Prediction of Spread Through Air Spaces (STAS) By Intraoperative Frozen Section for Patients with cT1N0M0 Invasive Lung Adenocarcinoma: A Multi-Center Observational Study (ECTOP-1016).

OBJECTIVE: To investigate the value of intraoperative assessment of spread through air spaces (STAS) on frozen sections (FS) in peripheral small-sized lung adenocarcinoma. BACKGROUND: Surgical decision-making based on FS diagnosis of STAS may be useful to prevent local control failure after sublobar resection. METHODS: We conducted a multicenter prospective observational study of consecutive patients with cT1N0M0 invasive lung adenocarcinoma to evaluate the accuracy of FS for the intraoperative detection of STAS. The final pathology (FP) diagnosis of STAS was based on corresponding permanent paraffin sections. RESULTS: This study included 878 patients with cT1N0M0 invasive lung adenocarcinoma. A total of 833 cases (95%) were assessable for STAS on FS. 26.4% of the cases evaluated positive for STAS on FP, whereas 18.2% on FS. The accuracy, sensitivity, and specificity of FS diagnosis of STAS were 85.1%, 56.4%, and 95.4%, respectively, with moderate agreement (κ=0.575). Inter-observer agreement was substantial (κ=0.756) among the three pathologists. Subgroup analysis based on tumor size or consolidation-to-tumor ratio all showed moderate agreement for concordance. After rigorous reassessment of false-positive cases, the presence of artifacts may be the main cause of interpretation errors. Additionally, true positive cases showed more high-grade histological patterns and more advanced p-TNM stages than false negative cases. CONCLUSIONS: This is the largest prospective observational study to evaluate STAS on FS in patients with cT1N0M0 invasive lung adenocarcinoma. FS is highly specific with moderate agreement, but is not sensitive for STAS detection. While appropriately reporting STAS on FS may provide surgeons with valuable information for intraoperative decision-making, better approaches are needed.

Prediction of the pathological subtypes by intraoperative frozen section for patients with cT1N0M0 invasive lung adenocarcinoma (ECTOP-1015): a prospective multicenter study.

BACKGROUND: This study aims to assess the diagnostic accuracy of the intraoperative frozen section (FS) in determining the pathological subtypes among patients diagnosed with cT1N0M0 invasive lung adenocarcinoma. MATERIALS AND METHODS: This was a prospective, multicenter (seven centers in China) clinical trial of Eastern Cooperative Thoracic Oncology Projects (ECTOP-1015). Patients with cT1N0M0 invasive lung adenocarcinoma were enrolled in the study. Pathological images obtained from FS and final pathology (FP) were reviewed by at least two pathologists. The primary endpoint was the concordance between FS and FP diagnoses. The interobserver agreement for identifying pathological subtypes on FS was evaluated among three pathologists. RESULTS: A total of 935 patients were enrolled. The best sensitivity of diagnosing the predominant subtype was 78.2% in the evaluation of the acinar pattern. The presence of an acinar pattern diagnosed by FS was an independent factor for the concordance between FS and FP ( P =0.007, 95% confidence interval: 2.332-4.736). Patients with tumor size >2 cm measured by pathology showed a better concordance rate for the predominant subtype (81.6% vs. 74.6%, P =0.023). The presence of radiological ground glass opacity component did not affect the diagnosis accuracy of FS for the predominant subtype (concordance rate: 76.4% vs. 75.2%, P =0.687). Patients with ground glass opacity component showed better accuracy of the identification in the presence of lepidic pattern-predominant adenocarcinoma (82.1% vs. 71.0%, P =0.026). Substantial agreement between the FS diagnosis from three pathologists for the predominant pathological pattern was revealed with κ=0.846. CONCLUSIONS: This is the largest prospective trial evaluating FS diagnosing pathological subtype in cT1N0M0 invasive lung adenocarcinoma. A favorable concordance in the assessment of the pathological subtypes between FS and FP was observed, indicating the feasibility of utilizing accurate intraoperative pathological diagnoses from FS in guiding surgical strategies. A combination of radiology could improve the precision of FS.

