The Bronchioloalveolar Carcinoma and Peripheral Adenocarcinoma Spectrum of Diseases

Abstract

Bronchioloalveolar carcinoma (BAC) develops from terminal bronchiolar and acinar epithelia, growing along alveolar septa but without evidence of vascular or pleural involvement. A final diagnosis of BAC can only be achieved from a surgical specimen. Problematically, BAC may exhibit multifocal involvement by means of diffuse aerogenous metastatic spread, making this definition inapplicable for patients with stage IIIB to IV disease from whom only small size biopsy or cytological specimens are obtained. The recent interest and potential importance of BAC and the related peripheral adenocarcinoma (ADC), mixed subtype, is attributable to mounting evidence that some, perhaps many, of what are called peripheral ADCs have arisen from and often contain BAC. BAC, in turn, appears to arise from smaller peripheral nodules, called atypical adenomatous hyperplasia. These developments could account for part of the increase in ADCs noted in some countries, in particular, in East Asia. Interest also stems from the observation that advanced ADC, often with BAC features, are responding in surprising fashion to tyrosine kinase inhibitors. Furthermore, some of the more rapid, dramatic, and durable responses occur when specific mutations in the epidermal growth factor receptor are present. Clinical characteristics often differ from other types of non-small cell lung cancers. These include frequent female occurrence, especially in East Asians; no or less smoking history; an often indolent course; distinctive chest computed tomographic findings; frequent presentation as an asymptomatic, sometimes small, peripheral nodule(s)/mass; multifocal/synchronous primary tumors; and less frequently as pneumonic-type consolidation or diffuse, inoperable lesions, the latter two often with bronchorrhea, and with chest-only disease. Relapses also are predominantly pulmonary, perhaps related to aerogenous spread, and responsible for mortality. Lobectomy is the treatment of choice for cure, even with pneumonic consolidation, but lesser procedures such as wedge resection or segmentectomy may be considered for what might be multifocal, synchronous primary tumors and for pulmonary relapses. Because of frequent lung-only recurrences, lung transplantation, although performed rarely, may hold promise.

RhoB Determines Tumor Aggressiveness in a Murine EGFRL858R-Induced Adenocarcinoma Model and Is a Potential Prognostic Biomarker for Lepidic Lung Cancer

“…This subtype of carcinoma is associated with good survival when it is diagnosed at an early stage, but it can rapidly become invasive, spreading along the bronchial tree, invading through the basal membrane, and eventually leading to a very aggressive phenotype with a poor outcome (38)(39)(40)(41). The crucial event in the progression of this type of cancer is the switch from a "horizontal" spread toward "vertical" invasion of the basal membrane.…”

Prognostic role of clusterin in resected adenocarcinomas of the lung

“…We found BAC in only four patients (4.8%). However, up to 20% of invasive adenocarcinomas of the lung showed a mixed pattern, ranging from predominant BAC with a small focus of invasion, to invasive adenocarcinoma with an isolated group of cells with BAC features [18,26]. In our series, mixed adenocarcinomas with a BAC component accounted for 16% of all adenocarcinomas.…”

“…In addition, this is the only histologic type of lung cancer whose incidence is increasing, according to epidemiological studies [18]. Moreover, our series included a select group of patients who were racially homogeneous, being all caucasian, because of the different characteristics of adenocarcinomas [19].…”

Bronchioloalveolar Carcinoma and Minimally Invasive Adenocarcinoma

“…However, if the tumor is present with a pneumonic pattern radiographically or as a multifocal adenocarcinoma, the prognosis is different, and these tumors do not share the same 100% survival of the isolated nodular form. 7,29,30 The pneumonic form, although rare, is more commonly seen in mucinous BAC. This concept, however, is troublesome because in most series, only a few studies report a central review mechanism for the histology of the tumor included in the study.…”