Immunohistochemical study of thyroid transcription factor-1 and HER2/neu in non-small cell lung cancer: strong thyroid transcription factor-1 expression predicts better survival

Use of thyroid transcription factor 1 and napsin A to predict local failure and survival after Gamma Knife radiosurgery in patients with brain metastases from lung adenocarcinoma

OBJECTIVE

Stereotactic radiosurgery (SRS), combined with contemporary targeted therapies and immunotherapies, has improved the overall survival of patients with lung adenocarcinoma (ADC). Given that histological subtypes reflect prognosis in patients with primary ADC, it is important to integrate pathological biomarkers to predict clinical outcomes after SRS in patients with brain metastases from lung ADC. Therefore, the authors investigated the prognostic relevance of various biomarkers of primary lung ADC for clinical outcomes after SRS.

METHODS

A total of 95 patients with 136 brain metastases (1-4 oligometastases) who were treated with Gamma Knife radiosurgery between January 2017 and December 2020 were included. The Kaplan-Meier method and univariate and multivariate analyses using Cox proportional hazard regression models were used to identify prognostic factors for local control, survival, and distant brain control.

RESULTS

Multivariate analysis revealed thyroid transcription factor 1 as an independent prognostic factor for local control (HR 0.098, 95% CI 0.014-0.698, p = 0.0203) and napsin A as a significant predictor of overall survival after SRS (HR 0.080, 95% CI 0.017-0.386, p < 0.01). In a subset analysis of epidermal growth factor receptor (EGFR) mutation, patients with EGFR exon 19 mutations showed better distant brain control than those with EGFR exon 21 mutations (p < 0.01).

CONCLUSIONS

Pathological biomarkers of primary cancer should be considered to predict clinical outcomes after SRS in patients with lung ADC. Use of such biomarkers may help to provide personalized treatment to each patient, improving clinical outcomes after SRS.

Predicting Deep Learning Based Multi-Omics Parallel Integration Survival Subtypes in Lung Cancer Using Reverse Phase Protein Array Data

Mortality attributed to lung cancer accounts for a large fraction of cancer deaths worldwide. With increasing mortality figures, the accurate prediction of prognosis has become essential. In recent years, multi-omics analysis has emerged as a useful survival prediction tool. However, the methodology relevant to multi-omics analysis has not yet been fully established and further improvements are required for clinical applications. In this study, we developed a novel method to accurately predict the survival of patients with lung cancer using multi-omics data. With unsupervised learning techniques, survival-associated subtypes in non-small cell lung cancer were first detected using the multi-omics datasets from six categories in The Cancer Genome Atlas (TCGA). The new subtypes, referred to as integration survival subtypes, clearly divided patients into longer and shorter-surviving groups (log-rank test: p = 0.003) and we confirmed that this is independent of histopathological classification (Chi-square test of independence: p = 0.94). Next, an attempt was made to detect the integration survival subtypes using only one categorical dataset. Our machine learning model that was only trained on the reverse phase protein array (RPPA) could accurately predict the integration survival subtypes (AUC = 0.99). The predicted subtypes could also distinguish between high and low risk patients (log-rank test: p = 0.012). Overall, this study explores novel potentials of multi-omics analysis to accurately predict the prognosis of patients with lung cancer.

Thyroid transcription factor 1 and p63 expression is associated with survival outcome in patients with non-small cell lung cancer treated with erlotinib

While erlotinib is primarily administered to patients with non-small cell lung cancer with sensitizing epidermal growth factor receptor (EGFR) mutations, it is also prescribed to patients with wild type (wt) EGFR in higher lines of treatment. However, there is no predictive marker for erlotinib efficacy in patients with EGFR wt. Certain immunohistochemical (IHC) parameters, including thyroid transcription factor 1 (TTF1) and p63, have been reported to indicate predictive power in patients with EGFR wt. The present study focused on retrospective data from the University Hospital in Pilsen using the TULUNG register. TTF1 and p63 expression data were extracted from the hospital information system and merged with registry data to calculate progression-free survival (PFS) and overall survival (OS) rates. A cohort of 345 patients with adenocarcinoma (ADC) or squamous cell carcinoma (SCC) exhibited similar erlotinib efficacies when TTF1 and p63 were ignored. However, significant differences were reported in PFS and OS rates of a subgroup of 126 patients where TTF1 and p63 parameters were known. In a univariate analysis, group A (ADC TTF1+/p63-) achieved PFS of 2.6 months, group B (SSC TTF1-/p63+) 1.9 months and group C (did not fit into groups A or B, i.e., ADC TTF1-/p63+ or SCC TTF1+/p63-) 1.4 months (P=0.006). Median OS was 14.2, 19.1 and 5.3 months for A, B and C, respectively (P=0.002). Furthermore, a multivariate analysis demonstrated IHC markers to be the only significant parameters for PFS and OS. Group C had a negative prognostic factor for PFS [hazard ratio (HR), 1.812; P=0.02] and OS (HR=2.367; P=0.01). In conclusion, patients with EGFR wt and lung carcinomas without TTF1 and p63 expression typical for ADC (TTF1+/p633-) or SCC (TTF1-/p63+) do not appear to be suitable candidates for erlotinib treatment.

