The widespread adoption of stereotactic body radiation therapy to treat elderly patients with early-stage non–small cell lung cancer has improved survival rates, according to retrospective, population-based study results presented at the ASTRO Annual Meeting.
Stereotactic body radiation therapy — which delivers highly targeted, escalated radiation in one to five sessions — has become the standard of care for patients with inoperable early-stage NSCLC. In particular, its adoption has increased in elderly patients, who often have comorbidities that limit surgical options.
Andrew M. Farach
“Since 2004, we’ve seen a dramatic increase in the adoption of stereotactic body radiation therapy in the community — with only academic centers providing stereotactic body radiation therapy in 2004, to now, where pretty much all cancer centers have the ability to deliver this significantly improved treatment modality with cancer control outcomes,” Andrew M. Farach, MD, physician in the department of radiation oncology at Houston Methodist Hospital, said during a press conference.
To assess how this increased use correlated with treatment outcomes, Farach and colleagues used the SEER database to identify 62,213 patients aged 60 years or older diagnosed with stage I NSCLC from 2004 to 2012.
The researchers determined how rates of OS and cancer-specific survival changed as the use of stereotactic body radiation therapy increased. They also compared outcomes between stereotactic body radiation and surgery.
In total, 41,509 patients underwent surgery, 11,589 patients were treated with stereotactic body radiation therapy and 7,373 patients received no therapy.
The use of surgery to treat patients with early-stage NSCLC declined with age; 81% of patients aged 60 to 64 years underwent surgery compared with only 47% of patients aged 80 years or older and 21% of patients aged 90 years or older.
Conversely, the use of radiotherapy in these patients increased with age, from 11% of patients aged 60 to 64 years to 39% of patients aged 90 years or older (P < .001).
In addition, the use of no therapy increased from 7% of patients aged 60 to 64 years to 40% of patients aged 90 years and older.
Rates of 23-month OS rose from 39% in 2004 to 58% in 2012 (P < .001) among patients who received stereotactic body radiation therapy, whereas OS rates in patients who received surgery alone increased from 79% to 84% during that time (P < .001). Researchers observed no survival improvement in patients who did not receive radiation or surgery (28% vs. 33%).
Similarly, cancer-specific survival increased from 48% to 72% (P < .001) among patients who received stereotactic body radiation therapy alone, compared with an increase from 87% to 91% (P < .001) among patients who received surgery alone. The increase among patients who did not receive radiation or surgery did not reach statistical significance (38% vs. 45%).
“Our findings indicate that physicians should feel confident recommending radiation therapy to patients who are too sick to undergo surgery or who choose not to undergo surgery for other reasons,” Farach said in a press release. “With continued adoption of stereotactic body radiation therapy in community cancer centers, it is our hope that more patients will receive curative stereotactic body radiation therapy and the number of patients left untreated based on age or medical comorbidity will continue to fall.”
Despite improvements in OS and cancer-specific survival over time, patients who received surgery achieved superior survival rates compared with patients who received stereotactic body radiation therapy. The researchers acknowledged this difference may be partially explained by a selection bias, where healthier patients were treated with surgery, as well as by instances of palliative stereotactic body radiation therapy or conventional radiotherapy.
“While survival rates remain highest for surgical candidates, this study demonstrates both clear benefits from stereotactic body radiation therapy for nonsurgical NSCLC patients and that outcomes following radiation therapy have improved at a more accelerated pace over the past decade than those for any other therapeutic approach,” Farach said in the release.
A controlled clinical trial with matched patients receiving each treatment as a first-line therapy is needed to compare efficacy between surgery and stereotactic body radiation, according to the researchers.
“It’s a rare situation where the more convenient therapy is also the more effective therapy,” he said during the press conference. “Stereotactic body radiation therapy may now help to improve access to care for elderly patients who may in the past have found it very difficult to come for 6 weeks of daily radiation treatment.”– by Kristie L. Kahl
Dalwadi SM, et al. Abstract 152. Presented at: ASTRO Annual Meeting; Sept. 26-28, 2016; Boston.
Disclosure: HemOnc Today could not confirm the researchers’ relevant financial disclosures at the time of reporting.