Worldwide Esophageal Cancer Collaboration: pathologic staging data.

We report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for patients with pathologically staged cancer of the esophagus and esophagogastric junction after resection or ablation with no preoperative therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted de-identified data using standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 13,300 patients, 5,631 had squamous cell carcinoma, 7,558 adenocarcinoma, 85 adenosquamous carcinoma, and 26 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (51%), little weight loss (1.8 kg), 0-2 ECOG performance status (83%), and a history of smoking (70%). Cancers were pT1 (24%), pT2 (15%), pT3 (50%), pN0 (52%), pM0 (93%), and pG2-G3 (78%); most involved distal esophagus (71%). Non-risk-adjusted survival for both squamous cell carcinoma and adenocarcinoma was monotonic and distinctive across pTNM. Survival was more distinctive for adenocarcinoma than squamous cell carcinoma when pT was ordered by pN. Survival for pTis-1 adenocarcinoma was better than for squamous cell carcinoma, although monotonic and distinctive for both. WECC pathologic staging data is improved over that of the 7th edition, with more patients studied and patient and cancer variables collected. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics, and should direct 9th edition data collection. However, the role of pure pathologic staging as the principal point of reference for esophageal cancer staging is waning.

Worldwide Esophageal Cancer Collaboration: clinical staging data.

To address uncertainty of whether clinical stage groupings (cTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for clinically staged patients from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 22,123 clinically staged patients, 8,156 had squamous cell carcinoma, 13,814 adenocarcinoma, 116 adenosquamous carcinoma, and 37 undifferentiated carcinoma. Patients were older (62 years) men (80%) with normal body mass index (18.5-25 mg/kg2 , 47%), little weight loss (2.4 ± 7.8 kg), 0-1 ECOG performance status (67%), and history of smoking (67%). Cancers were cT1 (12%), cT2 (22%), cT3 (56%), cN0 (44%), cM0 (95%), and cG2-G3 (89%); most involved the distal esophagus (73%). Non-risk-adjusted survival for squamous cell carcinoma was not distinctive for early cT or cN; for adenocarcinoma, it was distinctive for early versus advanced cT and for cN0 versus cN+. Patients with early cancers had worse survival and those with advanced cancers better survival than expected from equivalent pathologic categories based on prior WECC pathologic data. Thus, clinical and pathologic categories do not share prognostic implications. This makes clinically based treatment decisions difficult and pre-treatment prognostication inaccurate. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient characteristics, cancer categories, and treatment characteristics and should direct 9th edition data collection.

Worldwide Esophageal Cancer Collaboration: neoadjuvant pathologic staging data.

To address uncertainty of whether pathologic stage groupings after neoadjuvant therapy (ypTNM) for esophageal cancer share prognostic implications with pathologic groupings after esophagectomy alone (pTNM), we report data-simple descriptions of patient characteristics, cancer categories, and non-risk-adjusted survival-for pathologically staged cancers after neoadjuvant therapy from the Worldwide Esophageal Cancer Collaboration (WECC). Thirty-three institutions from six continents submitted data using variables with standard definitions: demographics, comorbidities, clinical cancer categories, and all-cause mortality from first management decision. Of 7,773 pathologically staged neoadjuvant patients, 2,045 had squamous cell carcinoma, 5,686 adenocarcinoma, 31 adenosquamous carcinoma, and 11 undifferentiated carcinoma. Patients were older (61 years) men (83%) with normal (40%) or overweight (35%) body mass index, 0-1 Eastern Cooperative Oncology Group performance status (96%), and a history of smoking (69%). Cancers were ypT0 (20%), ypT1 (13%), ypT2 (18%), ypT3 (44%), ypN0 (55%), ypM0 (94%), and G2-G3 (72%); most involved the distal esophagus (80%). Non-risk-adjusted survival for yp categories was unequally depressed, more for earlier categories than later, compared with equivalent categories from prior WECC data for esophagectomy-alone patients. Thus, survival of patients with ypT0-2N0M0 cancers was intermediate and similar regardless of ypT; survival for ypN+ cancers was poor. Because prognoses for ypTNM and pTNM categories are dissimilar, prognostication should be based on separate ypTNM categories and groupings. These data will be the basis for the 8th edition cancer staging manuals following risk adjustment for patient, cancer, and treatment characteristics and should direct 9th edition data collection.

Outcomes of induction chemotherapy followed by chemoradiation using intensity-modulated radiation therapy for esophageal adenocarcinoma.

