No Improvement in Local Recurrence With Brachytherapy After Sublobar Resection in Patients With High-Risk Stage I NSCLC
In the phase III American College of Surgeons Oncology Group (ACOSOG) Z4032/Alliance trial reported in the Journal of Clinical Oncology, Fernando et al found that adjuvant brachytherapy did not improve risk for local recurrence after sublobar resection in patients with high-risk stage I operable non–small cell lung cancer (NSCLC).
Study Details
In the trial, 222 patients with high-risk NSCLC ≤ 3 cm were randomly assigned to receive sublobar resection with (n = 108) or without (n = 114) brachytherapy. The primary endpoint was time to local recurrence in the intent-to-treat population, including recurrence at the staple line (local progression), in the primary tumor lobe away from the staple line, and in ipsilateral hilar nodes.
The brachytherapy and control groups were generally balanced for age (median, 72 and 70 years), sex (55% and 57% female), Eastern Cooperative Oncology Group performance status (0 in 23% and 17%, 1 in 56% and 58%, 2 in 21% and 25%), clinical nodule size (≤ 2 cm in 62% and 64%), stage (T1 in 96% and 100%), American Society of Anesthesiology class (III/IV in 79% and 91%, P = .02), baseline FEV1 (median, 53% and 48%), and baseline DLCO (median, 45% and 47%).
Local Recurrence Rates
Median follow-up was 4.4 years. At 5 years, local recurrence rates were 16.7% in the brachytherapy group vs 14.0% in the control group (P = .59), with no significant difference in time to local recurrence (hazard ratio [HR] = 1.01, P = .98). Local progression occurred in only 17 patients (8% of entire population). Local recurrence rates were 9.3% vs 12.3% (P = .47) at 2 years and 12.0% vs 12.3% at 3 years (P = .96)
Nonsignificant trends in local recurrence favored the brachytherapy group among those patients with potentially compromised surgical margins (margin < 1 cm, margin-to-tumor ratio < 1, positive staple line cytology, wedge resection, nodule size > 2.0 cm), particularly among the 14 patients with positive staple line cytology (HR = 0.22, P =.24).
Overall survival rates were 71.3% vs 71.1% at 3 years (P = .97) and 55.6% vs 61.4% at 5 years (P = .38).
The investigators concluded, “Brachytherapy did not reduce [local recurrence] after [sublobar resection]. This finding may have been related to closer attention to parenchymal margins by surgeons participating in this study.”
Hiran C. Fernando, MD, of Boston Medical Center, is the corresponding author for the Journal of Clinical Oncology article.
The study was supported by grants from the National Cancer Institute and by Oncura. For full disclosures of the study authors, visit jco.ascopubs.org.
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