FROM JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
A study performed to validate the National Surgical Quality Improvement Program (NSQIP) Surgical Risk Calculator for use in patients receiving surgery or stereotactic body radiation therapy (SBRT) for stage I non–small cell lung cancer showed the calculator to be inadequate for both classification and risk stratification. The study was reported in the March issue of the Journal of Thoracic and Cardiovascular Surgery ( 2016;151;697-705 ).
Dr. Pamela Samson of Washington University in St. Louis and her colleagues performed a retrospective analysis of 485 patients with clinical stage I NSCLC who underwent either surgery (277) or SBRT (195) from 2009 to 2012. Surgery was either wedge resection (19.3%) or lobectomy (74.5%), with smaller percentages receiving segmentectomy (4.0%), pneumonectomy (1.5%), and bilobectomy (0.7%). A large majority of surgical patients (84.1%) underwent a video-assisted thoracoscopic surgery (VATS) approach.
The researchers calculated NSQIP complication risk estimates for both surgical and SBRT patients using the NSQIP Surgical Risk Calculator. They compared predicted risk with actual adverse events.
Compared with patients undergoing VATS wedge resection, patients receiving SBRT were older, had larger tumors, lower forced expiratory volume (FEV1) and diffusing capacity of the lungs for carbon monoxide (DLCO), higher American Society of Anesthesiologist scores, higher rates of dyspnea and higher NSQIP serious complication risk estimates, all significant at P less than .05. Similar disparities were seen in comparing patients receiving SBRT vs. VATS lobectomy.
The actual serious complication rate for surgical patients was significantly higher than the NSQIP risk calculator prediction (16.6% vs. 8.8%), as was the rate of pneumonia (6.0% vs. 3.2%), both at P less than .05.
Overall, the NSQIP Surgical Risk Calculator provided a fair level of discrimination between VATS lobectomy and SBRT on receiver operating characteristic (ROC) curve analysis, but it was a poor model for differentiating between VATS wedge resection and SBRT. “Unfortunately, it is this latter population of the highest risk surgical patients (for whom a lobectomy is not a surgical option) where risk models and decision aids are needed most,” Dr. Samson and her colleagues stated.
“Counseling the high-risk but operable patient with clinical stage I NSCLC in regard to lobectomy, sublobar resection, or SBRT is challenging for both the clinician and the patient,” according to the researchers. “We believe that a model tailored to patients with clinical stage I needs to serve as both an estimator of operative risks and a patient decision aid for surgery versus SBRT, especially with projected increases in the number of early-stage lung cancers as a result of increased lung cancer screening efforts,” they added.
“Our analysis suggests that the NSQIP Surgical Risk Calculator likely does not profile the risk of a patient with lung cancer closely enough to dichotomize surgical and inoperable SBRT cases (especially when patients are being considered for a wedge resection) or adequately estimate a surgical patient’s risk of serious complications,” Dr. Samson and her colleagues concluded.
The study was supported by grants from National Institutes of Health. The authors had no relevant financial disclosures.