This study looks at toxicity and survival data when chemoradiation (CRT) is delivered using intensity-modulated radiation therapy (IMRT) after induction chemotherapy. Forty-one patients with esophageal adenocarcinoma treated with IMRT from March 2007 to May 2009 at Memorial Sloan-Kettering Cancer Center were analyzed. All patients received induction chemotherapy prior to CRT. Thirty-nine percent (n = 16) of patients underwent surgical resection less than 4 months after completing CRT. Patients were predominantly male (78%), with a median age of 68 years (range 32-85 years). The majority of acute treatment-related toxicity was hematologic or gastrointestinal, with 17% of patients having grade 3+ hematologic toxicity and 12% of patients having grade 3+ gastrointestinal toxicity. Only two patients developed grade 2-3 pneumonitis (5%) and 5 patients experienced post-operative pulmonary complications (29%). Eight patients (20%) required a treatment break. With a median follow up of 41 months for surviving patients, 2-year overall survival was 61%, and the cumulative incidences of local failure (LF) and distant metastases were 40% and 51%, respectively. This rate of LF was reduced to 13% in patients who underwent surgical resection. Surgery and younger age were significant predictors of decreased time to LF on univariate analysis. Induction chemotherapy followed by CRT using IMRT in the treatment of esophageal cancer is well tolerated and is not associated with an elevated risk of postoperative pulmonary complications. The use of IMRT may allow for integration of more intensified systemic therapy or radiation dose escalation for esophageal adenocarcinoma, ultimately improving outcomes for patients with this aggressive disease.

Clinical tools do not predict pathological complete response in patients with esophageal squamous cell cancer treated with definitive chemoradiotherapy.

Chemoradiotherapy for locally advanced esophageal squamous cell carcinoma is associated with high rates of pathological complete response. A pathological complete response is recognized to be an important predictor of improved survival, to the extent that observation rather than surgery is advocated by some in patients with presumed pathological complete response based on their clinical response. The goal of this study was to look at the ability of clinical variables to predict pathological complete response after chemoradiotherapy for locally advanced esophageal squamous cell carcinoma. We reviewed retrospectively patients with locally advanced esophageal squamous cell carcinoma who underwent chemoradiotherapy followed by surgery and compared those with pathological complete response to patients with residual disease. Between January 1996 and December 2010, 116 patients met inclusion criteria. Fifty-six percent of patients had a pathological complete response and a median survival of 128.1 months versus 28.4 months in patients with residual disease. When compared with patients with residual disease, patients with a pathological complete response had a lower post-neoadjuvant positron emission tomography (PET) maximum standardized uptake value (SUVmax), a larger decrease in PET SUVmax, a less thick tumor on post-chemoradiotherapy computed tomography and a higher rate of normal appearing post-chemoradiotherapy endoscopy with benign biopsy of the tumor bed. However, none of these characteristics alone was able to correctly identify patients with a pathological complete response, and none has significant specificity. Although the rate of pathological complete response after chemoradiotherapy is high in patients with esophageal squamous cell carcinoma, the ability of identifying patients with pathological complete response is limited. A reduction of the PET SUVmax by >70%, a normal appearing endoscopic examination, and no residual disease on biopsy all were seen in >65% of the patients with a pathological complete response. Even if these findings were unable to confirm the absence of residual disease in the primary tumor, they can help guide expectant management in high-risk patients.

Surgical implications of the new IASLC/ATS/ERS adenocarcinoma classification.

A new adenocarcinoma classification was recently introduced by a joint working group of the International Association for the Study of Lung Cancer (IASLC), American Thoracic Society (ATS) and European Respiratory Society (ERS). A distinction is made between pre-invasive lesions, and minimally invasive and invasive adenocarcinoma. The confusing term "bronchioloalveolar carcinoma" is not used any more and new subcategories include adenocarcinoma in situ and minimally invasive adenocarcinoma. Due to a renewed interest in screen-detected nodules and early-stage lung cancers of <2 cm, this classification also has profound implications for thoracic surgeons. In this article, surgical topics are discussed: the role of a minimally invasive approach, especially video-assisted thoracic surgery, limited resection for early-stage lung cancer, the extent of lymph node dissection, the accuracy of intraoperative frozen section analysis, management of multiple lung nodules and prognostic factors in operated patients. Specific key issues are presented based on the current evidence and areas of surgical uncertainty are defined providing a basis for further studies. Thoracic surgeons will play a major role in the application and global introduction of this new adenocarcinoma classification. The remaining controversies regarding the precise diagnosis and management of early-stage lesions will have to be resolved by multidisciplinary and international collaboration.

