Clinical and Pathologic Differences between Small-Cell Carcinoma and Large-Cell Neuroendocrine Carcinoma of the Lung.

BACKGROUND: Both small-cell carcinoma (SCLC) and large-cell neuroendocrine carcinoma (LCNEC) of the lung are often clinically dealt with as being in the same category as neuroendocrine carcinoma, and their clinical differences have not been adequately assessed. METHODS: The postoperative prognosis was retrospectively analyzed using the data of 196 patients who underwent resection for SCLC or LCNEC. RESULTS: Of the patients included, 99 (50.5%) had SCLC and 97 (49.5%) had LCNEC. The median duration of follow-up was 39 months (interquartile range [IQR] 21-76) and 56 months (IQR 21-87) for SCLC and LCNEC, respectively. The estimated 5-year overall survival (OS) probabilities were 53.7% and 62.7% (p = 0.133) for patients with SCLC and LCNEC, respectively. In the SCLC group, a multivariate analysis showed that adjuvant chemotherapy (hazard ratio 0.54, 95% confidence interval 0.30-0.99, p = 0.04) was the only factor that was significantly associated with OS. In the LCNEC group, univariate analyses demonstrated that pathologic stage I (p = 0.01) was the only factor that was associated with better OS after surgery. CONCLUSIONS: We found different clinical features in SCLC and LCNEC; in patients with SCLC, because OS could be expected to significantly improve with postoperative adjuvant chemotherapy, patients with resected SCLC of any pathologic stage should receive adjuvant chemotherapy. For patients with LCNEC, because pathologic stage I LCNEC is related to better prognosis than any other stages, a thorough clinical staging, including invasive staging, according to present guidelines should be performed to identify clinical stage I LCNEC with the highest certainty.

Impact of 18F-FDG PET on TNM Staging and Prognosis in Thymic Epithelial Tumors.

BACKGROUND: Preoperative fluorine-18-fluorodeoxyglucose positron emission tomography (18F-FDG PET) of thymic epithelial tumors (TETs) is well known for identifying malignant-grade TETs; however, its predictive power for determining locally advanced tumors, lymph node (LN) metastasis, and prognosis remains unknown. PATIENTS AND METHODS: We retrospectively evaluated patients with resectable TETs who were preoperatively assessed using 18F-FDG PET from January 2012 to January 2023. The receiver operating characteristic curve was used to evaluate the cutoff value of the maximum standardized uptake value (SUVmax) to predict advanced-stage disease. Recurrence/progression-free survival (RFS/PFS) was analyzed using the Kaplan-Meier method. The staging was classified according to the tumor-node-metastasis system. RESULTS: Our study included 177 patients; 145 (81.9%) had pathological early-stage TET (stage I or II), and 32 (19.1%) had advanced stage (stage III or IV). The area under the curve value for predicting the advanced stage was 0.903, and the cutoff value was 5.6 (sensitivity 81.3%, specificity 84.8%). SUVmax > 5.6 was associated with worse prognosis for RFS/PFS. LN metastasis was preoperatively detected by FDG uptake in 30.8% of patients with pathological LN positivity, whereas LN metastasis was not pathologically detected in patients with SUVmax < 5.9. In patients with advanced-stage TETs, LN recurrence was more frequent in patients who were preoperatively detected by 18F-FDG PET than those who were not (75.0% versus 7.1%). CONCLUSIONS: 18F-FDG PET is a potentially valuable tool for predicting advanced stage and poor prognosis of recurrence in patients with TETs. SUVmax can help thoracic surgeons to guide them in selecting appropriate therapeutic strategies for TETs.

The Lung Cancer Surgical Study Group of the Japan Clinical Oncology Group: outstanding contribution and entering a new phase.

The Lung Cancer Surgical Study Group (LCSSG) of the Japan Clinical Oncology Group (JCOG) was organized in 1986 and initially included 26 collaborative institutions, which has increased to 52 institutions currently. JCOG-LCSSG includes thoracic surgeons, medical oncologists, pathologists, and radiotherapists. In the early period, the JCOG-LCSSG mainly focused on combined modality therapies for lung cancer. Since the 2000s, the JCOG-LCSSG has investigated adequate modes of surgical resection for small-sized and peripheral non-small cell lung cancer and based on the radiological findings of whole tumor size and ground-glass opacity. Trials, such as JCOG0802, JCOG0804, and JCOG1211, have shown the appropriateness of sublobar resection, which has significantly influenced routine clinical practice. With the introduction of targeted therapy and immunotherapy, treatment strategies for lung cancer have changed significantly. Additionally, with the increasing aging population and medical costs, tailored medicine is strongly recommended to address medical issues. To ensure comprehensive treatment, strategies, including surgical and nonsurgical approaches, should be developed. Currently, the JCOG-LCSSG has conducted numerous clinical trials to adjust the diversity of lung cancer treatment strategies. This review highlights recent advancements in the surgical field, current status, and future direction of the JCOG-LCSSG.

Updated review of perioperative treatment for non-small-cell lung cancer in the new era of immune checkpoint inhibitors: past, present, and future.