The prognostic effect of TTF-1 expression in the Chinese population of patients with advanced lung adenocarcinomas

Background

Thyroid transcription factor 1 (TTF-1), which is usually expressed by lung adenocarcinomas and small cell carcinomas, is usually used to distinguish adenocarcinoma and small cell carcinoma from cells of another type of lung cancer. We examined the association between TTF-1 expression and overall survival between patients with stage IV pulmonary adenocarcinoma to investigate the role of TTF-1 as a predictive and/or prognostic tumor marker in patients with advanced lung adenocarcinomas.

Methods

Analysis of the clinicopathologic features, treatment regimens, and overall survival of 209 lung adenocarcinoma patients who had been detected for TTF-1 expression and received consecutive treatments in the Affiliated Hospital of Qingdao University.

Results

TTF-1 expression was positive in 166 (79%) and negative in 43 (21%) patients who were reviewed. Moreover, there was no significant difference between the clinicopathologic features of TTF-1 positive and TTF-1 negative tumors. In the multivariable review, the overall survival of TTF-1 positive tumor patients was significantly longer than that of TTF-1 negative tumor patients [22.7 vs. 11.8 months (P<0.0001)], increasing the prognostic effect of Karnofsky performance status and receiving first-line chemotherapy or targeted therapy. Positive TTF-1 and negative TTF-1 patients receiving pemetrexed-based chemotherapy improved the duration of treatment compared to those receiving non-pemetrexed chemotherapy.

Conclusions

TTF-1 expression was associated with an improved survival in patients with advanced lung adenocarcinomas. Both patients, either TTF-1 positive or negative, could benefit from the first-line chemotherapy or pemetrexed treatment option. However, as discovered by our investigation, TTF-1 cannot forecast a portion of the lung adenocarcinomas that had a selective sensitivity to pemetrexed.

Prognostic Impact of TTF-1 Expression in Non-Squamous Non-Small-Cell Lung Cancer: A Meta-Analysis

Thyroid transcription factor-1 (TTF-1) is overexpressed in up to 95% of primary lung adenocarcinoma while negative for almost all squamous cell carcinomas. TTF-1 expression has been investigated as a prognostic factor in non-small-cell lung cancer (NSCLC) with conflicting results. We conducted this meta-analysis to gain a better insight into the prognostic role of TTF-1 in patients only with non-squamous (non-SQ) NSCLC. A systematic computerized search of the electronic databases including PubMed, PMC, EMBASE, Web of Science, and Cochrane Library was performed. From 21 studies, 6,451 patients were included in the combined analysis of hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival. Compared with patients with non-SQ NSCLC showing negative TTF-1 expression, those with tumors harboring TTF-1 overexpression had significantly better survival (HR = 0.49, 95% CI: 0.42-0.57, p < 0.00001). Subgroup analyses revealed that TTF-1 expression significantly correlated with a better prognosis in stage I (HR = 0.65, 95% CI: 0.50-0.84, p = 0.0008) as well as stage III-IV non-SQ NSCLC (HR = 0.38, 95% CI: 0.29-0.49, p < 0.00001). In conclusion, this meta-analysis demonstrates that TTF-1 overexpression is a favorable prognostic factor in patients with non-SQ NSCLC. The subgroup analyses indicate that TTF-1 is a good prognostic marker for survival not only in early-stage but also in advanced non-SQ NSCLC.

The Correlation between TTF-1 Immunoreactivity and the Occurrence of Lymph Node Metastases in Patients with Lung Cancer

Aims and background

Thyroid transcription factor (TTF-1) is a tissue-specific transcription factor expressed in the epithelial cells of thyroid and lung. The aim of this study was to evaluate the relationship between the expression of TTF-1 and clinicopathological parameters in pulmonary adenocarcinoma and adenosquamous carcinoma.

