Bronchioloalveolar Carcinoma Subtype Research Articles

Novel PD-L1 mAb HC16 reveals upregulation of PD-L1 in BAC subtype.

Programmed death-ligand 1 (PD-L1) is an inhibitory transmembrane protein that can prevent autoimmune response. Upregulated PD-L1 serves as a predictive biomarker for patients who may respond well to immune checkpoint therapies. However, variable associations of PD-L1 level with prognoses have been reported. In this study, a short peptide sequence corresponding to PD-L1 amino acids 172-187 (from the extracellular Ig-like C-type domain, and with high predicted antigenicity and hydrophilicity) was used to generate a monoclonal antibody (mAb). The resultant PD-L1 mAb, clone HC16, was examined for binding specificity and reactivity in cancer cell-lines, as assessed by immunocytochemical, immunoblotting, and co-immunoprecipitation. The potential diagnostic and clinical applicability of clone HC16 was further tested using malignant tissue arrays derived from various cancer types analyzed with an automated immunohistochemical (IHC) staining platform. Additionally, tumor samples from patients diagnosed with non-small cell lung cancer (NSCLC) were analyzed by western blotting. Clone HC16 showed obvious staining activity in lung and breast cancer tissues. Interestingly, we observed that PD-L1 level was negatively associated with clinical stage in NSCLC. Strong PD-L1 expression tended to be found in patients diagnosed with bronchioloalveolar carcinoma (BAC). These results demonstrate that clone HC16 harbors good target specificity and is suitable for further development in diagnostic tools to assess PD-L1 expression in human tissues. In addition, our findings also suggest a role for PD-L1 in a non-invasive subtype of lung cancer.

Southwestern Oncology Group Phase II Trial (S0526) of Pemetrexed in Bronchioloalveolar Carcinoma Subtypes of Advanced Adenocarcinoma

BackgroundPemetrexed, a multitargeted antifolate drug, is an active agent in non–small-cell lung cancer (NSCLC), especially adenocarcinomas. Based on preclinical data supporting the relevance of alpha-folate receptors in adenocarcinoma of the bronchioloalveolar carcinoma (BAC) subtype, this trial was designed to assess pemetrexed in patients with this pathologic subtype of lung adenocarcinoma. Patients and MethodsPatients with histologically confirmed stage IIIB (with malignant pleural effusion) or stage IV adenocarcinoma with BAC features or pure BAC were eligible. Treatment consisted of pemetrexed, 500 mg/m2, administered intravenously every 21 days. ResultsOf 27 patients enrolled, 24 were eligible and assessable for adverse events: Toxicity was primarily hematologic, consisting of leukopenia/neutropenia, thrombocytopenia, and anemia. The median follow-up among patients still alive (n = 8) was 35 months (range, 26-47 months). Among 17 patients with measurable disease, the response rate was 23% (all partial responses; 95% confidence interval [CI], 10%-56%). The median progression-free survival (PFS) and overall survival (OS) were 6 and 25 months, respectively. ConclusionPemetrexed is active and well tolerated and, in patients with adenocarcinoma BAC subtypes, likely related to its underlying mechanism of action as a multitargeted antifolate drug.

Stereotactic body radiation therapy for the treatment of early-stage minimally invasive adenocarcinoma or adenocarcnioma in situ (formerly bronchioloalveolar carcinoma): a patterns of failure analysis

IntroductionOngoing prospective trials exploring stereotactic body radiation therapy (SBRT) for early stage non-small cell lung cancer (NSCLC) often exclude minimally invasive adenocarcinoma or adenocarcnioma in situ, formerly bronchioloalveolar carcinoma (BAC), due to concerns for accurate target delineation on CT. We performed a patterns of failure analysis to compare outcomes between BAC and other NSCLC subtypes.MethodsOne hundred twenty patients with early stage NSCLC were treated with SBRT from 2004–2009. Pathologic confirmation of NSCLC was obtained in 97 patients. Radiotherapy was delivered according to RTOG guidelines. The log-rank test was used to compare outcomes between BAC and other NSCLC.ResultsMedian follow-up was 29 months. The median SBRT dose was 5400 cGy. Thirteen patients had radiographically diagnosed BAC and five patients had biopsy confirmed BAC, of which two had both. The three-year local control was 100% for biopsy-proven or radiographically diagnosed BAC (n = 18) and 86% for all other NSCLC subtypes (n = 102) (p = 0.13). Likewise, no significant difference was detected between BAC and other NSCLC for 3-year regional failure (12% vs. 20%, p = 0.45), progression-free survival (57.6% vs. 53.5%, p = 0.84) or overall survival (35% vs. 47%, p = 0.66). There was a trend towards lower three-year rates of freedom from distant failure in patients with any diagnosis of BAC compared to those without (26% vs. 38%, p = 0.053).ConclusionsCompared to other NSCLC subtypes, BAC appears to have similar patterns of failure and survival after treatment with SBRT, however there may be an increased risk of distant metastases with BAC. RTOG guideline-based target delineation provides encouraging local control rates for patients with BAC.

