Beyond Margin Status: Population-Based Validation of the Proposed International Association for the Study of Lung Cancer Residual Tumor Classification Recategorization.

INTRODUCTION: The International Association for the Study of Lung Cancer's (IASLC's) proposal to recategorize the residual tumor (R) classification for resected NSCLC needs validation. METHODS: Using a 2009 to 2019 population-based multi-institutional NSCLC resection cohort from the United States, we classified resections by Union for International Cancer Control (UICC) and IASLC R criteria and compared the distribution of R classification variables and their survival associations. RESULTS: Of 3361 resections, 95.3% were R0, 4.3% were R1, and 0.4% were R2 by UICC criteria; 33.3% were R0, 60.8% were R-uncertain, and 5.8% were R1/2 by IASLC criteria; 2044 patients (63.8%) migrated from UICC R0 to IASLC R-uncertain. Median survival was not reached, 69 (95% confidence interval [CI]: 64-77), and 25 (95% CI: 18-36) months, respectively, for patients with IASLC R0, R-uncertain, and R1 or R2 resections. Failure to achieve nodal dissection criteria caused 98% of migration to R-uncertainty, metastasis to the highest mediastinal node station, 5.8%. Compared with R0, R-uncertain resections with mediastinal nodes, no mediastinal nodes, and no nodes had adjusted hazard ratios of 1.28 (95% CI: 1.10-1.48), 1.47 (95% CI: 1.24-1.74), and 1.74 (95% CI: 1.37-2.21), respectively, suggesting a dose-response relationship between nodal R-uncertainty and survival. Accounting for mediastinal nodal involvement, the highest mediastinal station involvement was not independently prognostic. The incomplete resection variables were uniformly prognostic. CONCLUSIONS: The proposed R classification recategorization variables were mostly prognostic, except the highest mediastinal nodal station involvement. Further categorization of R-uncertainty by severity of nodal quality deficit should be considered.

Invasive mediastinal staging for resected non-small cell lung cancer in a population-based cohort.

OBJECTIVES: Invasive mediastinal nodal staging is recommended before curative-intent resection in patients with non-small cell lung cancer deemed at risk for mediastinal lymph node involvement. We evaluated the use and survival effect of preoperative invasive mediastinal nodal staging in a population-based non-small cell lung cancer cohort. METHODS: We analyzed all curative-intent resections for non-small cell lung cancer from 2009 to 2018 in 11 hospitals in 4 contiguous Dartmouth Hospital Referral Regions, comparing patients who did not have invasive mediastinal nodal staging with those who did. RESULTS: Preoperative invasive nodal staging was used in 22% of 2916 patients, including mediastinoscopy only in 13%, minimally invasive procedures only in 6%, and both approaches in 3%. Sixty-three percent of patients at risk for nodal disease (tumor size ≥3.0 cm/T2-T4; N1-N3 by computed tomography or positron-emission tomography-computerized tomography criterion) did not undergo invasive staging; among those who did not have invasive testing, 47% had at least 1 of the 3 clinical indications. Mediastinoscopy yielded a median of 3 lymph nodes and 2 nodal stations; 17% of mediastinoscopies and 31% of endobronchial ultrasound procedures yielded no lymph node material. Patients not invasively staged were more likely to have no nodes (6% vs 2%; P < .0001) and no mediastinal nodes (20% vs 11%; P < .0001) examined at surgery. Invasive staging was associated with significantly better survival (P = .0157). CONCLUSIONS: More than a decade after the 2001 American College of Surgeons Patient Care Evaluation report, preoperative invasive nodal staging remains underused and of variable quality, but was associated with survival benefit in high-risk patients.

Survival Before and After Direct Surgical Quality Feedback in a Population-Based Lung Cancer Cohort.

BACKGROUND: Surgical resection is the main curative modality for non-small cell lung cancer (NSCLC), but variation in the quality of care contributes to suboptimal survival rates. Improving surgical outcomes by eliminating quality deficits is a key strategy for improving population-level lung cancer survival. We evaluated the long-term survival effect of providing direct feedback on institutional performance in a population-based cohort. METHODS: The Mid-South Quality of Surgical Resection cohort includes all NSCLC resections at 11 hospitals in four contiguous Dartmouth Hospital Referral Regions in Arkansas, Mississippi, and Tennessee. We evaluated resections from 2004 to 2013, before and after onset of a benchmarked performance feedback campaign to surgery and pathology teams in 2009. RESULTS: We evaluated 2,206 patients: 56% preintervention (pre-era) and 44% postintervention (post-era). Preoperative positron emission tomography/computed tomography (46% vs 82%, p < 0.0001), brain scans (6% vs 21%, p < 0.0001), and bronchoscopy (8% vs 27%, p < 0.0001) were more frequently used in the post-era. Patients had 5-year survival of 47% (44% to 50%) in the pre-era compared with 53% (50% to 56%) in the post-era (p = 0.0028). The post-era had an adjusted hazard ratio of 0.85 (95% confidence interval [CI], 0.75 to 0.97; p = 0.0158) compared with the pre-era. This differed by extent of resection (p = 0.0113): compared with the pre-era, the post-era adjusted hazard ratio was 0.49 (95% CI, 0.33 to 0.72) in pneumonectomy, 0.91 (95% CI, 0.79 to 1.05) in lobectomy/bilobectomy, and 0.85 (95% CI, 0.63 to 1.15) in segmentectomy/wedge resections. CONCLUSIONS: Overall survival after surgical resection improved significantly in a high lung cancer mortality region of the United States. Reasons may include better selection of patients for pneumonectomy and more thorough staging.