Survival Increased with Value-Added Stereotactic Body Radiation Therapy in Patients with Lung Cancer

October 2016, Vol 7, No 9

Boston, MA—Stereotactic body radiation therapy (SBRT) dramatically improves survival in patients with early-stage non–small-cell lung cancer (NSCLC), including elderly patients, as demonstrated by 2 large studies presented at the 2016 American Society for Radiation Oncology (ASTRO) annual meeting by Andrew M. Farach, MD, Houston Methodist Hospital, TX, and Matthew J. Boyer, MD, PhD, Radiation Oncology at Duke University Medical Center, Durham, NC, respectively.

In the first study, survival improved by approximately 20% during the past decade in elderly patients with NSCLC who received SBRT. The second study showed that SBRT doubled the 4-year survival rates in patients with early-stage lung cancer who were treated at Veterans Health Administration (VHA) facilities.

At the press conference where these data were presented, session moderator Brian D. Kavanagh, MD, MPH, FASTRO, President-Elect of ASTRO, and Chair, Department of Radiation Oncology, University of Colorado Denver, Aurora, said that SBRT represents a value-added treatment, keeping in theme with this year’s ASTRO meeting, “Enhancing Value, Improving Outcomes.”

“What we might be observing in these studies is better outcomes for a treatment with higher value. SBRT is a smarter, more efficient way to deliver therapy, with fewer visits and shorter treatment time that is easier for patients to take. This connects with value,” Dr Kavanagh commented. “It is pretty rare in medicine to see this dramatic improvement over such a short period of time,” he added.

SEER Database of Elderly Patients with NSCLC

SBRT delivers a highly targeted, escalated dose of radiation over a shorter period compared with conventional radiation, and has been widely adopted as the definitive primary treatment for elderly patients, who often have multiple comorbidities that render them unfit for surgery.

“Our findings indicate that physicians should feel confident recommending SBRT to patients who are too sick to undergo surgery or who chose not to undergo surgery for other reasons,” said Dr Farach.

Coinciding with widespread adoption of SBRT over the past decade, overall survival (OS) at 23 months increased by 19% over the study period (2004-2012), and cancer-specific survival increased by 24% in these older patients with early-stage NSCLC.

The study was based on records of 62,213 patients aged ≥60 years and diagnosed with stage I NSCLC between 2004 and 2012 included in the National Cancer Institute’s SEER database. Of these, 41,509 were treated with surgery only, 11,589 received radiation only, and 7373 received no treatment.

“The records show that the majority of younger patients with early-stage lung cancer age 60 to 64 get surgery, but with age, there is a dramatic drop off until it reaches 21% in patients 80 and older,” Dr Farach said. “Radiation replaces surgery in older patients,” he added.

In patients receiving SBRT, 23-month survival rates rose by approximately 20%: 39% in 2004 to 58% in 2012 (P <.001). The 23-month OS rates for surgery alone rose only 5% during that time, from 79% to 84%. No survival improvement was reported for untreated patients.

Over the same time, cancer-specific survival increased from 48% to 72% in patients treated with SBRT alone (P <.001) and from 87% to 91% in patients receiving surgery alone (P <.001). Cancer-specific survival rates improved slightly for patients who received neither surgery nor radiation.

Veterans Health Administration Study

The survival rates of patients with early-stage NSCLC doubled from 2002 to 2012 with the use of SBRT rather than conventional radiation therapy, according to a study of patients treated at VHA hospitals.

“When we started this analysis, there were no direct comparisons of these techniques. Outcomes are better with SBRT. The increased use of SBRT is strongly associated with improved survival. These findings...are generalizable to patients outside the VHA,” said lead investigator Dr Boyer.

The Veterans Affairs Central Cancer Registry was cross-referenced with the Veterans Affairs Corporate Data Warehouse from 2001 through 2010 to identify patients with clinical stage I NSCLC who were treated with conventional radiation or SBRT. Of 14,177 patients, 3012 were treated with radiation: 1203 with conventional radiation, and 468 with SBRT. The median age was 72 years.

Improved survival was associated with increased use of SBRT over the study period. In 2001, the first year of the study, 95% of patients who received radiation had conventional radiation therapy. By 2010, 60% of patients treated with radiotherapy received SBRT.

The 4-year OS increased by approximately 16%, and the 4-year lung cancer–specific survival increased by approximately 17%. The OS was 18.8% with conventional radiation versus 37.0% with SBRT. Lung cancer–specific survival was 28.3% versus 53.2% for patients treated with conventional radiation and SBRT, respectively.

“We were surprised by the magnitude of improvement in our study. Other studies have suggested an improvement with SBRT. At our institution, no one with stage I NSCLC is getting conventional radiation. SBRT is the standard across the board,” said Dr Boyer.

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