Abstract A10: Prognostic significance of CXCL10/CXCR3 overexpression in mucinous bronchioloalveolar carcinoma

Abstract Introduction: The 2004 WHO Pathological classification distinguishes two cytological subtypes of bronchioloalveolar carcinoma (BAC): mucinous (M) and non-mucinous (NM). This distinction appears to be relevant in terms of clinical characteristics, prognostic and treatment effectiveness. We attempted to better characterize the molecular profile of M relative to NM. Experimental procedures: Bronchoalveolar lavage fluid (BALF) supernatants from M-BACs (n = 23) and NM-BACs (n = 11) were analyzed for 30 cytokines (IL-1β, IL-1ra, IL-2, IL-4, IL-5, IL-6, IL-7, IL-9, IL-10, IL-12, IL-13, IL-15, IL-17, FGF, PDGF, HGF, VEGF, Eotaxin, G-CSF, GM-CSF, IFNγ, CXCL-1, CXCL-8, CXCL-10, MCP-1, MIP-1α, MIP-1β, TNF-α, RANTES, VCAM-1) by Bio-Plex multiplex bead-based assay (BIORAD, Marne la Coquette, France). Cytokines of interest expression was studied on paraffin embedded specimens from surgical specimens (n = 45) using immunochemistry. EGFR and K-ras mutation analysis using direct PCR and Alk overexpression detection using immunochemistry were also performed. Univariate and multivariate analysis by Cox model was undertaken to identify the variables associated with a risk for shortened survival. Summary of results: Among the 30 chemokines analyzed, CXCL10 was the only one for which concentration was significantly higher in BALF supernatants from M-BAC (n = 23) compared to NM-BAC (n = 11) and control (n = 4) (p = 0.041). The cellular source of CXCL10 was not yet identified while CXCR3, its receptor, was expressed by tumor cells. CXCR3 was more frequently and more intensively expressed in M-BAC (n = 21) than in NM-BAC (n = 24) (52% vs 17%, p=0.023 and 52±16 vs 12±6, p = 0.047, respectively). EGFR mutation was never found in M-BAC (0%, 0/21) while present in 21% (5/24) of NM-BAC (p = 0.026). K-ras mutation and Alk overexpression did not differ between the two subtypes (2/21 vs 1/24, p > 0,05 and 3/21 vs 2/24, p > 0,05, respectively). The expression of CXCR3 was not associated with EGFR or K-ras mutation or Alk overexpression. In univariate analysis, factors associated with shorter survival were CXCL10 BALF concentration (HR=2.615, 95% CI: 1.102–6.206), PS > 0 (HR=1.308, 95% CI: 1.131–1.726) and bilateral extension (HR=2.914, 95% CI: 1.208–7.031). Multivariate analysis did not show any independent prognostic factor. Conclusions: Our results show a CXCL10/CXCR3 overexpression in M-BAC compared to NM-BAC and suggest an association between CXCL10 overexpression and shorter survival.

Prognostic Impact of Histology on Early-Stage Non-small Cell Lung Cancer

The purpose of this study is to evaluate the significance of histology as a predictor of recurrence after resection in patients with early-stage non-small cell lung cancer. A total of 1,870 consecutive patients in stage I and II with adenocarcinoma or squamous cell carcinoma (SCC) who underwent complete tumor resection with systematic lymph node dissection between August 1992 and December 2007 were included. In patients with SCC, significantly more tumors were stage IB or higher. Ever smokers were more common in patients with SCC, and more patients with SCC died of other diseases. In stage IA, a statistically significant difference in the 5-year recurrence-free probability was observed between adenocarcinoma and SCC (91.4% and 82.6%, respectively; P < .001), whereas no such difference was observed in stage IB (74.4% and 73.6%, respectively; P = .934). In stage II, the 5-year recurrence-free probability for adenocarcinoma was significantly lower than that for SCC (47% and 73%, respectively; P < .001). In stage IA, patients with predominantly bronchioloalveolar carcinoma subtype were more common compared with stage IB or higher in patients with adenocarcinoma. It is important to offset the prognostic impact of comorbidities associated with cigarette smoking because more patients with SCC died of other diseases. When evaluating its significance as a predictor of recurrence stratified by stage, histology showed a different impact on postoperative recurrence within different substages. Histologic subtype distribution was different among substages in patients with adenocarcinoma. Disease stages should be considered while evaluating histology as a predictor of recurrence.

