Role of ground-glass opacity in pure invasive and lepidic component in pure solid lung adenocarcinoma for predicting aggressiveness

CT radiomics from intratumor and peritumor regions for predicting poorly differentiated invasive nonmucinous pulmonary adenocarcinoma

Per the 2021 World Health Organization (WHO) Classification of Thoracic Tumors, poorly differentiated invasive nonmucinous adenocarcinoma (INMA) demonstrates aggressive clinicopathological behavior characterized by lymphatic invasion, correlates with poor prognosis, and necessitates modifications to surgical planning even in early-stage adenocarcinoma. This study aimed to investigate the predictive value of radiomics features of intratumoral and peritumoral microenvironment in poorly differentiated INMA in the lung. A total of 451 patients with INMA were collected from three hospitals. They were divided into the train cohort (173 grade 1/2; 116 grade 3), internal test cohort (89 grade 1/2; 35 grade 3) and external test cohort (26 grade 1/2; 12 grade 3). The logistic regression analysis was used to establish the clinical and radiomic models. The receiver operating characteristic (ROC) curve and the decision curve analysis (DCA) were used to assess diagnostic performance of different models. The internal test dataset (124 patients) was used to evaluate the radiologists' performance without and with the assistance of optimal model. Nodule attenuation, consolidation size and consolidation-to-tumor ratio (CTR) meaning the ratio of maximum consolidation to tumor dimensions on axial imaging were independent predictors of poorly differentiated INMA (p < 0.05). In the internal test cohort, the area under the curve (AUC) values of the clinical model, the intratumor radiomic model, the combined 3 mm radiomic model, and the combined 5 mm radiomic model were 0.875(95%CI: 0.811-0.938), 0.882(95%CI: 0.807-0.957), 0.907(95%CI: 0.844-0.969) and 0.858(95%CI: 0.783-0.933), respectively. Corresponding results in the external test cohort showed moderate performance across all models: clinical model (AUC: 0.760, 95%CI: 0.603-0.916), intratumor radiomic model (AUC: 0.760, 95%CI: 0.580-0.939), and combined 3 mm/5 mm radiomic model(AUC: 0.772, 95%CI: 0.593-0.952; AUC: 0.766; 95%CIs: 0.580-0.953). Radiologists had higher diagnostic performance and confidence score with the aid of the combined 3 mm radiomic model. The combined 3 mm radiomic model of non-enhanced CT can identify poorly differentiated INMA with excellent performance and improve radiologists to achieve better diagnostic performance.

Reassessment of the Prognostic Implication of Ground-Glass Opacity: An Investigation Into Hypermetabolic Clinical Stage IA Lung Adenocarcinoma

BACKGROUND

Subsolid lung nodules represent a distinct group of lung cancers with less-aggressive biological behavior and favorable survival. We aimed to examine the prognostic impact of the ground-glass opacity (GGO) in clinical stage IA (cIA) lung adenocarcinoma with high metabolic activity.

METHODS

A retrospective study was conducted among patients with resected hypermetabolic and/or pure-solid cIA lung adenocarcinoma from a single institution database. The primary outcome was recurrence-free survival (RFS). The secondary outcomes included overall survival, pathological nodal upstaging, and recurrence rate.

RESULTS

A total of 621 patients were reviewed and classified into three groups: patients with low metabolic, solid nodules (SNs) into group A (N = 128), patients with hypermetabolic ground-glass nodules (GGNs) into group B (N = 105), and patients with hypermetabolic SNs into group C (N = 388). The five-year RFS of group B was significantly better than that of group C in the cT1a + T1b (93.3% vs. 72.5%, p = 0.002) subgroup but not in the cT1c (73.4% vs. 69.0%, p = 0.23) subgroup. Multivariable analysis showed that GGO component was an independent prognostic factor of RFS (hazard ratio [HR] = 0.41, 95% confidence interval [CI]: 0.19-0.89, p = 0.02) and protective factor of nodal upstaging (odds ratio [OR] = 0.44, 95% CI: 0.21-0.94, p = 0.03) among the hypermetabolic subgroup. All except one postoperative recurrence occurred in GGNs with solid component size > 2 cm.

CONCLUSIONS

The presence of GGO component was an independent prognostic factor even in hypermetabolic cIA lung adenocarcinoma. However, the oncologic outcomes of hypermetabolic GGNs were not equally favorable in different T categories.

Gene mutation, clinical characteristics and pathology in resectable lung adenocarcinoma

OBJECTIVE

With the wide use of CT scan in clinical practice, more lung cancer was diagnosed in resectable stage. Pathological examination and genetic testing have become a routine procedure for lung adenocarcinoma following radical resection. This study analyzed special pathological components and gene mutations to explore their relationship with clinical characteristics and overall survival.

