Pulmonary Adenocarcinomas of Low Malignant Potential: Proposed Criteria to Expand the Spectrum Beyond Adenocarcinoma In Situ and Minimally Invasive Adenocarcinoma

Lung cancer screening has improved mortality among high-risk smokers but has coincidentally detected a fraction of nonprogressive adenocarcinoma historically classified as bronchoalveolar carcinoma (BAC). In the National Lung Screening Trial (NLST) the majority of BAC—comprising 29% of computed tomography–detected stage I lung adenocarcinoma—were considered overdiagnosis after extended follow-up comparison with the control arm. In the current classification, adenocarcinoma in situ and minimally invasive adenocarcinoma have replaced BAC but together comprise only ∼5% of stage I lung adenocarcinoma. Lepidic and subsets of papillary and acinar adenocarcinoma also infrequently recur. We, therefore, propose criteria for low malignant potential (LMP) adenocarcinoma among nonmucinous adenocarcinoma measuring ≤3 cm in total, exhibiting ≥15% lepidic growth, and lacking nonpredominant high-grade patterns (≥10% cribriform, ≥5% micropapillary, ≥5% solid),>1 mitosis per 2 mm2, angiolymphatic or visceral pleural invasion, spread through air spaces or necrosis. We tested these criteria in a multi-institutional cohort of 328 invasive stage I (eighth edition) and in situ adenocarcinomas and observed 16% LMP and 7% adenocarcinoma in situ/minimally invasive adenocarcinoma which together (23%) approximated the frequency of overdiagnosed stage I BAC in the NLST. The LMP group had 100% disease-specific survival. The proposed LMP criteria, incor...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research

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According to the 2015 World Health Organization (WHO) lung tumor classification [1], the predominant high-grade (solid and micropapillary) subtypes are commonly defined as tumors with unfavorable prognosis in patients with resected lung adenocarcinoma [2 –6]. In addition to morphological patterns typical of high-grade tumors, tumor spread through air spaces (STAS) is a newly recognized pattern of invasion in lung adenocarcinoma [1]. Kadota et al. provided the first evidence that STAS has prognostic value in lung carcinoma, as it is a significant p redictor of recurrence in patients with stage I small (≤2 cm...
Source: Lung Cancer - Category: Cancer & Oncology Authors: Source Type: research
AbstractPurposeThe study aimed to evaluate the clinicopathological and molecular profiles associated with programmed death ligand 1 (PD-L1) expression in non-small cell lung cell (NSCLC) in a large-scale, multi-center, real-world Chinese cohort.MethodsA total of 6295 NSCLC specimens from six centers in China were analyzed by PD-L1 (22C3) assay. PD-L1 expression in tumor cells (TCs) was classified as negative (TPS expression in  
Source: Journal of Cancer Research and Clinical Oncology - Category: Cancer & Oncology Source Type: research
CONCLUSION: The tumor doubling time of invasive lung adenocarcinoma differed according to the IASCL/ATS/ERS histologic classification. PMID: 33169551 [PubMed - as supplied by publisher]
Source: Korean Journal of Radiology - Category: Radiology Tags: Korean J Radiol Source Type: research
Conclusions: Our results suggest that invasive mediastinal staging should be probably encouraged in NSLCL male patients, with poorly differentiated adenocarcinoma lesions of the upper lobes. Considering the current lack of well-designed randomized trials, further studies are warranted in order to validate these findings, thus eliminating occult N2 involvement that may influence treatment decision-making and survival.
Source: European Respiratory Journal - Category: Respiratory Medicine Authors: Tags: Lung cancer Source Type: research
Immune checkpoint inhibitors against programmed cell death protein 1/programmed death-ligand 1 (PD-L1) have proven to be remarkably effective in non–small cell lung cancer. PD-L1 represents a predictive biomarker in lung cancer, although its heterogenous expression represents an emerging challenge for accurate biomarker-based patient selection. Lung adenocarcinomas (ADCs) show a high rate of intratumor morphologic heterogeneity that may reflect a heterogenous molecular and immunophenotypic profile. The aim of our study was to analyze the expression of PD-L1 in different intratumor subtypes and/or growth patterns in a...
Source: The American Journal of Surgical Pathology - Category: Pathology Tags: Original Articles Source Type: research
ConclusionThese data suggest that the mutational profiles among the predominant histological subtypes were very distinct, which provided a reliable tool to improve treatment decisions.
Source: Thoracic Cancer - Category: Cancer & Oncology Authors: Tags: ORIGINAL ARTICLE Source Type: research
Tumor spread through air spaces (STAS) as a new pathological invasion mode is closely related to many clinicopathological factors. In lung adenocarcinoma, micropapillary and solid pathological subtypes are most related; STAS for early stage lung adenocarcinoma, surgical type of lobectomy seems to benefit better than sublobar resection, which may up-regulate the pathological stage of early lung cancer; Moreover, STAS is closely related to squamous cell carcinoma and other non-small cell lung cancer (NSCLC). In addition, intraoperative frozen-section pathological detection of STAS is difficult and controversial. STAS as an i...
Source: Chinese Journal of Lung Cancer - Category: Cancer & Oncology Source Type: research
CONCLUSION: PD-L1-positive tumors were frequent in acinar predominant adenocarcinoma and solid predominant adenocarcinoma than other adenocarcinoma subtypes. PD-L1 expression seemed to increase according to pathologic tumor progression, suggesting a worse postoperative prognosis in NSCLC patients. PMID: 30282880 [PubMed - as supplied by publisher]
Source: Annals of Thoracic and Cardiovascular Surgery - Category: Cardiovascular & Thoracic Surgery Authors: Tags: Ann Thorac Cardiovasc Surg Source Type: research
Lung adenocarcinoma is characterized by a broad range of histologic patterns and driver or targetable mutations [1,2]. The tumor invasion patterns in lung adenocarcinoma are also diverse compared with other organ cancers [1,3]. Tumor cell proliferation along the preserved alveolar structure is defined as ‘lepidic pattern’ and regarded as ‘non-invasive’ or ‘in situ carcinoma’ [1,3]. In contrast, non-lepidic patterns, such as acinar, papillary, micropapillary, or solid, are defined as ‘invasive,’ as is tumor infiltration into the stroma with desmoplastic reaction, which is a co...
Source: Lung Cancer - Category: Cancer & Oncology Authors: Source Type: research
AbstractLung cancer is the commonest cause of death worldwide but unfortunately, most patients present in an advanced stage of the disease. The classification of lung cancer has evolved since the first WHO publication in 1981, and the present edition was published in March 2015. A major change in 2015 was the introduction of the new terms adenocarcinoma in situ and minimally invasive adenocarcinoma to describe early adenocarcinoma of lung and abolition of the previous term bronchioloalveolar carcinoma. Tumors with micropapillary pattern and those showing spread through alveolar spaces have significant clinical implications...
Source: Indian Journal of Thoracic and Cardiovascular Surgery - Category: Cardiovascular & Thoracic Surgery Source Type: research
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