IFCT-0504 trial: Mucinous (M) and nonmucinous (NM) cytologic subtypes interaction effect in first-line treatment of advanced bronchioloalveolar carcinoma (BAC) by erlotinib (E) or carboplatin/paclitaxel (C/P).

7521 Background: First-line EGFR-TKI in advanced BAC yielded a 2.9 to 4-month PFS in Phase II trials. We have suggested that EGFR-TKI had a reduced activity in M-BAC but that C/P and pemetrexed could have some effect, in both cytological BAC subtypes. To determine the best therapeutic strategy for advanced BAC, we conducted a multicentric randomized phase II trial to evaluate in first-line treatment E (150 mg/d) or C/P (AUC 6 d1 / 90mg/m² d1,8,15 four-weekly) with a cross-over at progression and pemetrexed in third-line. Methods: Inclusion criteria: previously untreated, cyto/pathologically proven advanced BAC. Primary objective: 4-month disease control rate (DCR) >30% and PFS >3.0 months. Secondary objectives: tolerance, QOL, OS and subgroups analyses by arms, cytological subtypes and predefined biomarkers. Results: From 09/06 to 07/09, 130/133 patients were eligible: median age (68 yrs), PS <2 (87%), females (39%), never smokers (27%), stage IIIB-IV (91%), NM (46%), M (41%) and undetermined (13%) BAC. DCR was 46% (37-55), PFS=3.5 months (2.6-5.6) and OS=19.5 months (12.1-28.7). Grade ≥3 toxicity (>5%): skin for E and hematological/febrile neutropenia and neuropathy for C/P; 1 death-related toxicity with E. DCR and PFS were independently associated with smoking (p=0.008 and p=0.02), respiratory symptoms score (p=0.01 and p=0.004). DCR was also associated with age >70 yrs (p=0.03) and PFS with treatment arms (p=0.03). Although PFS improved with C/P compared to E (HR=0.667 [0.461-0.966], p=0.03), OS did not differ between the two arms (21.0 [15-33] and 16.4 [12-29] for E and C/P, respectively). Finally, an independent interaction (p=0.035) was observed for the PFS, between treatment arms and cytological subtypes. Increased risk of progression was observed with E compared to C/P for M-BAC (HR=2.7 [1.4-5.1], p=0.003), but not for NM-BAC (HR=0.90 [0.51-1.54]). Conclusions: IFCT-0504 trial showed that: 1) C/P is effective in both M- and NM-BAC; and 2) E is as effective as C/P in NM-BAC, but less in M-BAC. Finally, it suggested that strategy including C/P and E contributed to improve survival in advanced BAC.

International association for the study of lung cancer/american thoracic society/european respiratory society international multidisciplinary classification of lung adenocarcinoma.

Adenocarcinoma is the most common histologic type of lung cancer. To address advances in oncology, molecular biology, pathology, radiology, and surgery of lung adenocarcinoma, an international multidisciplinary classification was sponsored by the International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society. This new adenocarcinoma classification is needed to provide uniform terminology and diagnostic criteria, especially for bronchioloalveolar carcinoma (BAC), the overall approach to small nonresection cancer specimens, and for multidisciplinary strategic management of tissue for molecular and immunohistochemical studies. An international core panel of experts representing all three societies was formed with oncologists/pulmonologists, pathologists, radiologists, molecular biologists, and thoracic surgeons. A systematic review was performed under the guidance of the American Thoracic Society Documents Development and Implementation Committee. The search strategy identified 11,368 citations of which 312 articles met specified eligibility criteria and were retrieved for full text review. A series of meetings were held to discuss the development of the new classification, to develop the recommendations, and to write the current document. Recommendations for key questions were graded by strength and quality of the evidence according to the Grades of Recommendation, Assessment, Development, and Evaluation approach. The classification addresses both resection specimens, and small biopsies and cytology. The terms BAC and mixed subtype adenocarcinoma are no longer used. For resection specimens, new concepts are introduced such as adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) for small solitary adenocarcinomas with either pure lepidic growth (AIS) or predominant lepidic growth with ≤ 5 mm invasion (MIA) to define patients who, if they undergo complete resection, will have 100% or near 100% disease-specific survival, respectively. AIS and MIA are usually nonmucinous but rarely may be mucinous. Invasive adenocarcinomas are classified by predominant pattern after using comprehensive histologic subtyping with lepidic (formerly most mixed subtype tumors with nonmucinous BAC), acinar, papillary, and solid patterns; micropapillary is added as a new histologic subtype. Variants include invasive mucinous adenocarcinoma (formerly mucinous BAC), colloid, fetal, and enteric adenocarcinoma. This classification provides guidance for small biopsies and cytology specimens, as approximately 70% of lung cancers are diagnosed in such samples. Non-small cell lung carcinomas (NSCLCs), in patients with advanced-stage disease, are to be classified into more specific types such as adenocarcinoma or squamous cell carcinoma, whenever possible for several reasons: (1) adenocarcinoma or NSCLC not otherwise specified should be tested for epidermal growth factor receptor (EGFR) mutations as the presence of these mutations is predictive of responsiveness to EGFR tyrosine kinase inhibitors, (2) adenocarcinoma histology is a strong predictor for improved outcome with pemetrexed therapy compared with squamous cell carcinoma, and (3) potential life-threatening hemorrhage may occur in patients with squamous cell carcinoma who receive bevacizumab. If the tumor cannot be classified based on light microscopy alone, special studies such as immunohistochemistry and/or mucin stains should be applied to classify the tumor further. Use of the term NSCLC not otherwise specified should be minimized. This new classification strategy is based on a multidisciplinary approach to diagnosis of lung adenocarcinoma that incorporates clinical, molecular, radiologic, and surgical issues, but it is primarily based on histology. This classification is intended to support clinical practice, and research investigation and clinical trials. As EGFR mutation is a validated predictive marker for response and progression-free survival with EGFR tyrosine kinase inhibitors in advanced lung adenocarcinoma, we recommend that patients with advanced adenocarcinomas be tested for EGFR mutation. This has implications for strategic management of tissue, particularly for small biopsies and cytology samples, to maximize high-quality tissue available for molecular studies. Potential impact for tumor, node, and metastasis staging include adjustment of the size T factor according to only the invasive component (1) pathologically in invasive tumors with lepidic areas or (2) radiologically by measuring the solid component of part-solid nodules.

