Non-mucinous and mucinous subtypes of adenocarcinoma with bronchioloalveolar carcinoma features differ by biomarker expression and in the response to gefitinib

Impact of proposed IASLC/ATS/ERS classification of lung adenocarcinoma: prognostic subgroups and implications for further revision of staging based on analysis of 514 stage I cases

“…8 Worse survival for tumors formerly classified as mucinous BAC compared with those formerly classified as nonmucinous BAC has been suggested. 18,[34][35][36] However, the data are limited, other studies have not shown a significant survival difference, 37 and the histological criteria have evolved over time. 26 The latter problem complicates interpretation of the literature on this topic.…”

“…8 In this new classification (Table 1) there are several major changes for surgically resected tumors: (1) the term bronchioloalveolar carcinoma (BAC) is no longer used and the growth pattern of BAC is referred to as lepidic pattern; (2) adenocarcinoma in situ is proposed for small (r3 cm) solitary adenocarcinomas with pure lepidic growth lacking invasion; (3) minimally invasive adenocarcinoma (MIA) is proposed for small (r3 cm) lepidic predominant tumors with r0.5 cm of invasion; (4) invasive adenocarcinomas are now classified according to the predominant subtype after performing comprehensive histological subtyping with semiquantitative assessment of each subtype in 5% increments; 4 (5) micropapillary adenocarcinoma is added as a major subtype because of its poor prognostic significance in multiple studies of early stage lung adenocarcinoma; [9][10][11] (6) former mucinous BACs are now classified as invasive mucinous adenocarcinomas recognizing that most of these tumors will have invasive components, less expression of TTF-1, frequent KRAS mutations, characteristic CT finding primarily of consolidation rather than ground glass opacities, worse prognosis than non-mucinous lepidic predominant adenocarcinomas and lack of responsiveness to tyrosine kinase inhibitors; [12][13][14][15][16][17][18][19] and (7) clear cell and signet ring adenocarcinoma are recognized to represent cytological changes that occur in multiple histological subtypes rather than in separate histological subtype. 20,21 We sought to explore the prognostic significance of this classification in a large series of surgically resected stage I lung adenocarcinomas.…”

Nkx2-1: a novel tumor biomarker of lung cancer

“…Wislez et al (2010) studied bronchioloalveolar carcinoma (BAC) patients and found that 95% of non-mucinous tumors expressed Nkx2-1, compared to only 27% of mucinous tumors. Moreover, the non-mucinous tumors appeared to be more sensitive to EGFR-TKIs.…”

Bronchioloalveolar Carcinoma and Minimally Invasive Adenocarcinoma

“…7 The clinical presentation of a pure pneumonic nonmucinous BAC may be very rare and therefore it is difficult to conduct specific clinical trials; however, the clinical reports of pneumonic adenocarcinomas show that these nonmucinous BAC have a better prognosis compared with that of mucinous BAC when treated with gefitinib, a tyrosine kinase inhibitor. 7,31 Patients who present with synchronous multifocal GGO lung nodules pose a significant dilemma for diagnosis, staging, and treatment, because there are no established guidelines for the clinical management of these patients. Recent studies have showed that synchronous BAC can have a different EGFR mutational profile, thus suggesting that they more likely represent separate synchronous primaries than intrapulmonary Fig.…”