Liz Meszaros, MDLinx | February 21, 2019
Stereotactic ablative body radiation therapy (SBRT)—currently the standard of care for patients with early-stage non-small-cell lung cancer (NSCLC) who are deemed medically inoperable—may be an alternative to lobectomy (LOB) in patients with medically operable or inoperable stage I-II NSCLC. Advantages of SBRT include both good tolerability and comparable locoregional control, according to a recent study published in Clinical Lung Cancer.
“Patients deemed fit for surgery had a clinical outcome that was comparable with surgery (as well in terms of [overall survival] OS and [progression-free survival] PFS). These findings may suggest that, for operable patients, SBRT and LOB may be considered efficient, effective, and safe alternative options in a real practice scenario,” wrote these authors, led by Vieri Scotti, MD, assistant, Department of Oncology, Radiation Therapy Unit, Careggi University Hospital, Florence, Italy.
In this retrospective analysis, Dr. Scotti and fellow researchers compared LOB and SBRT outcomes in patients with stage I-II NSCLC. They included 187 patients with clinical-stage T1a-T2bNoMo NSCLC who were treated at two academic hospitals. Patients treated with SBRT were also classified as surgical (n=30) or nonsurgical candidates (n=63), depending on any comorbidities or contraindications to surgery.
Notably, patients who underwent LOB were significantly younger than those treated with SBRT (mean age: 67.9 vs 76.6 years, respectively; P < 0.0001). Higher Global Initiative for Chronic Obstructive Lung Disease (GOLD) scale classes were seen at baseline in patients scheduled to undergo SBRT, especially among the nonsurgical candidates. Patients in the LOB group had significantly better Eastern Cooperative Oncology Group Performance Status (ECOG PS) scores at diagnosis compared with those in the SBRT group (P < 0.0001). Adenocarcinoma (59.3%) and squamous cell carcinoma (27.2%) were the most common histological subtypes.
Patients were followed for a median of 23 months, during which time 12 local failures occurred (SBRT: 9, LOB: 3). Upon univariate analysis, Dr. Scotti and colleagues found no significant differences in local control between the two groups, with a trend in favor of surgery (HR: 0.27; 95% CI: 0.07-1.01; P < 0.053). Upon multivariate analysis, they identified surgery and disease stage as independent factors affecting local control (P < 0.042 and P < 0.015, respectively).
Distant metastases occurred in 23% of patients (SBRT: 24; LOB: 19). Researchers found no association between distant failures and surgery, histology, and cancer stage.
Three-year OS was significantly better in patients undergoing LOB compared with SBRT (73.4% vs 65.2%, respectively; HR: 0.44; 95% CI: 0.23-0.85; P < 0.01). Dr. Scotti and fellow researchers found no differences, however, in OS between operable patients undergoing SBRT and those who underwent LOB (HR: 1.68; 95% CI: 0.72-3.90). Inoperable patients had a significantly lower OS compared with those who underwent LOB (HR: 2.76; 95% CI: 1.35-5.68).
Neither gender, histology, T dimension, clinical stage, or GOLD score affected OS. A higher risk of mortality occurred in patients with an ECOG PS score of 2 (HR: 4.05; 95% CI: 1.77-9.26). Patients with an ECOG PS score of 2 had a significantly poorer OS compared with a score of 0 or 1 (53.3% vs 81.1% vs 64.9%, respectively).
Finally, progression-free survival was similar in SBRT and LOB groups (HR: 0.61; P=0.09) with a 3-year PFS of 65.8% and 46.9%, respectively (P < 0.08). PFS was not affected by gender, histology, cT stage, or GOLD class. Again, patients with a PS of 2 had significantly lower PFS (HR: 3.66; 95% CI: 1.60-8.36).
Dr. Scotti and colleagues concluded that “SBRT might lead to the same optimal locoregional control provided by surgery for both operable and inoperable patients with early-stage NSCLC. Moreover, these results support the consideration of SBRT as a valid therapeutic approach in early-stage NSCLC, awaiting data from randomized trials such as the SABRTooth and LUSTRE projects.”