Histopathologic Features of the Tumor Budding in Adenocarcinoma of the Lung: Tumor Budding As an Index to Predict the Potential Aggressiveness

The term tumor budding has been applied to single cells or small clusters of up to four cells within the stromal tissue at the invasive margin of colorectal cancers. This morphologic feature is increasingly being recognized as an adverse prognostic factor. The purpose of this study was to evaluate the clinicopathologic significance of tumor budding in adenocarcinomas of the lung. We investigated the relationship between tumor budding and clinicopathologic parameters of adenocarcinomas of the lung and the prognostic significance of tumor budding by reviewing the cases of 201 consecutive patients who had undergone complete resection of adenocarcinoma of the lung measuring 30 mm or less in diameter. We examined immunohistochemical profile of budding cells (BCs) by immunohistochemical staining with 14 antibodies. Tumor budding was observed in 78 (43.1%) of the 181 cases with invasive adenocarcinoma. The presence of tumor budding was significantly associated with lymph node metastasis (p = 0.005), pathologic stage (p < 0.001), vascular invasion (p = 0.003), lymphatic invasion (p = 0.009), and pleural invasion (p = 0.029). Examination of the relation between the presence of tumor budding and the predominant histologic subtype revealed that the predominant papillary subtype was significantly associated with the presence of tumor budding (p = 0.0023), whereas the predominant bronchioloalveolar carcinoma subtype was significantly associated with the absence of tumor budding (p < 0.001). The overall 5-year survival rates of the group with budding and the group without budding was 67.5% and 88.3%, respectively, and difference was significant (p = 0.0057). Compared with cancer cells forming nests, BCs displayed reduced expression of cellular adhesion molecule, E-cadherin, and beta-catenin (p < 0.05 and p < 0.05, respectively) and increased expression of laminin5-gamma2 (p < 0.05). However, BCs displayed reduced expression of differentiation marker, surfactant protein A (p < 0.05). Multivariate analysis revealed that tumor budding was significant independent prognostic factor of the small-sized adenocarcinoma of the lung. Our data showed that tumor budding in adenocarcinoma of the lung is a distinct morphologic feature that has biologic and prognostic significance.

IFCT-0401 Trial: A Phase II Study of Gefitinib Administered as First-Line Treatment in Advanced Adenocarcinoma with Bronchioloalveolar Carcinoma Subtype