Worldwide esophageal cancer collaboration.

The aim of this study is to report assemblage of a large multi-institutional international database of esophageal cancer patients, patient and tumor characteristics, and survival of patients undergoing esophagectomy alone and its correlates. Forty-eight institutions were approached and agreed to participate in a worldwide esophageal cancer collaboration (WECC), and 13 (Asia, 2; Europe, 2; North America, 9) submitted data as of July 1, 2007. These were used to construct a de-identified database of 7884 esophageal cancer patients who underwent esophagectomy. Four thousand six hundred and twenty-seven esophagectomy patients had no induction or adjuvant therapy. Mean age was 62 +/- 11 years, 77% were men, and 33% were Asian. Mean tumor length was 3.3 +/- 2.5 cm, and esophageal location was upper in 4.1%, middle in 27%, and lower in 69%. Histopathologic cell type was adenocarcinoma in 60% and squamous cell in 40%. Histologic grade was G1 in 32%, G2 in 33%, G3 in 35%, and G4 in 0.18%. pT classification was pTis in 7.3%, pT1 in 23%, pT2 in 16%, pT3 in 51%, and pT4 in 3.3%. pN classification was pN0 in 56% and pN1 in 44%. The number of lymph nodes positive for cancer was 1 in 12%, 2 in 8%, 3 in 5%, and >3 in 18%. Resection was R0 in 87%, R1 in 11%, and R2 in 3%. Overall survival was 78, 42, and 31% at 1, 5, and 10 years, respectively. Unlike single-institution studies, in this worldwide collaboration, survival progressively decreases and is distinctively stratified by all variables except region of the world. A worldwide esophageal cancer database has been assembled that overcomes problems of rarity of this cancer. It reveals that survival progressively (monotonically) decreased and was distinctively stratified by all variables except region of the world. Thus, it forms the basis for data-driven esophageal cancer staging. More centers are needed and encouraged to join WECC.

Small-cell carcinoma of the esophagus and gastroesophageal junction: review of the Memorial Sloan-Kettering experience.

BACKGROUND: Esophageal small-cell carcinoma (SCC) is rare, highly malignant and the optimal treatment approach has not been defined. PATIENTS AND METHODS: We report the largest single-institution retrospective review of patients with esophageal and gastroesophageal (GE) junction SCC. RESULTS: Twenty-five patients were identified, with complete records available for 22. Eighty-two percent were male, 82% had pure SCC histology and 86% of tumors were in the lower esophagus or GE junction. On the basis of the Veterans' Administration Lung Study Group criteria, 14 patients (64%) presented with limited disease (LD). Median survival was 19.8 months (range, 1.5 months to 11.2+ years); for LD patients, 22.3 months (range, 6 months to 11.2+ years); for extensive disease (ED) patients, 8.5 months (range, 1.5 months to 2.2 years, P = 0.02). With a median follow-up of 38 months, six patients (27%) are alive, one with ED and five with LD. Two LD patients are alive and free of disease for >5 years. Four of the five LD patients who are long-term survivors received induction chemotherapy followed by chemoradiotherapy without surgery. CONCLUSIONS: Our data indicate that patients with LD esophageal SCC treated with induction chemotherapy followed by consolidative chemoradiation can achieve long-term survival. The contribution of surgery remains unclear.

New Insights on Diagnostic Reproducibility of Biphasic Mesotheliomas: A Multi-Institutional Evaluation by the International Mesothelioma Panel From the MESOPATH Reference Center.