METHODS

Clinical, pathological, and gene mutation data from 1,118 patients were collected. All patients underwent surgery at the Department of Thoracic Surgery, the Second Xiangya Hospital of Central South University. Patients were grouped based on pathological components and gene mutations. Differences in clinical features and overall survival were analyzed as well.

RESULTS

Patients with mucinous, neuroendocrine, and poor-differentiated components were presented with more prognostic risk factors, including pleural invasion, carcinothrombosis, STAS, and advanced stages, along with varying frequencies of gene mutations. These factors significantly shortened overall survival. ALK and KRAS mutations were also associated with risk factors such as solid nodules, pleural invasion, STAS, and later stages. However, a significant reduction in overall survival was observed only in patients with the KRAS mutation. Relationship between gene mutations and pathological components still requires further investigation.

CONCLUSION

Special pathological components (mucinous, neuroendocrine, and poor-differentiated) and gene mutations had an influence on biological behavior of tumors, resulting in different clinical characteristics and prognosis.

Sublobar Resection in Early Non-Small Cell Lung Cancer With Epidermal Growth Factor Receptor Mutant

BACKGROUND

Lobectomy is a standard surgical procedure for peripherally located early-stage non-small cell lung cancers (NSCLCs) measuring 2 to 4 cm. However, it is unclear whether sublobar resections, such as wedge resection and segmentectomy, are effective in treating tumors with driver mutations in the epidermal growth factor receptor (EGFR).

METHODS

We analyzed the clinicopathologic findings and surgical outcomes of 1395 patients with radiologically solid-dominant NSCLC measuring 2 to 4 cm, without clinical lymph node involvement, who underwent complete resection between 2010 and 2020. The patients, who underwent sublobar resections (n = 231) or lobectomy (n = 1164), were categorized by their EGFR mutation status and the surgical procedures performed. The follow-up was conducted for a median of 45.3 months.

RESULTS

The 5-year overall survival (OS) rates after sublobar resections (n = 39) were comparable to those after lobectomy (n = 359) in patients with EGFR mutation-positive tumors (80.5% [95% CI, 51.3%-93.2%] vs 88.8% [95% CI, 84.1%-92.1%], respectively; P = .16). Multivariable Cox regression analysis of OS revealed that the surgical procedure was an independent prognostic predictor in the entire cohort (hazard ratio, 0.6; 95% CI, 0.4-1.0; P = .028), but it was not an independent prognostic predictor in patients with EGFR-mutated tumors (hazard ratio, 0.6; 95% CI, 0.2-1.7; P = .32).

CONCLUSIONS

Sublobar resection with a secure surgical margin could be a viable option for appropriately selected patients with peripheral early-stage NSCLC tumors measuring 2 to 4 cm and harboring EGFR mutations, because it provides comparable OS to that of lobectomy.

Factors correlating the expression of PD-L1

OBJECTIVE

PD-L1 was an important biomarker in lung adenocarcinoma. The study was to confirm the most important factor affecting the expression of PD-L1 remains undetermined.

METHODS

The clinical records of 1045 lung adenocarcinoma patients were retrospectively reviewed. The High-Resolution Computed Tomography (HRCT) scanning images of all the participants were analyzed, and based on the CT characteristics, the adenocarcinomas were categorized according to CT textures. Furthermore, PD-L1 expression and Ki67 index were detected by immunohistochemistry. All patients underwent EGFR mutation detection.

RESULTS

Multivariate logistic regression analysis revealed that smoking (OR: 1.73, 95% CI: 1.04-2.89, p = 0.004), EGFR wild (OR: 1.52, 95% CI: 1.11-2.07, p = 0.009), micropapillary subtypes (OR: 2.05, 95% CI: 1.46-2.89, p < 0.0001), and high expression of Ki67 (OR: 2.02, 95% CI: 1.44-2.82, p < 0.0001) were independent factors which influence PD-L1 expression. In univariate analysis, tumor size > 3 cm and CT textures of pSD showed a correlation with high expression of PD-L1. Further analysis revealed that smoking, micropapillary subtype, and EGFR wild type were also associated with high Ki67 expression. Moreover, high Ki67 expression was observed more frequently in tumors of size > 3 cm than in tumors with ≤ 3 cm size as well as in CT texture of pSD than lesions with GGO components. In addition, multivariate logistic regression analysis revealed that only lesions with micropapillary components correlated with pSD (OR: 3.96, 95% CI: 2.52-5.37, p < 0.0001).

CONCLUSION

This study revealed that in lung adenocarcinoma high Ki67 expression significantly influenced PD-L1 expression, an important biomarker for immune checkpoint treatment.