Intergroupe Francophone de Cancérologie Thoracique-0401 phase II trial aimed to evaluate the efficacy and safety of gefitinib as a first-line treatment for patients with adenocarcinoma with bronchioloalveolar carcinoma subtype (ADC-BAC). Chemotherapy-naive patients (n = 88) with advanced ADC-BAC were treated with 250 mg/d of gefitinib. The primary objective was assessment of disease control rate (DCR [objective response + stable disease]) at 3 months using World Health Organization criteria. A disease control rate of 25% or greater would be of interest in this patient population. Progression-free survival (PFS), overall survival (OS), and toxicity were the secondary criteria. Clinical and disease characteristics that conferred a favorable prognosis under gefitinib were also analyzed. Disease control was achieved in 25 patients (29.4%); 11 patients (12.9%) had partial response and 14 (16.4%) had stable disease. Median PFS was 2.9 months (95% confidence interval [CI], 2.3-3.2) and median OS was 13.2 months (95% CI, 10.2-17.3). Never smokers, patients with low respiratory symptoms score, occurrence of cutaneous rash, and nonmucinous ADC-BAC subtype were associated with increased probability of disease control. Nonmucinous ADC-BAC was associated with increased PFS and OS at 3 years. Patients with nonmucinous BAC had longer OS and PFS compared with patients with other ADC-BAC variants; median PFS for nonmucinous BAC was 11.3 months (95% CI, 3.2-14.7), whereas it was 2.6 months (95% CI, 2.1-3) for mucinous BAC. As expected, toxicity was low, with dermatological problems, diarrhea, and nausea being the most common adverse events. Results from the Intergroupe Francophone de Cancérologie Thoracique-0401 trial demonstrate that gefitinib combines efficacy with low toxicity and is, therefore, suitable as a first-line treatment of advanced ADC-BAC, particularly in patients with nonmucinous BAC subtype.

The Study on Gene Amplification of EGFR in Bronchioloalveolar Carcinoma and Conventional Adenocarcinoma of the Lung.

Patients with adenocarcinoma of the lung have disproportionately response to the epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI). The aim of this study is to analyze the difference of EGFR gene amplification in bronchioloalveolar carcinoma (BAC), adenocarcinma mixed subtype and conventional adenocarcinoma of the lung and provide some information to clinical therapies. Lung cancer cases were collected and reviewed from the archives of the Department of Pathology, Chinese PLA General Hospital during the time period from 2004 to 2006. The definite diagnosis of BAC based on 2004 WHO classification of lung tumors was made by two pathologists. Fluorescence in situ hybridization (FISH) was performed to detect EGFR gene amplification in pure BAC, adenocarcinma mixed subtype and conventional adenocarcinoma. Conventional adenocarcinoma had higher EGFR amplification compared with pure BAC and adenocarcinma mixed subtype (Chi-square=11.632, P<0.05). EGFR gene amplification was found in 45.45% of conventional adenocarcinoma, 14.81% in pure BACs, and 22.58% in adenocarcinma mixed subtype. EGFR gene amplification was observed as scattered signals in most cases. EGFR gene amplification was seen more frequently in the invasive components than in BAC. EGFR gene amplification might be associated with the development of adenocarcinoma of the lung.

The Importance of Distinguishing Mucinous and Nonmucinous Bronchioloalveolar Carcinomas

It was with some surprise and dismay that we noted the recent paper in your journal, ‘‘Expression of FAK and PTEN in bronchioloalveolar carcinoma and lung adenocarcinoma,’’ [1] did not distinguish between the two subtypes of bronchioloalveolar carcinoma (BAC) nodules— mucinous (M) and nonmucinous (NM)—which are welldescribed in the most recent 2004 lung cancer classification [2]. The more frequent BAC is NM, reported in up to 50% of cases. M is reported in 25–50% [2–4], although these percentages may not be the same in patients from East Asia. Rarely there is a combination of both. Now there is increasing evidence that M and NM represent two separate disease entities [3–8], so it is important to distinguish them, especially in resected cases. Although it is difficult, if not impossible, to distinguish the two preoperatively, CT findings may be suggestive. Of the 77 BAC cases described in your study, 27 (35%) demonstrated an air bronchogram, seen more often in M in the most recent study [9]. Also, what is described in the study as ‘‘cavitation,’’ rare in BAC, perhaps is the same as ‘‘pseudocavitation,’’ although only noted in 6 of 77 (8%), is seen more often in M nodules (\3.0 cm; P 0.01) [9]. Therefore, as many as 33 of 77 (43%) BAC nodules could have been M-BAC in this study. Because NM-BAC seems driven more by the epidermal growth factor receptor (EGFR) pathway, whereas M-BAC is driven by mutations of K-ras, a potent oncogene [7], it might be informative to determine where PTEN (phosphate and tensin homolog), a tumor-suppressor gene regulating apoptosis, and FAK (focal adhesion molecule), a cell migration and differentiation molecule, are involved in M and NM in these 77 resected BAC cases. In fact, such results may be more robust. Clearly, much more needs to be known about these two apparently separate entities.