Methods

Resection material of pneumonectomies and lobectomies of 39 patients was retrospectively examined. Twenty-eight patients were diagnosed with adenocarcinoma and 11 with adenosquamous carcinoma. Tumors were classified into 3 groups: a strongly positive group (++) with ‡50% tumor cells positive for TTF-1; a weakly positive group (+) with 1–49% positive tumor cells; and a negative group (-) with less than 1% or no positive tumor cells. Analysis was performed with Kaplan-Meier estimates and log-rank tests.

Results

Staining for TTF-1 was negative in 10 cases. There was focal staining in 9 cases, while there was diffuse staining in 20 (51%) cases out of 39, and 15 (75%) of these were adenocarcinomas. There was a statistically significant association between TTF-1 and lymph node metastases (P = 0.029). No relationship was found between TTF-1 positivity and disease-free and overall survival.

Conclusions

TTF-1 expression may be a predictor of lymph node metastases. Additional work in a larger group of patients is needed to better assess the utility of this marker.

TTF-1- and/or CD56-positive Circulating Tumor Cells in patients with small cell lung cancer (SCLC)

The aim of the study was to evaluate the phenotypic CTCs heterogeneity (TTF-1⁺ and/or CD56⁺) in SCLC patients and correlate it with the CellSearch. Peripheral blood was obtained from 108 consecutive patients. CTCs were detected by CellSearch and double-immunofluorescence using anti-CD45, anti-TTF-1 and anti-CD56 antibodies. Before chemotherapy TTF-1⁺/CD45⁻, CD56⁺/CD45⁻ and TTF-1⁺/CD56⁺ CTCs were detected in 66(61.1%), 55(50.9%) and 46(42.6%) patients, respectively; 60.2% of patients were CellSearch⁺. Among the 22 patients with 0 CTCs/7.5 ml on CellSearch, TTF-1⁺/CD45⁻, CD56⁺/CD45⁻ and TTF-1⁺/CD56⁺ CTCs were detected in 8(36.4%), 6(27.3) and 6(27.3%) patients, respectively; no CK⁺/EpCAM⁺ or TTF1⁺/EpCAM⁺ CTCs were detected in these patients. One-chemotherapy cycle decreased both the number of positive patients (p < 0.001) and their CTC number (p < 0.001), irrespectively of their phenotype and the detection method. The incidence and number of the different CTC subpopulations on PD, was significantly increased at their baseline levels. Multivariate analysis revealed that the increased number of CTCs at baseline and on PD were significantly associated with decreased PFS (p = 0.048) and OS (p = 0.041), respectively. There is an important CTC heterogeneity in such patients according to the expression of TTF-1 and CD56 which could detect EpCAM⁻ CTC subpopulations and, thus, undetectable by CellSearch. These CTC subpopulations are dynamically correlated with treatment efficacy and disease-progression.

Thyroid transcription factor 1 expression is associated with outcome of patients with non-squamous non-small cell lung cancer treated with pemetrexed-based chemotherapy

Pemetrexed is an antifolate cytostatic agent targeting several folate-dependent enzymatic pathways, widely used in the treatment of locally advanced or metastatic stage non-small cell lung cancer. Aside from the non-squamous histology, there is still no available molecular biomarker predicting treatment efficacy of pemetrexed-based chemotherapy. The aim of our retrospective study was to evaluate the association of thyroid transcription factor 1 expression with outcome of a large cohort of patients with non-squamous non-small cell lung cancer treated with pemetrexed. We retrospectively analysed clinical data of 463 patients with advanced-stage non-small cell lung cancer (IIIB or IV) treated with pemetrexed-based chemotherapy. Thyroid transcription factor 1 expression was assessed using indirect immunohistochemical detection in formalin-fixed paraffin-embedded tumour tissue at the time of diagnosis. Thyroid transcription factor 1 expression was detected in the tumour tissue from 76.0% of patients, and tumours from 24.0% of patients were thyroid transcription factor 1 negative. The median progression-free survival and overall survival for patients with thyroid transcription factor 1 positive tumours were 4.8 and 11.8 months compared to 2.8 and 8.3 months for those with thyroid transcription factor 1 negative tumours (p = 0.001 and p < 0.001). The multivariable Cox proportional hazards model revealed that thyroid transcription factor 1 expression was significantly associated with progression-free survival (hazard ratio = 1.57, p < 0.001) and also with overall survival (hazard ratio = 1.73, p < 0.001). In conclusion, the results of the conducted retrospective study suggest that the thyroid transcription factor 1 expression was independently associated with progression-free survival and overall survival in patients with advanced-stage non-squamous non-small cell lung cancer treated with pemetrexed-based chemotherapy.

