Stereotactic ablative radiotherapy provided long-term tumor control and increased OS and PFS among patients with early-stage multiple primary lung cancer, according to study results.
Multiple primary lung cancer incidence has increased steadily in recent years. Although surgical resection has been the standard form of treatment, many patients are unable to undergo surgery, according to background information provided by researchers.
Joe Y. Chang
Joe Y. Chang, MD, PhD, of the department of radiation oncology at The University of Texas MD Anderson Cancer Center, and colleagues examined the use of stereotactic ablative radiotherapy in 101 patients (57% men) with multiple primary lung cancer.
Median patient age at diagnosis was 72 years (range, 50-90 years).
Tumors were treated with stereotactic ablative radiotherapy 50 Gy in four fractions (n=120) or 70 Gy in 10 fractions (n=10).
Median OS was 46 months. Overall, researchers reported OS rates of 73.2% at 2 years and 47.5% at 4 years; PFS rates of 67% at 2 years and 58% at 4 years; and infield local control rates of 97.4% at 2 years and 95.7% at 4 years.
Patients with metachronous tumors demonstrated improved survival compared with those who had synchronous tumors.
At 2 years, OS rates were 80.6% for patients with metachronous tumors vs. 61.5% for patients with synchronous tumors. PFS rates were 84.7% for metachronous vs. 49.4% for synchronous.
At 4 years, OS rates were 52.7% for metachronous tumors vs. 39.7% for synchronous tumors. PFS rates were 75.6% for metachronous tumors vs. 30.4% for synchronous tumors.
Grade ≥3 radiation pneumonitis occurred in 3% of patients who underwent surgery or received stereotactic ablative radiotherapy for an index tumor. The incidence increased to 17% for patients who received conventional radiotherapy for an index tumor. Other grade ≥3 toxicities were chest wall pain (3%) and skin toxicity (1%).
“Stereotactic ablative radiotherapy achieves promising long-term tumor control and survival and may be a potential curative treatment for early-stage multiple primary lung cancer,” Chang and colleagues concluded.
Disclosure: The researchers report no relevant financial disclosures.