The Impact of Cigarette Smoking on Prognosis in Small Adenocarcinomas of the Lung: The Association Between Histologic Subtype and Smoking Status

In this retrospective study, we clarified the impact of smoking on prognosis and the association of clinicopathological factors, particularly histologic subtype, in patients with small adenocarcinoma of the lung. Between 1996 and December 2006, 121 patients presenting with adenocarcinomas that had a diameter </=2 cm were analyzed. The clinicopathological records of the patients were examined for age, gender, nodal status (c-N and p-N), tumor size, serum carcinoembryonic antigen level, histologic subtype, and smoking history. A histologic subtype was defined using a modified World Health Organization classification. These subtypes are bronchioloalveolar carcinoma (BAC), adenocarcinoma with little or no BAC component (Non or min BAC), and mixed bronchioloalveolar carcinoma with other adenocarcinoma components. The overall 5-year survival rates were 94.4% for never-smokers (N = 55) and 79.2% for smokers (N = 66) (p = 0.05). Cancer-specific 5-year survival rates were 98.0% for never-smokers and 80.4% for smokers (p = 0.03). Gender, serum carcinoembryonic antigen level, and histologic subtype were significantly associated with smoking status. Histologic subtype (Non or min BAC) was the only significant prognostic factor in multivariate analyses. The prevalence of smoking by histologic subtype was 27.3% for BAC, 43.2% for mixed bronchioloalveolar carcinoma, and 74.6% for Non or min BAC. The prevalence was significantly higher in Non or min BAC than in the others. Furthermore, the smoking index (daily cigarette consumption times years of smoking) was significantly higher in Non or min BAC than in the other two subtypes. In addition, patients with a high smoking index showed a greater percentage of Non or min BAC subtypes. Finally, male gender was associated with Non or min BAC independent of smoking status (p = 0.03). When adenocarcinomas were small (diameter </=2 cm) cigarette smoking and male gender were associated with Non or min BAC histologic subtypes, which are thought to have more aggressive biologic features resulting in poorer outcome compared with other subtypes.

Molecular Characteristics of Bronchioloalveolar Carcinoma and Adenocarcinoma, Bronchioloalveolar Carcinoma Subtype, Predict Response to Erlotinib

We conducted this phase II trial to determine the efficacy of erlotinib in patients with bronchioloalveolar carcinoma (BAC) and adenocarcinoma, BAC subtype, and to determine molecular characteristics associated with response. Patients (n = 101) with BAC (n = 12) or adenocarcinoma, BAC subtype (n = 89), were enrolled. All patients received erlotinib 150 mg daily. Epidermal growth factor receptor (EGFR) mutation, EGFR copy number, EGFR immunohistochemistry (IHC), and KRAS mutation status were analyzed in available tumors. The primary end point was response rate (RR). Overall RR was 22% (95% CI, 14% to 31%). In patients with pure BAC, the RR and median survival were 20% and 4 months, as compared with 23% and 19 months in those with adenocarcinoma, BAC subtype. No patient (zero of 18; 95% CI, 0% to 19%) whose tumor harbored a KRAS mutation responded to erlotinib. Patients with EGFR mutations had an 83% RR (15 of 18; 95% CI, 65% to 94%) and 23-month median OS. On univariate analysis, EGFR mutation and copy number were associated with RR and PFS. EGFR IHC was not associated with RR or progression-free survival (PFS). After multivariate analysis, only EGFR mutation was associated with RR and PFS. No molecular factors were associated with overall survival. Erlotinib is active in BAC and adenocarcinoma, mixed subtype, BAC. Testing for EGFR and KRAS mutations can predict RR and PFS after treatment with erlotinib in this histologically enriched subset of patients with non-small-cell lung cancer (NSCLC). These data suggest that histologic subtype and molecular characteristics should be reported in clinical trials in NSCLC using EGFR-directed therapy.

Increased Epidermal Growth Factor Receptor Gene Copy Number Detected by Fluorescence In Situ Hybridization Associates With Increased Sensitivity to Gefitinib in Patients With Bronchioloalveolar Carcinoma Subtypes: A Southwest Oncology Group Study

