SBRT as Effective Treatment Option for Medically Operable Stage I NSCLC

Summary

This retrospective nonrandomized analysis demonstrated no significant difference in overall survival between patients with stage I non–small cell lung cancer who were treated with the traditional surgical approach compared with medically operable patients who refused surgery, were older, and opted for stereotactic body radiation therapy because of its high control rates and low toxicity.

  • early stage lung cancer
  • stage I non–small cell lung cancer
  • stereotactic body radiation therapy
  • overall survival
  • oncology clinical trials

A surgical lobectomy, or segmental, wedge, or sleeve resection, is the primary treatment option for patients with stage I (T1-2aN0M0) non–small cell lung cancer (NSCLC) [National Cancer Institute. http://www.cancer.gov/cancertopics/pdq/treatment/non-small-cell-lung/healthprofessional/page7. Accessed April 22, 2014]. However, in patients with medically inoperable tumors, stereotactic body radiation therapy (SBRT) is a safe and effective treatment option conferring local control in > 90% of patients [Timmerman R et al. JAMA. 2010]. An international study of SBRT that reported high rates of local control, low toxicities, and favorable overall survival (OS) in this patient population has led to a recent increase in the number of patients with medically operable early stage NSCLC who prefer this treatment over surgery [Grills IS et al. J Thorac Oncol. 2012].

Although no randomized trial comparing SBRT with surgery has been reported to date, in an attempt to indirectly address this question, Maddalena Rossi, PhD, The Netherlands Cancer Institute, Amsterdam, The Netherlands, and colleagues compared OS within a large cohort of patients with medically operable stage I NSCLC who refused surgery and opted for SBRT with those patients who were surgically treated [Rossi M et al. Ann Oncol. 2015].

This nonrandomized retrospective analysis included all patients from 2006 to 2012 who presented with peripheral stage I (T1-T2a) NSCLC to the Netherlands Cancer Institute. Patients with synchronous lung tumors or prior SBRT were excluded. Volumetric image guided radiation therapy was used for verifying tumor position and setup with SBRT (18Gy 3 times within 8-11 days). Patients were excluded from the surgical cohort if they had received chemotherapy prior to or after surgery. The log-rank test for significance was used to compare OS in the SBRT vs surgery groups.

After excluding ineligible patients for this retrospective study, of 517 patients receiving SBRT, 42 patients with medically operable NSCLC had refused surgery. The median follow-up for this SBRT group was 24.2 months (range, 3-85 months). The average age of this 50% male SBRT cohort was 74.2 years with 83% of patients identified as stage T1 and 17% as stage T2a. The 66 patients identified in the surgical cohort (who did not receive SBRT) had a median follow-up of 29.5 months (range, 1-88 months). The average age of this 45% male surgical group was 63.9 years with 78% of patients identified as stage T1 and 22% as stage T2a.

The OS of the SBRT cohort at 1 year (97.0%; 95% CI, 92.0 to 100), 3 years (79.0%; 95% CI, 66.0 to 96.0), and 5 years (72.2%; 95% CI, 55.3 to 94.3) was not significantly different (log-rank P = .31) from the surgical cohort at 1 year (93.6%; 95% CI, 88.0 to 100), 3 years (80.6%; 95% CI, 70.0 to 92.0), and 5 years (46.2%; 95% CI, 30.5 to 69.6), respectively.

Based on the results of this retrospective analysis, Rossi and colleagues concluded that despite the higher age of the SBRT ‘surgery refusal’ cohort compared with the surgical cohort (74.2 years vs 63.9 years), OS after SBRT in patients with peripherally located stage I NSCLC was not significantly different.

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