INTRODUCTION: The 2015 WHO classification of tumors categorized malignant mesothelioma into epithelioid, biphasic (BMM), and sarcomatoid (SMM) for prognostic relevance and treatment decisions. The survival of BMM is suspected to correlate with the amount of the sarcomatoid component. The criteria for a sarcomatoid component and the interobserver variability between pathologists for identifying this component are not well described. In ambiguous cases, a "transitional" (TMM) subtype has been proposed but was not accepted as a specific subtype in the 2015 WHO classification. The aims of this study were to evaluate the interobserver agreement in the diagnosis of BMM, to determine the nature and the significance of TMM subtype, and to relate the percentage of sarcomatoid component with survival. The value of staining for BRCA-1-associated protein (BAP1) and CDKN2A(p16) fluorescence in situ hybridization (FISH) were also assessed with respect to each of the tumoral components. METHODS: The study was conducted by the International Mesothelioma Panel supported by the French National Cancer Institute, the network of rare cancer (EURACAN) and in collaboration with the International Association for the Study of Lung Cancer (IASLC). The patient cases include a random group of 42 surgical biopsy samples diagnosed as BMM with evaluation of SMM component by the French Panel of MESOPATH experts was selected from the total series of 971 BMM cases collected from 1998 to 2016. Fourteen international pathologists with expertise in mesothelioma reviewed digitally scanned slides (hematoxylin and eosin - stained and pan-cytokeratin) without knowledge of prior diagnosis or outcome. Cases with at least 7 of 14 pathologists recognizing TMM features were selected as a TMM group. Demographic, clinical, histopathologic, treatment, and follow-up data were retrieved from the MESOBANK database. BAP1 (clone C-4) loss and CDKN2A(p16) homozygous deletion (HD) were assessed by immunohistochemistry (IHC) and FISH, respectively. Kappa statistics were applied for interobserver agreement and multivariate analysis with Cox regression adjusted for age and gender was performed for survival analysis. RESULTS: The 14 panelists recorded a total of 544 diagnoses. The interobserver correlation was moderate (weighted Kappa = 0.45). Of the cases originally classified as BMM by MESOPATH, the reviewers agreed in 71% of cases (385 of 544 opinions), with cases classified as pure epithelioid in 17% (93 of 544), and pure sarcomatoid in 12% (66 of 544 opinions). Diagnosis of BMM was made on morphology or IHC alone in 23% of the cases and with additional assessment of IHC in 77% (402 of 544). The median overall survival (OS) of the 42 BMM cases was 8 months. The OS for BMM was significantly different from SMM and epithelioid malignant mesothelioma (p < 0.0001). In BMM, a sarcomatoid component of less than 80% correlated with a better survival (p = 0.02). There was a significant difference in survival between BMM with TMM showing a median survival at 6 months compared to 12 months for those without TMM (p < 0.0001). BAP1 loss was observed in 50% (21 of 42) of the total cases and in both components in 26%. We also compared the TMM group to that of more aggressive patterns of epithelioid subtypes of mesothelioma (solid and pleomorphic of our large MESOPATH cohort). The curve of transitional type was persistently close to the OS curve of the sarcomatoid component. The group of sarcomatoid, transitional, and pleomorphic mesothelioma were very close to each other. We then considered the contribution of BAP1 immunostaining and loss of CDKN2A(p16) by FISH. BAP1 loss was observed in 50% (21 of 41) of the total cases and in both component in 27% of the cases (11 of 41). There was no significant difference in BAP1 loss between the TMM and non-TMM groups. HD CDKN2A(p16) was detected in 74% of the total cases with no significant difference between the TMM and non-TMM groups. In multivariate analysis, TMM morphology was an indicator of poor prognosis with a hazard ratio = 3.2; 95% confidence interval: 1.6 - 8.0; and p = 0.003 even when compared to the presence of HD CDKN2A(p16) on sarcomatoid component (hazard ratio = 4.5; 95% confidence interval: 1.2 - 16.3, p = 0.02). CONCLUSIONS: The interobserver concordance among the international mesothelioma and French mesothelioma panel suggests clinical utility for an updated definition of biphasic mesothelioma that allows better stratification of patients into risk groups for treatment decisions, systemic anticancer therapy, or selection for surgery or palliation. We also have shown the usefulness of FISH detection of CDKN2A(p16) HD compared to BAP1 loss on the spindle cell component for the separation in ambiguous cases between benign florid stromal reaction from true sarcomatoid component of biphasic mesothelioma. Taken together our results further validate the concept of transitional pattern as a poor prognostic indicator.

The epidermal growth factor receptor and its ligands as therapeutic targets in human tumors.

The epidermal growth factor receptor (EGFR) is detected on many non-haematopoietic tissues and is frequently overexpressed in human tumors. With its ligand, TGF-alpha, it forms a well-defined autocrine growth loop. Several clinical approaches, using EGFR as a therapeutic target, are being investigated, particularly monoclonal antibodies combined with chemotherapy, and pharmacological inhibition of downstream components of the EGFR signaling pathway.

Minimally invasive localization of oncolytic herpes simplex viral therapy of metastatic pleural cancer.