Bronchioloalveolar carcinoma (BAC) and adenocarcinomas with BAC features seem to be increasing in incidence, particularly in younger, never-smoking women. Epidermal growth factor receptor (EGFR) inhibitors demonstrated response rates of 20% to 30% in patients with advanced BAC subtypes, but selection methods for patient therapy are not established. EGFR and HER2 gene copy numbers were assessed by fluorescence in situ hybridization (FISH) in 81 patients treated with gefitinib 500 mg/d (Southwest Oncology Group protocol S0126) and were correlated to treatment outcome. Tumors were classified into two main strata: FISH-positive (high polysomy/gene amplification) and FISH-negative (disomy/low polysomy). In 81 patients, the median survival time for EGFR/FISH-negative patients was 8 months and not yet reached for FISH-positive patients (but approaching 18 months; hazard ratio [HR] = 2.02; P = .042). Median progression-free survival time for EGFR/FISH-positive patients was 9 months versus 4 months for the FISH-negative patients (HR = 1.67; P = .072). In multivariate analysis, EGFR copy number by FISH remained a significant predictive factor for survival after accounting for smoking status, sex, histology, and performance status. Fifty-five patients were evaluated for response using Response Evaluation Criteria in Solid Tumors Group, and 12 of 19 EGFR/FISH-positive patients (63%) demonstrated disease control versus 14 (39%) of 36 patients in the FISH-negative group (P = .087). No association was found between HER2 gene copy number and response (n = 39 patients) or survival (n = 56 patients; P > .10). Increased EGFR gene copy number detected by FISH is associated with improved survival after gefitinib therapy in patients with advanced BAC, suggesting FISH methodology can be used to assess survival potential in patients treated with EGFR tyrosine kinase inhibitors.

Increased EGFR gene copy number detected by fish is associated with increased sensitivity to gefitinib in patients with bronchioloalveolar carcinoma (BAC) (S0126)

7030 Background: BAC subtypes are increasing in incidence, particularly in younger, never-smoking women. Studies with EGFR inhibitors have demonstrated response rates of 20–30% in patients (pts) with advanced BAC. However, no methods have been established to select pts for such treatments. Methods: In this study EGFR copy number by fluorescence in situ hybridization (FISH) was assessed and correlated to treatment response and survival. Tumor tissue from 81 pts with advanced stage BAC treated with gefitinib 500mg/day in the SWOG protocol S0126 were analyzed by FISH and classified in two main categories: FISH positive (high polysomy/gene amplification) and FISH negative (disomy, trisomy and low polysomy). Results: Fifty-five pts with measurable disease were evaluated for response using the RECIST criteria. Among 19 FISH positive pts, 12 (63%) had disease control (response or stable disease) versus 14/36 pts (39%) in the FISH negative group (exact p-value=0.099). Eighty-one pts were evaluable for survival, a...

Patterns of recurrence of bronchioloalveolar cell carcinoma after surgical resection: a radiological, histological, and immunohistochemical study

Purpose: Bronchioloalveolar carcinoma (BAC) is a subtype of lung adenocarcinoma whose incidence is raising. Bronchioloalveolar carcinoma has a tendency to involve diffusely the lung. No agreement exists about whether diffuse bronchioloalveolar carcinoma has a multicentric or unicentric origin. The purpose of this work is to evaluate the correlation between intrapulmonary spread of bronchioloalveolar carcinoma and its histologic and immunohistochemical characteristics. Design: Surgical specimens of 20 bronchioloalveolar carcinomas with radiologically proved evolution from focal to diffuse disease were retrieved and reviewed. Patterns of pulmonary spread were defined on the basis of CT and MR imaging examinations. Immunohistochemical studies were performed to investigate the expression of gelatinase A and α2-integrin. Correlation between immunohistochemical results and patterns of pulmonary spread was evaluated. Statistical evaluation was performed by using Fisher Exact Test. Results: Three histological subtypes of bronchioloalveolar carcinoma were found: mucinous (11 cases), non-mucinous (3 cases), and mixed adenocarcinoma with prominent bronchioloalveolar pattern (6 cases). Three patterns of pulmonary spread were depicted radiologically: parenchymal opacification (11 cases), multiple nodules (7 cases) and mixed pattern (2 cases). Eleven out of 12 mucin-producing versus none out of 8 non-mucin producing cancers developed parenchymal opacification. The difference was statistically significant ( P<0.028). A statistically significant difference was also found between the development of parenchymal opacification and the level of α2-integrin: 11 out of 13 tumors with negative α2-integrin versus none out of 7 with positive α2-integrin immunoreactivity ( P>0.033). Conclusions: Diffuse bronchioloalveolar carcinoma may develop from a prior focal cancer. Mucinous subtype is the most prone to develop diffuse disease with parenchymal opacification, probably representing aerogenous spread. Low levels of α2-integrin receptors were found in bronchioloalveolar carcinoma which developed parenchymal opacification.

Mixed mucinous-type and non-mucinous-type adenocarcinoma of the lung: immunohistochemical examination and K- ras gene mutation.

