The standard treatment for patients with early stage non-small cell lung cancer (NSCLC) is surgical resection. Stereotactic body radiotherapy (SBRT) has recently been investigated as an alternative treatment in place of surgery in clinical trials, especially for medically inoperable (MI) patients. However, no clear rationale for the criteria used to determine whether or not a patient is MI has yet been demonstrated.
Between January 2004 and October 2012, 740 patients underwent surgical resection for clinical stage IA NSCLC. In the present study, MI was defined as patients with FEV1.0 ≤ 0.8L, %DLCO 50mmHg, or three or more severe comorbidities, based on the criteria of MI that are frequently used in clinical trials in SBRT for NSCLC patients. The clinicopathological characteristics and surgical outcomes were compared between the MI patients (n = 91) and operable patients (n =649).
The proportion of males, elderly, smokers and those with a non-adenocarcinoma histology were higher in MI patients than in operable patients. No statistical difference was observed in the proportion of pathological stage IA between the groups (P = 0.09). Limited operation (wedge lung resection or segmentectomy) was performed for 37 (41%) MI and 227 (35%) operable patients (P = 0.3). The rates of overall morbidity (39% vs 23%, P = 0.002) and 90-day mortality (3% vs 0.5%, P = 0.03) were higher in the MI patients than those in the operable patients. Although overall survival was significantly worse in the MI patients (P = 0.004), there were no significant differences in cancer-specific survival between the groups (P = 0.5).
Surgical resection can be performed safely in the MI patients with an equivalent cancer-specific survival to that observed in the operable patients. The overall survival was superior to that noted in previously reported clinical trials of SBRT in MI patients with early stage NSCLC. Therefore, the current criteria of MI used in clinical trials of SBRT in NSCLC patients are not appropriate for evaluating the true degree of operability.
Clinical trial identification
Legal entity responsible for the study
The institutional review board of Juntendo University School of Medicine
A Grant-in-Aid for Cancer Research from the Ministry of Health, Labor and Welfare of Japan
All authors have declared no conflicts of interest.