Treatment of stage I lung cancer in high-risk and inoperable patients: comparison of prospective clinical trials using stereotactic body radiotherapy (RTOG 0236), sublobar resection (ACOSOG Z4032), and radiofrequency ablation (ACOSOG Z4033).

OBJECTIVE

The purpose of the present study was to compare the selection criteria and short-term outcomes among 3 prospective clinical trials using stereotactic body radiotherapy (Radiation Therapy Oncology Group [RTOG] trial 0236), sublobar resection (American College of Surgeons Oncology Group [ACOSOG] trial Z4032), and radiofrequency ablation (ACOSOG trial Z4033).

METHODS

The selection criteria and outcomes were compared among RTOG 0236 (n = 55), ACOSOG Z4032 (n = 211), and ACOSOG Z4033 (n = 51). Age, Eastern Cooperative Oncology Group performance status, percentage of predicted forced expiratory volume in 1 second, and percentage of predicted carbon monoxide diffusing capacity of the lung were used to perform a propensity-matched analysis among patients with clinical stage 1A in RTOG 0236 and ACOSOG Z4032.

RESULTS

The patients in ACOSOG Z4033 undergoing radiofrequency ablation were older (75.6 ± 7.5 years) than those in RTOG 0236 (72.5 ± 8.8 years) and ACOSOG Z4032 (70.2 ± 8.5 years; P = .0003). The pretreatment percentage of predicted forced expiratory volume in 1 second was 61.3% ± 33.4% for RTOG 0236, 53.8% ± 19.6% for ACOSOG Z4032, and 48.8% ± 20.3% for ACOSOG Z4033 (P = .15). The pretreatment percentage of predicted carbon monoxide diffusing capacity of the lung was 61.6% ± 30.2% for RTOG 0236, 46.4% ± 15.6% for ACOSOG Z4032, and 43.7% ± 18.0% for ACOSOG Z4033 (P = .001). The overall 90-day mortality for stereotactic body radiotherapy, surgery, and radiofrequency ablation was 0%, 2.4% (5/211), and 2.0% (1/51), respectively (P = .5). Overall, the unadjusted 30-day grade 3+ adverse events were more common with surgery than with stereotactic body radiotherapy (28% vs 9.1%, P = .004), although no difference was between the 2 groups at 90 days. Among the patients with clinical stage IA in ACOSOG Z4032, 29.3% had a more advanced pathologic stage at surgery. A propensity-matched comparison showed no difference between stereotactic body radiotherapy and surgery for 30-day grade 3+ adverse events (odds ratio, 2.37; 95% confidence interval, 0.75-9.90; P = .18).

CONCLUSIONS

Among appropriately matched patients, no difference was seen in early morbidity between sublobar resection and stereotactic body radiotherapy. These results underscore the need for a randomized trial to delineate the relative survival benefit of each modality and to help stratify patients considered high risk.