Mucinous-type adenocarcinoma and non-mucinous-type adenocarcinoma are known to be the representative histological subtypes of bronchioloalveolar carcinoma. Mucinous-type adenocarcinoma is also known to carry abnormalities of the K- ras gene at high frequency. However, the mixed subtype of the both mucinous-type and non-mucinous-type adenocarcinoma (mixed-type) has not been analyzed in detail, although its existence has been reported in a few papers. In this study we carried out immunohistochemical and molecular biological analyses of 15 examples of the mixed-type, in comparison with 11 cases of mucinous-type and 21 cases of non-mucinous-type adenocarcinoma. Immunohistochemically, lysozyme - one of the specific markers of mucinous-type adenocarcinoma - was not stained in the mucinous component of the mixed-type. K- ras gene mutations were detected only in mucinous-type (73%) and non-mucinous-type (10%) adenocarcinomas and not in either the mucinous or non-mucinous component of the mixed-type (0%). Therefore, although mixed-type adenocarcinomas consist of tumor cells showing both mucinous and non-mucinous morphology, the mucinous component of this type differs from mucinous-type adenocarcinoma in terms of immunohistochemical features and K- ras gene alteration.

Primary lung tumors in mice as an aid for understanding, preventing, and treating human adenocarcinoma of the lung

Primary lung tumors in mice have morphologic, histogenic, and molecular features similar to human lung adenocarcinoma, and in particular, the bronchiolo-alveolar carcinoma subtype. Because of this, and because of the genetic homology between man and mouse and the ease of genetic manipulations in mice, this model system is receiving intense research attention. This review is intended to be informative to clinical investigators, and describes features of this model, how it is being used for translational research, and points out additional avenues of study that could have practical benefits, such as application for identifying novel therapeutic strategies.

Expression and significance of extracellular matrix and cell adhesion molecule in bronchiolo-alveolar carcinoma

To study the expressing features and significance of extracellular matrix(ECM)-laminin(LN),collagen IV(Coll IV),fibronectin(FN) and cell adhesion molecule(A-CAM) in the three subtypes of the bronchiolo-alveolar carcinoma(BAC) and conventional pulmonary adenocarcinoma(CPA). Using immunohistochemical LSAB technique,the distribution and expression of ECM and A-CAM were examined in 50 cases of BAC(including 14 mucinous,22 nonmucinous and 14 sclerosing) and 6 of CPA. LN,Coll IV and FN in the basement membrane were stained as uninterrupted narrow line in the mucinous BAC and the pulmonary parenchyma adjacent to the carcinoma. In the nonmucinous BAC,ECM showed as irregular tram-track like double layers. The peripheral areas of the sclerosing BAC was virtually identical in staining pattern to the nonmucinous,and the central areas,which showed disrupted or absent in the basement membrane surrounding the glands embedded in the fibrous stroma,was similar to that of CPA. The frequency of A-CAM expression in BAC and CPA was 60%(30/50) and 83% (5/6) respectively, with no significant correlation found(P>0.05). The percentage of A-CAM in three BAC subtypes was 43%(6/14),55%(12/22) and 86%(12/14),which appeared as increased tendency. There was a significant difference between the mucinous and sclerosing BAC(P<0.05),while the sclerosing BAC was close to CPA. On the basis of the distribution and expression of ECM and A-CAM,BAC should be taken as a subtype of CPA. The mucinous BAC may be a real BAC. Perhaps there is some differentiation correlation among three subtypes of BAC and CPA.

FHIT and p53 gene abnormalities in bronchioloalveolar carcinomas. Correlations with clinicopathological data and K-ras mutations.

Bronchioloalveolar carcinoma (BAC) is a particular type of adenocarcinoma of the lung which accounts for up to 9 per cent of pulmonary malignancies. The aetiology and pathogenesis of this unique neoplastic disease are still unclear. Three histological subtypes of BAC have been recognized: mucinous, non-mucinous, and sclerosing. Of these, mucinous and sclerosing BAC have a worse prognosis than non-mucinous tumours. The different morphological patterns and clinical outcomes of the subtypes of BAC suggest differences in their biological behaviour. Previous reports have shown that the mucinous form of BAC is characterized by constant mutations at codon 12 of the K-ras gene, whereas the other two histotypes show a frequency of K-ras mutations which is not different from that observed in conventional lung adenocarcinomas. The present study of a series of 51 BACs, previously investigated for K-ras gene mutations, has evaluated the status of two other genes, p53 and FHIT, known to be frequently altered in non-small cell lung cancer. Loss of heterozygosity at microsatellite-containing loci located within the FHIT gene was observed in 22 (43 per cent) BACs. The distribution of FHIT gene abnormalities was not statistically different in the three histological subtypes. p53 mutations were present in 13 (32 per cent) non-mucinous/sclerosing BACs, while no mutations were seen in mucinous tumours (P = 0.039). Correlations with clinicopathological parameters showed that p53 mutations in BACs are associated with more aggressive tumours. No correlations were observed between FHIT or K-ras gene abnormalities and clinicopathological data. In conclusion, these results indicate that FHIT alterations are frequently involved in BAC tumourigenesis and that genetic changes in the p53 and K-ras genes can distinguish between different histotypes of BAC.