Systemic immune index predicts tumor-infiltrating lymphocyte intensity and immunotherapy response in small cell lung cancer.

Background: Despite recent progresses in immune checkpoint blockade (ICB) in small-cell lung cancer (SCLC), a lack of understanding regarding the systemic tumor immune environment (STIE) and local tumor immune microenvironment (TIME) makes it difficult to accurately predict clinical outcomes and identify potential beneficiaries from ICB therapy. Methods: We enrolled 191 patients with stage I-III SCLC and comprehensively evaluated the prognostic role of STIE by several quantitative measurements, and further integrate it with a local immune score system (LISS) established by eXtreme Gradient Boosting (XGBoost) machine learning algorithm. We also test the value of STIE in beneficiary selection in our independent advanced SCLC cohort receiving programmed cell death 1 ligand 1 (PD-L1) blockade therapy. Results: Among several systemic immune markers, the STIE as assessed by prognostic nutritional index (PNI) was correlated with disease-free survival (DFS) and overall survival (OS), and remained as an independent prognostic factor for SCLC patients [hazard ratio (HR): 0.473, 95% confidence interval (CI): 0.241-0.929, P=0.030]. Higher PNI score was closely associated with inflamed SCLC molecular subtype and local tumor-infiltrating lymphocytes (TILs). We further constructed a LISS which combined top three important local immune biomarkers (CD8+ T-cell count, PD-L1 expression on CD8+ T-cell and CD4+ T-cell count) and integrated it with the PNI score. The final integrated immune risk system was an independent prognostic factor and achieved better predictive performance than Tumor Node Metastasis (TNM) stages and single immune biomarker. Furthermore, PNI-high extensive-stage SCLC patients achieved better clinical response and longer progression-free survival (PFS) (11.8 vs. 5.9 months, P=0.012) from PD-L1 blockade therapy. Conclusions: This study provides a method to investigate the prognostic value of overall immune status by combining the PNI with local immune biomarkers in SCLC. The promising clinical application of PNI in efficacy prediction and beneficiary selection for SCLC immunotherapy is also highlighted.

Excellent survival of pathological N0 small cell lung cancer patients following surgery.

BACKGROUND: Current clinical guidelines recommend surgery only for cT1-2N0M0 small cell lung cancer (SCLC) patients. In light of recent studies, the role of surgery in the treatment of SCLC needs to be reconsidered. METHODS: We reviewed all SCLC patients who underwent surgery from November 2006 to April 2021. Clinicopathological characteristics were retrospectively collected from medical records. Survival analysis was performed by the Kaplan-Meier method. Independent prognostic factors were evaluated by Cox proportional hazard model. RESULTS: 196 SCLC patients undergoing surgical resection were enrolled. The 5-year overall survival for the entire cohort was 49.0% (95% CI: 40.1-58.5%). PN0 patients had significantly superior survival to pN1-2 patients (p < 0.001). The 5-year survival rate of pN0 and pN1-2 patients were 65.5% (95% CI: 54.0-80.8%) and 35.1% (95% CI: 23.3-46.6%), respectively. Multivariate analysis revealed that smoking, older age, and advanced pathological T and N stages were independently associated with poor prognosis. Subgroup analyses demonstrated similar survival among pN0 SCLC patients regardless of pathological T stages (p = 0.416). Furthermore, multivariate analysis showed factors, including age, smoking history, type of surgery, and range of resection, were not independently prognostic factors for the pN0 SCLC patients. CONCLUSION: Pathological N0 stage SCLC patients have significantly superior survival to pN1-2 patients, regardless of features, including T stage. Thorough preoperative evaluation should be applied to estimate the status of lymph node involvement to achieve better selection of patients who might be candidate for surgery. Studies with larger cohort might help verify the benefit of surgery, especially for T3/4 patients.