Herpes simplex virus-1 (HSV-1) oncolytic therapy and gene therapy are promising treatment modalities against cancer. NV1066, one such HSV-1 virus, carries a marker gene for enhanced green fluorescent protein (EGFP). The purpose of this study was to determine whether NV1066 is cytotoxic to lung cancer and whether EGFP is a detectable marker of viral infection in vitro and in vivo. We further investigated whether EGFP expression in infected cells can be used to localize the virus and to identify small metastatic tumor foci (<1 mm) in vivo by means of minimally invasive endoscopic systems equipped with fluorescent filters. In A549 human lung cancer cells, in vitro viral replication was determined by plaque assay, cell kill by LDH release assay, and EGFP expression by flow cytometry. In vivo, A549 cells were injected into the pleural cavity of athymic mice. Mice were treated with intrapleural injection of NV1066 or saline and examined for EGFP expression in tumor deposits using a stereomicroscope or a fluorescent thoracoscopic system. NV1066 replicated in, expressed EGFP in infected cells and killed tumor cells in vitro. In vivo, treatment with intrapleural NV1066 decreased pleural disease burden, as measured by chest wall nodule counts and organ weights. EGFP was easily visualized in tumor deposits, including microscopic foci, by fluorescent thoracoscopy. NV1066 has significant oncolytic activity against a human NSCLC cell line and is effective in limiting the progression of metastatic disease in an in vivo orthotopic model. By incorporating fluorescent filters into endoscopic systems, a minimally invasive means for diagnosing small metastatic pleural deposits and localization of viral therapy for thoracic malignancies may be developed using the EGFP marker gene inserted in oncolytic herpes simplex viruses.

Virally-directed fluorescent imaging (VFI) can facilitate endoscopic staging.

BACKGROUND: Replication-competent, tumor specific herpes simplex virus NV1066 expresses green fluorescent protein (GFP) in infected cancer cells. We sought to determine the feasibility of GFP-guided imaging technology in the intraoperative detection of small tumor nodules. METHODS: Human cancer cell lines were infected with NV1066 at multiplicities of infection of 0.01, 0.1 and 1. Cancer cell specific infectivity, vector spread and GFP signal intensity were measured by flow cytometry and time-lapse digital imaging (in vitro); and by use of a stereomicroscope and endoscope equipped with a fluorescent filter (in vivo). RESULTS: NV1066 infected all cancer cell lines and expressed GFP at all MOIs. GFP signal was significantly higher than the autofluorescence of normal cells. One single dose of NV1066 spread within and across body cavities and selectively infected tumor nodules sparing normal tissue. Tumor nodules undetectable by conventional thoracoscopy and laparoscopy were identified by GFP fluorescence. CONCLUSION: Virally-directed fluorescent imaging (VFI) is a real-time novel molecular imaging technology that has the potential to enhance the intraoperative detection of endoluminal or endocavitary tumor nodules.

High telomerase activity in primary lung cancers: association with increased cell proliferation rates and advanced pathologic stage.

BACKGROUND: Telomerase enzyme activity is not detected in most normal cells, a phenomenon believed to be associated with limitations on cellular proliferation. Since this activity is detected in nearly all human tumors, including non-small-cell lung cancers, it has been suggested that telomerase activation may be coupled to acquisition of the malignant phenotype. In this study, we determined whether telomerase activity was associated with tumor pathologic stage, tumor cell proliferation rates, and clinical outcome in a cohort of patients with resected non-small-cell lung cancer for whom long-term follow-up was available. METHODS: Primary tumor specimens from 99 patients treated with surgery alone and six patients treated with surgery after chemotherapy were analyzed. Telomerase activity was measured by means of a modified Telomeric Repeat Amplification Protocol (TRAP) assay. Southern blot analysis of terminal restriction fragments was used to evaluate telomere length. Immunohistochemical analysis of Ki-67, a proliferation-associated nuclear antigen, was used to assess tumor cell proliferation. RESULTS: Telomerase activity was detected in 84 of the 99 tumors treated with surgery alone; this activity was not detected in specimens of adjacent, benign lung tissue. Telomerase was detected in only three of six tumors resected after chemotherapy. For the surgery-alone group, statistically significant positive associations were found between the level of telomerase activity and tumor stage, lymph node metastasis, pathologic TNM (tumor-node-metastasis) stage, and Ki-67 immunostaining; a statistically significant inverse association was found between telomerase activity and patient age. No statistically significant differences in telomere length were found in relation telomerase activity or pathologic stage. Telomerase activity was not found to be associated with clinical outcome in a multivariate Cox proportional hazards analysis adjusted for tumor stage and lymph node status. CONCLUSIONS: High telomerase activity is detected frequently in primary non-small-cell lung cancers that exhibit high tumor cell proliferation rates and advanced pathologic stage.

