Median overall survival increased significantly among patients with stage I non–small cell lung cancer over the last decade – in particular, those treated with radiation therapy alone, according to an analysis of the Surveillance, Epidemiology, and End Results database.
The median survival for all treatment groups increased by 27%, from 44 months during 1999-2003 to 56 months during 2004-2008. For those treated with radiation alone – who would likely be the sickest patients since they would not have been considered candidates for surgery – median overall survival improved by 31%, from 16 to 21 months. Both changes were statistically significant (log rank P less than .0001).
"Stage I NSCLC [non–small cell lung cancer] patients who receive radiation therapy alone are surviving longer than they used to," Dr. Nirav S. Kapadia said in a press briefing from the Chicago Multidisciplinary Symposium in Thoracic Oncology.
A change in the survival of patients treated with surgery could not be detected, as median survival has not yet been reached, he and his coauthors reported.
Until recently, surgery has been the primary treatment for stage I NSCLC. However, as recent advances in radiotherapy (RT) such as stereotactic body radiation therapy have allowed dose escalation with more precise tumor targeting, the use of RT has increased, and outcomes appear to have improved over time, said Dr. Kapadia, a chief resident in the department of radiation oncology at the University of Michigan, Ann Arbor
The National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) database encompasses about 25% of the U.S. population. This study compared SEER data on 27,469 patients with NSCLC treated during 1999-2003 with data from 26,195 patients treated during 2004-2008.
During 1999-2003, 64% of patients were treated with primary surgery, 14% received RT alone, 20% had neither treatment, and 2% had unknown treatment. In the later era, 70% of patients underwent primary surgery, 13% received primary RT, 16% had neither surgery nor RT, and 1% had unknown treatment.
The proportion receiving surgery alone increased from 60% to 67% during the two time periods. Thus, the rates of surgery increased from the earlier to the later period, but there was no significant difference in the number of patients who received radiotherapy, either as an adjunct to surgery or as definitive therapy, noted Dr. Kapadia.
He expressed concern about the significant proportion of patients – 20% in the earlier period and 16% in the later – who did not receive surgery or radiation. "At least 16% of patients are still not getting the care that they need – care that could save their lives. We must identify the barriers to treatment so that every patient has hope for a cancer cure," he said in a statement.
For the entire study period, factors significantly associated with higher risk of death after primary RT or surgery included age, African American race, large cell or squamous histology, and being unmarried. Significant protective factors included female sex and race listed as "other."
Dr. Kapadia noted that RT is advantageous in that it is noninvasive and is done on an outpatient basis. Moreover, local control rates with radiotherapy among patients who are too sick to undergo surgery are now approaching those of surgery.
Ongoing "coin flip" studies are currently comparing outcomes of radiation versus surgery in patients who would otherwise be fit for surgery. "Those are going to be very exciting studies. ... But for right now I would say surgery is still the preferred modality, with a large body of evidence to support that statement," he said.
The symposium was sponsored by the American Society of Clinical Oncology, the American Society for Radiation Oncology, the International Association for the Study of Lung Cancer, and the University of Chicago.