Lung Cancer: Do High-Volume Centers Lead to Better Overall Survival?

LOS ANGELES—Treating lung cancer with radiofrequency ablation (RFA) at high-volume centers is linked with improved overall survival, researchers reported in a study presented at the annual meeting of the Society of Interventional Radiology. However, higher T-classification and increasing age were associated with worse overall survival in the setting of RFA for early-stage non small-cell lung cancer (NSCLC) following propensity score-validated analysis.

Although surgery is standard-of-care for early stage NSCLS, not all patients want to undergo an invasive procedure or are candidates for such a procedure. As a result, RFA has become an acceptable alternative option to invasive surgery.

Prior studies have shown that both the volume of patients treated at a center and the demographics of the patients have an impact on survival following surgery for NSCLC. However, the effects of those metrics on survival after RFA have not been thoroughly explored.

For this study, Alexander Huynh Lam, MD, and colleagues retrospectively evaluated data from all patients diagnosed as having NCLC from 2004-2014 in the National Cancer Database. Patients were included if they were treated with RFA and if they had American Joint Committee on Cancer staging 7th edition T1aNOMO and T1bNOMO disease with tumors less than or equal to 3 cm. If patients received chemotherapy or radiotherapy, they were excluded.

The study’s primary outcome was overall survival, while secondary outcomes included length of hospital stay, 30- and 90- day mortality, and unplanned readmission within 30 days following discharge.

To determine significant predictive factors for overall survival, multivariate analysis was used. The Kaplan-Meier method was used to estimate survival probabilities, and differences between survival curves were assessed with log-rank analysis. Propensity score matched cohort analyses adjusted for confounders between significant covariates.

A total of 967 patients were included in the cohort during the study period, and 15 of the initial 305 facilities that performed RFA were designated as high-volume centers. There were 335 patients treated at high-volume centers, which were defined as treating more than 12 patients total during the study period.

After a median follow-up time of 62.5 months, analysis showed that improvement in overall survival was significantly linked with treatment at high-volume centers. Worse overall survival was associated with increasing age and T1b disease.

The significant improvement in overall survival remained even after propensity-score weighted analysis of a matched cohort of 574 cases.

Dr. Lam and colleagues hypothesized that several reasons may have led to the survival benefit at high-volume centers, including the positive effects of the involvement of multidisciplinary specialists.

The study’s limitations include selection bias due to accruing NCDB data from about one-third of hospitals in the United States. Additionally, the registry data used for the study was originally collected for a different purpose.

—Lauren LeBano

Reference

A Lam, E Yoshida, K Bui, et al. Comparison of Ablation at High-Volume Centers with Stereotactic Body Radiation Therapy in Early-Stage Primary Non-Small Cell Carcinoma: A National Cancer Database Study. Presented During SIR 2018. March 18, 2018.