Cyclin D1 proteolysis: a retinoid chemoprevention signal in normal, immortalized, and transformed human bronchial epithelial cells.

BACKGROUND: Retinoids (derivatives of vitamin A) are reported to reduce the occurrence of some second primary cancers, including aerodigestive tract tumors. In contrast, beta-carotene does not reduce the occurrence of primary aerodigestive tract cancers. Mechanisms explaining these effective retinoid and ineffective carotenoid chemoprevention results are poorly defined. Recently, the all-trans-retinoic acid (RA)-induced proteolysis of cyclin D1 that leads to the arrest of cells in G1 phase of the cell cycle was described in human bronchial epithelial cells and is a promising candidate for such a mechanism. In this study, we have investigated this proteolysis as a common signal used by carotenoids or receptor-selective and receptor-nonselective retinoids. METHODS: We treated cultured normal human bronchial epithelial cells, immortalized human bronchial epithelial cells (BEAS-2B), and transformed human bronchial epithelial cells (BEAS-2BNNK) with receptor-selective or receptor-nonselective retinoids or with carotenoids and studied the effects on cell proliferation by means of tritiated thymidine incorporation and on cyclin D1 expression by means of immunoblot analysis. We also examined whether calpain inhibitor I, an inhibitor of the 26S proteasome degradation pathway, affected the decline (i.e., proteolysis) of cyclin D1. RESULTS: Receptor-nonselective retinoids were superior to the carotenoids studied in mediating the decline in cyclin D1 expression and in suppressing the growth of bronchial epithelial cells. Retinoids that activated retinoic acid receptor beta or retinoid X receptor pathways preferentially led to a decrease in the amount of cyclin D1 protein and a corresponding decline in growth. The retinoid-mediated degradation of cyclin D1 was blocked by cotreatment with calpain inhibitor I. CONCLUSIONS: Retinoid-dependent cyclin D1 proteolysis is a common chemoprevention signal in normal and neoplastic human bronchial epithelial cells. In contrast, carotenoids did not affect cyclin D1 expression. Thus, the degradation of cyclin D1 is a candidate intermediate marker for effective retinoid-mediated cancer chemoprevention in the aerodigestive tract.

Aberrant expression of p53 or the epidermal growth factor receptor is frequent in early bronchial neoplasia and coexpression precedes squamous cell carcinoma development.

New strategies are needed for the detection and treatment of lung cancer and must derive from a fuller understanding of lung carcinogenesis. Frequent molecular genetic abnormalities occur in non-small cell lung cancer (NSCLC), but little is known about which of these precede an invasive carcinoma. We examined the expression of p53, epidermal growth factor receptor (EGFR), and transforming growth factor alpha, the most common molecular genetic abnormalities in NSCLC, in preneoplastic bronchial lesions. Primary NSCLC and associated bronchial lesions were identified by retrospective review of resected tumors at this center. Expression in the invasive carcinomas, the associated bronchial lesions, and normal lung were contrasted using immunohistochemistry. Thirty-four NSCLC associated with 62 bronchial lesions were identified. The invasive tumors included 15 squamous cell carcinomas (SCCs) and 19 non-SCCs. Bronchial lesions included areas of squamous metaplasia (n = 14), inflammatory atypia (n = 19), dysplasia (n = 17), and carcinoma in situ (n = 12). Nineteen (56%) NSCLC and 10 (16%) bronchial lesions exhibited aberrant p53 immunostaining, whereas 18 (53%) NSCLC and 30 (48%) bronchial lesions showed abnormal EGFR immunostaining. Positive staining for transforming growth factor alpha was seen in 16 (47%) NSCLC but occurred inconsistently in the bronchial lesions and in normal bronchial epithelium. Only bronchial lesions associated with squamous cell carcinomas exhibited staining for p53. Aberrant EGFR expression was not associated with a specific type of invasive carcinoma or with specific preneoplastic lesions, although there was a trend toward increased expression in dysplasia and carcinoma in situ relative to metaplasia and atypia. All but one of the NSCLC simultaneously showing aberrant p53 and EGFR staining were SCC. We conclude that: (a) transforming growth factor alpha is variably expressed in normal respiratory epithelium as well as reactive and preneoplastic bronchial lesions; (b) p53 expression is seen in preneoplastic bronchial lesions but is not present in reactive or metaplastic epithelium; (c) aberrant EGFR expression occurs in both reactive and preinvasive bronchial lesions and may be an early marker of neoplastic transformation; and (d) the simultaneous aberrant expression of EGFR and p53 occurs predominantly in SCC and their associated bronchial lesions. These findings indicate that aberrant expression of p53 or the EGFR is frequent in bronchial neoplasia, and coexpression may predispose to the development of squamous cell carcinomas of the lung.

