchers found that patients in the experimental arm of the study experienced a progression-free survival benefit of 14.2 months, compared with 4.4 months for those who received standard treatment and observation. The different was statistically significant (p = 0.014).
What's more, the patients who received radiation or surgery experienced a median overall survival rate of 41.2 months, compared with 17 months for those who received standard maintenance therapy and observation. That difference was also statistically significant (p = 0.017).
"This is a very long overall survival time for patients with metastatic disease," Gomez said.
No additional severe toxicities were reported in either treatment arm other than those previously described, according to the researchers.
In other findings, the time before a new lesion appeared was a median of 14.2 months for patients treated with radiation or surgery, compared with six months for those in the standard maintenance therapy and observation arm. That difference approached statistical significance (p = 0.11).
Ongoing phase II/III trials will continue to assess the effect of local consolidative therapy in larger populations with the addition of immunotherapy and targeted drug therapy.