Clinical Significance of the Proposed Pathologic Criteria for Invasion by the International Association for the Study of Lung Cancer in Resected Nonmucinous Lung Adenocarcinoma

INTRODUCTION

Accurate diagnostic criteria for tumor invasion are essential for precise pathologic tumor (pT) staging. Recently, the International Association for the Study of Lung Cancer (IASLC) Pathology Committee suggested a new set of criteria for assessing tumor invasion, but the clinical usefulness of the proposed criteria has not been evaluated.

METHODS

The study included 1295 patients with resected part-solid lung adenocarcinoma from January 2017 to December 2019 at the Samsung Medical Center, Seoul, Korea. The revised pT stage was determined by the extent of the newly measured invasive component using the IASLC criteria. The primary outcome was to compare the performance of the revised pT stage with the original pT stage in predicting recurrence-free survival and proof of invasion status (i.e., recurrence or lymph node metastasis). The secondary outcome was the correlation with radiologic surrogates of tumor invasiveness (consolidation-to-tumor ratio and maximum standardized uptake value) and pathologic risk factors.

RESULTS

The re-evaluation resulted in a 22% downstaging and 2.5% upstaging of pT, which improved the correlation with radiologic (consolidation-to-tumor ratio and maximum standardized uptake value) and pathologic risk factors. The revised pT staging allowed for more accurate discrimination of recurrence-free survival than the original pT staging (c-index = 0.794 versus 0.717). Moreover, the revised pT staging significantly improved the prediction of recurrence or lymph node metastasis (area under the curve = 0.818 versus 0.741, p < 0.001).

CONCLUSIONS

To our knowledge, this is the first study evaluating the clinical significance of the IASLC-proposed criteria for invasion. The proposed IASLC criteria offered better alignment with clinicopathologic risk factors and improved prognostication. Further studies are warranted to assess the impact of the IASLC criteria on treatment decisions and patient outcomes.

Synchrotron Radiation Refraction-Contrast Computed Tomography Based on X-ray Dark-Field Imaging Optics of Pulmonary Malignancy: Comparison with Pathologic Examination

Refraction-contrast computed tomography based on X-ray dark-field imaging (XDFI) using synchrotron radiation (SR) has shown superior resolution compared to conventional absorption-based methods and is often comparable to pathologic examination under light microscopy. This study aimed to investigate the potential of the XDFI technique for clinical application in lung cancer diagnosis. Two types of lung specimens, primary and secondary malignancies, were investigated using an XDFI optic system at beamline BL14B of the High-Energy Accelerator Research Organization Photon Factory, Tsukuba, Japan. Three-dimensional reconstruction and segmentation were performed on each specimen. Refraction-contrast computed tomographic images were compared with those obtained from pathological examinations. Pulmonary microstructures including arterioles, venules, bronchioles, alveolar sacs, and interalveolar septa were identified in SR images. Malignant lesions could be distinguished from the borders of normal structures. The lepidic pattern was defined as the invasive component of the same primary lung adenocarcinoma. The SR images of secondary lung adenocarcinomas of colorectal origin were distinct from those of primary lung adenocarcinomas. Refraction-contrast images based on XDFI optics of lung tissues correlated well with those of pathological examinations under light microscopy. This imaging method may have the potential for use in lung cancer diagnosis without tissue damage. Considerable equipment modifications are crucial before implementing them from the lab to the hospital in the near future.

Advances in diagnosis and prediction for aggression of pure solid T1 lung cancer

A growing number of early-stage lung cancers presenting as malignant pulmonary nodules have been diagnosed because of the increased adoption of low-dose spiral computed tomography. But pure solid T1 lung cancer with ≤3 cm in the greatest dimension is not always at an early stage, despite its small size. This type of cancer can be highly aggressive and is associated with pathological involvement, metastasis, postoperative relapse, and even death. However, it is easily misdiagnosed or delay diagnosed in clinics and thus poses a serious threat to human health. The percentage of nodal or extrathoracic metastases has been reported to be >20% in T1 lung cancer. As such, understanding and identifying the aggressive characteristics of pure solid T1 lung cancer is crucial for prevention, diagnosis, and therapeutic strategies, and beneficial to improving the prognosis. With the widespread of lung cancer screening, these highly invasive pure solid T1 lung cancer will become the main advanced lung cancer in future. However, there is limited information regarding precision medicine on how to identify these "early-stage" aggressive lung cancers. To provide clinicians with new insights into early recognition and intervention of the highly invasive pure solid T1 lung cancer, this review summarizes its clinical characteristics, imaging, pathology, gene alterations, immune microenvironment, multi-omics, and current techniques for diagnosis and prediction.