Overexpression of cyclins D1 and E is frequent in bronchial preneoplasia and precedes squamous cell carcinoma development.

Increased protein expression of the G1 cyclins D1 and E is reported in invasive non-small cell lung carcinoma. However, during transformation of the bronchial epithelium, overexpression of these species occurs, and their relationship to aberrant expression of p53 and retinoblastoma (Rb) has not been described previously. To determine the expression of these cell cycle regulators during the development of invasive squamous cell carcinoma (SCC) of the lung, the immunohistochemical expression patterns in normal bronchial epithelium (n = 36), squamous metaplasia (SM; n = 28), and epithelial atypia (n = 34) were compared with that in low-grade dysplasia (LGD; n = 17), high-grade bronchial dysplasia (HGD; n = 30), and SCC (n = 36). Monoclonal anti-p53 Pab1801, polyclonal anti-cyclin D1 DCS6, monoclonal anti-cyclin E HE12, and monoclonal anti-Rb OP-66 antibodies were used. Cyclin D1 was not expressed in normal bronchial epithelium but was detected in 7% of SMs, 15% of atypias; 18% of LGDs, 47% of HGDs, and 42% of SCCs. Cyclin E was not detected in normal epithelium (n = 24), SM (n = 16), or LGD (n = 12), but it was found in 9% of atypias (2 of 22), 33% of HGDs (7 of 21), and 54% of SCCs (13 of 24). p53 was not expressed in normal epithelium, SM, and LGD, but it was overexpressed in 6% of atypias, 53% of HGDs, and 61% of SCCs. Abnormal Rb expression was found only in 2 of 36 cases of SCC. A total of 91% of HGDs and 92% of SCCs exhibited overexpression of at least one of the p53, cyclin D1, or cyclin E species. However, no link was observed between overexpression of p53 and the overexpressed G1 cyclins in preneoplastic lesions. Overexpression of cyclin D1, cyclin E, and p53 occurs frequently and independently in pulmonary SCC and is detected in lesions before the development of invasive carcinoma. In contrast, altered Rb expression is a late and infrequent event in squamous cell carcinogenesis.

Aberrant p53 expression predicts clinical resistance to cisplatin-based chemotherapy in locally advanced non-small cell lung cancer.

The development of cisplatin-based induction chemotherapy followed by surgical resection or radiation has improved the poor prognosis of stage III non-small cell lung cancer (NSCLC). In vitro studies indicate that p53 can modulate cisplatin-induced cytotoxicity, but the molecular genetic features determining response or resistance to cisplatin in vivo must be defined. For this reason, tumor specimens from 52 patients with stage IIIA NSCLC entered in a prospective clinical trial of cisplatin-based induction chemotherapy followed by surgical resection were examined for p53 expression by immunohistochemical staining before and after induction chemotherapy. p53 expression was correlated with clinical and pathological response using Fisher's exact test. No correlation was established between p53 expression and clinical response because 47 of the 52 patients studied had a major response. However, a significant association was observed between aberrant p53 expression and resistance to chemotherapy as assessed by pathological response. Only 3 of the 20 patients whose tumors exhibited a high level (+ + to + + + +) of p53 staining experienced a major (+ + + to + + + +) pathological response to chemotherapy. Only 7 of 52 cases examined before and after chemotherapy treatment exhibited a change in the level of p53 expression after cisplatin-based chemotherapy. These results indicate that cisplatin alters p53 expression infrequently and suggest a direct link between aberrant p53 expression and resistance to cisplatin-based chemotherapy in NSCLC.

Differential expression of the epidermal growth factor receptor and its ligands in primary non-small cell lung cancers and adjacent benign lung.