The perioperative treatments for non-small cell lung cancer (NSCLC) should control both local and microscopic systemic disease, because the survival of patients with NSCLC who underwent surgical resection alone has been dismal except in stage IA patients. One way to improve surgical outcome is the administration of chemotherapy before or after the surgical procedure. During the last two decades, many clinical studies have focused on developing optimal adjuvant or neoadjuvant cisplatin-based chemotherapy regimens that can be combined with surgical treatment and/or radiotherapy. Based on the results of those clinical studies, multimodality therapy has been considered to be an appropriate treatment approach for locally advanced NSCLC patients. When nodal involvement is discovered postoperatively, adjuvant cisplatin-based chemotherapy has conferred an overall survival benefit. More recently, neoadjuvant and/or adjuvant use of immunotherapy adding to the cisplatin-based chemotherapy has been revealed to improve survival of the patients with locally advanced NSCLC in many large-scale clinical trials; although, optimal treatment strategies are still evolving.

Oncological feasibility of segmentectomy for inner-located lung cancer.

Objective: Oncological feasibility of segmentectomy for internal non-small cell lung cancer (NSCLC) has not been assessed adequately. We assessed the oncological feasibility of segmentectomy for inner-located NSCLC by investigating surgical margins and patient prognosis after undergoing the procedure. Methods: Of the 3555 patients who underwent resection for lung cancer between 2013 and 2019 at our institution, 659 patients who underwent segmentectomy for clinical stage 0 to stage1A NSCLC were included in this study. Patients were separated into 2 groups according to whether the tumor was in the inner or outer third of the lung area. Clinical characteristics and prognoses were retrospectively compared between the groups. Results: Of the included 659 cases, 183 (27.8%) were inner-located, and 476 (72.2%) had outer-located NSCLC. The surgical margin was significantly shorter in the inner-located group than in the outer group (median, 16 vs 25 mm; P < .001). The 5-year recurrence-free survival and overall survival probabilities were 91.1%/91.8% (P = .530) and 94.1%/95.6% (P = .345) for inner/outer-located groups, respectively. Multivariate analysis showed that clinical stage IA2 or 3 (P = .043), lymphovascular invasion (P < .001), and surgical margins <20 mm (P = .017) were independent prognostic factors for recurrence-free survival. The location of the inner or outer tumors was not related to the prognosis. Conclusions: For clinical stage 0 to stage1A NSCLC, tumor location in the inner two-thirds of the lung was not associated with prognosis after segmentectomy. Because one of the independent prognostic factors is margin distance, segmentectomy for inner-located NSCLC would be oncologically acceptable when an adequate surgical margin is secured.

The International Association for the Study of Lung Cancer (IASLC) Staging Project for Lung Cancer: Recommendation to Introduce Spread Through Air Spaces as a Histologic Descriptor in the Ninth Edition of the TNM Classification of Lung Cancer. Analysis of 4061 Pathologic Stage I NSCLC.

INTRODUCTION: Spread through air spaces (STAS) consists of lung cancer tumor cells that are identified beyond the edge of the main tumor in the surrounding alveolar parenchyma. It has been reported by meta-analyses to be an independent prognostic factor in the major histologic types of lung cancer, but its role in lung cancer staging is not established. METHODS: To assess the clinical importance of STAS in lung cancer staging, we evaluated 4061 surgically resected pathologic stage I R0 NSCLC collected from around the world in the International Association for the Study of Lung Cancer database. We focused on whether STAS could be a useful additional histologic descriptor to supplement the existing ones of visceral pleural invasion (VPI) and lymphovascular invasion (LVI). RESULTS: STAS was found in 930 of 4061 of the pathologic stage I NSCLC (22.9%). Patients with tumors exhibiting STAS had a significantly worse recurrence-free and overall survival in both univariate and multivariable analyses involving cohorts consisting of all NSCLC, specific histologic types (adenocarcinoma and other NSCLC), and extent of resection (lobar and sublobar). Interestingly, STAS was independent of VPI in all of these analyses. CONCLUSIONS: These data support our recommendation to include STAS as a histologic descriptor for the Ninth Edition of the TNM Classification of Lung Cancer. Hopefully, gathering these data in the coming years will facilitate a thorough analysis to better understand the relative impact of STAS, LVI, and VPI on lung cancer staging for the Tenth Edition TNM Stage Classification.

Whole-genome sequencing reveals the molecular implications of the stepwise progression of lung adenocarcinoma.

The mechanism underlying the development of tumors, particularly at early stages, still remains mostly elusive. Here, we report whole-genome long and short read sequencing analysis of 76 lung cancers, focusing on very early-stage lung adenocarcinomas such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma. The obtained data is further integrated with bulk and spatial transcriptomic data and epigenomic data. These analyses reveal key events in lung carcinogenesis. Minimal somatic mutations in pivotal driver mutations and essential proliferative factors are the only detectable somatic mutations in the very early-stage of AIS. These initial events are followed by copy number changes and global DNA hypomethylation. Particularly, drastic changes are initiated at the later AIS stage, i.e., in Noguchi type B tumors, wherein cancer cells are exposed to the surrounding microenvironment. This study sheds light on the pathogenesis of lung adenocarcinoma from integrated pathological and molecular viewpoints.