The epidermal growth factor receptor (EGFR) and one of its ligands, transforming growth factor alpha (TGF-alpha), are thought to function as a potential autocrine loop in non-small cell lung cancer (NSCLC). However, the expression pattern of EGFR and the TGF-alpha-related ligands have not been fully characterized in primary NSCLC and adjacent benign lung tissue. For this reason, we comprehensively examined the coexpression and differential expression of EGFR and its ligands, TGF-alpha, epidermal growth factor (EGF), and amphiregulin (AR), by Northern analysis, in paired samples of primary tumors and uninvolved lung. For those RNA species overexpressed in malignant lung, single cell expression patterns were studied by immunohistochemistry. Specimens were obtained from 57 consecutive patients who underwent resection of carefully staged resectable NSCLC and were followed prospectively. Most (112 of 114) tissue samples yielded high-quality RNA. EGFR was expressed in 82 of 88 (93%) tissue samples, while TGF-alpha was expressed in 62 of 72 (86%) samples, and AR was expressed in 64 of 70 (92%) samples. EGF was unexpressed in total cellular RNA in both tumor and uninvolved lung. In a comparison of RNA expression patterns in tumors and uninvolved lung, overexpression of EGFR was found in 45% (22 of 44) of tumors, while overexpression of TGF-alpha was seen in 61% (22 of 36) of tumors, and decreased expression of AR was seen in 63% (22 of 35) of tumors. Cell type and stage did not influence differential expression, indicating that this is a frequent event in primary NSCLC. Simultaneous overexpression of EGFR and TGF-alpha was seen in only 38% of tumors. Simultaneous overexpression of EGFR and decreased expression of AR were seen in only 21% of tumors. Thus far, the differential expression of EGFR, TGF-alpha, and AR does not correlate with either disease-free or overall survival. These findings indicate that histologically dissimilar tumors can express similar components of autocrine or paracrine growth factor loops. Differential expression of EGFR and its ligands in tumor specimens compared to uninvolved lung is a common event in NSCLC and may participate in tumor growth without necessarily influencing tumor progression or histology.

A multi-institutional study confirms the presence and expression of simian virus 40 in human malignant mesotheliomas.

Exposure to the carcinogen asbestos is a major factor in the development of malignant mesothelioma. However, not all mesotheliomas are associated with asbestos exposure, and only a small minority of people exposed to asbestos develop mesothelioma. Therefore, the identification of the cofactors that render certain individuals more susceptible to asbestos or that cause mesothelioma in people not exposed to asbestos has been a major priority of the International Mesothelioma Interest Group. The possible association of SV40 with mesothelioma was recently discussed in a special session at the Fourth International Mesothelioma Interest Group Conference, and it was decided to conduct a multi-institutional study to independently verify the presence of this tumor virus in mesotheliomas. We report the results of this investigation: (a) DNA and protein analyses revealed SV40 sequences and SV40 large T antigen expression in 10 of 12 mesotheliomas tested (83%); and (b) electron microscopy demonstrated variable amounts of asbestos fibers in 5 (71%) of 7 corresponding lung tissues available for analysis. Our results demonstrate that SV40 DNA is frequently present and expressed in mesotheliomas in the United States. Because our data demonstrate that some patients test positive for both SV40 and asbestos, the possibility that these two carcinogens interact should be investigated in future studies.

Growth suppression of transformed human bronchial epithelial cells by all-trans-retinoic acid occurs through specific retinoid receptors.

The retinoids are reported to chemoprevent second aerodigestive tract cancers in patients with prior lung or head and neck cancers. Since those retinoids already examined in clinical trials do not induce major clinical responses in lung cancers, it is hypothesized that the beneficial chemoprevention activity in lung neoplasias occurs within 'fields' of carcinogen-transformed epithelial cells. To begin to investigate this retinoid action during lung carcinogenesis, the BZR-T33 ras transformed human bronchial epithelial cell line that grows in an anchorage independent manner was examined. This study reports, as compared to controls, that all-trans-retinoic acid (RA)-treatment suppresses BZR-T33 proliferation in monolayer cultures and in anchorage independent and cloning efficiency growth assays. RA induces RAR-gamma 2 > RAR gamma 1 in BZR-T33 cells but expression at the total cellular RNA level of RAR alpha and RXR alpha is not augmented by RA-treatment. RAR beta mRNA expression is repressed before and after RA-treatment and is only detected using a reverse transcription polymerase chain reaction (RT-PCR) assay. To determine directly which of these expressed retinoid receptors signals growth suppression, each receptor was individually transfected into BZR-T33 cells using episomal vector in colony efficiency assays. RAR gamma over-expression in the presence or absence of RA-treatment did not suppress BZR-T33 growth more than controls. In contrast, over-expression of the other examined retinoid receptors inhibited BZR-T33 cellular cloning efficiency prior to RA-treatment and in this decreasing order after RA-treatment: RAR alpha > RAR beta > RXR alpha. The findings reported here reveal that RA suppresses proliferation and cloning efficiency in this transformed human bronchial epithelial cell through specific retinoid receptors. Further work is needed to evaluate the role of RA or its nuclear receptors in inhibiting even earlier steps in lung carcinogenesis.