Negative Thyroid Transcription Factor 1 Expression Defines an Unfavorable Subgroup of Lung Adenocarcinomas

INTRODUCTION

Thyroid transcription factor 1 (TTF1) is a master regulator of pulmonary differentiation that is downregulated in a subset of lung adenocarcinoma, of which the clinicopathologic characteristics were not fully clarified.

METHODS

One thousand forty-two lung adenocarcinoma patients who underwent surgery were investigated for clinic characteristics, histologic subtyping, and spectrum of well-identified driver mutations. TTF1 expression was correlated with these clinicopathologic factors and survival.

RESULTS

Compared with TTF1 positive (TTF1+) patients, the 133 negative individuals (12.8%, TTF1-) were more likely to be male (p = 0.006) and heavy smokers (p = 0.002) who had larger tumor size (p < 0.001) and more advanced disease stage (p < 0.001). TTF1- presented more in solid and invasive mucinous-predominant carcinomas (both p < 0.001), whereas TTF1+ was identified in 100% patients with adenocarcinoma in situ, minimally invasive and lepidic-predominant adenocarcinomas. The TTF1- tumors harbored the known driver mutations in significantly low frequency compared with TTF1+ adenocarcinomas (57.8% versus 78.1%, p < 0.001), especially in epidermal growth factor receptor (EGFR) mutations (37.6% versus 60.7%, p < 0.001). There was no significant difference in recurrence-free survival between the TTF1- and TTF1+ patients, either for the whole cohort or stratified by pathologic stage, or among the driver mutation-defined subsets. However, recurrence of multiple metastases was more likely to occur in patients with TTF1- adenocarcinomas (88.1% versus 32.4%, p < 0.001). Multivariate analysis revealed that TTF1- independently predicted both poor postrecurrence survival (hazard ratio = 1.664; 95% confidence interval , 1.097-2.524; p = 0.017) and unfavorable overall survival (hazard ratio = 1.553; 95% confidence interval , 1.013-2.381; p = 0.043).

CONCLUSIONS

TTF1- correlated with solid and invasive mucinous subtypes of lung adenocarcinoma and lower frequency of EGFR mutations. It defines a subgroup of lung adenocarcinomas with unfavorable outcomes.

Value of thyroid transcription factor (TTF)-1 for diagnosis and prognosis of patients with locally advanced or metastatic small cell lung cancer

Background

The aim of this study was to analyze the frequency of Thyroid Transcription Factor (TTF)-1 expression in small cell lung cancer (SCLC) and its value for the diagnosis of SCLC, the response to first line treatment as well as the prognostic impact on overall survival (OS).

Methods

We analyzed a total of 294 patients (m, n = 184; f, n = 110) with SCLC (stage IIIA, n = 32; IIIB, n = 87; IV, n = 175) diagnosed in our institution between January 2005 and December 2008. Patient’s characteristics comprising age, gender, histology and first line treatment were included into the analyses. For the follow-up of patients the governmental death registrar was used. The TTF-1 immunostaining was prospectively performed. CT scans of all patients were reviewed and response to treatment was evaluated using the Response Evaluation Criteria In Solid Tumors 1.0 (RECIST) criteria.

Results

A total of 221 of the 294 patients were eligible for analysis. Patients with TTF-1-positive SCLC had a median OS of 374 (95% CI 306–442) days. The OS of patients with TTF1-negative SCLC was 290 (95% CI 191–389) days, which was not significantly shorter (p = 0.254). Also stratification for tumor stage did not reveal significant difference in OS. Analyzing the disease control rate (DCR) in patients with metastatic disease (stage IV), we observed a significantly (p = 0.006) improved response to treatment in the group of patients with TTF-1-expression (DCR 86% vs. 56%). Regarding the overall response rates (ORR) in the entire population, there was no difference observed between both subgroups. (TTF-1-pos. 75.3% vs. TTF-1-neg. 71.4%; p = 0.642).

Conclusions

The diagnostic information of TTF-1 in SCLC seems to be limited. TTF-1 had no prognostic value concerning OS, but may serve as a predictor for response to first line chemotherapy.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5811254651472285

Prognostic value of TTF-1 expression in patients with non-small cell lung cancer: A meta-analysis

BACKGROUND

Observational studies on the prognostic role of thyroid transcription factor 1 (TTF-1) in non-small-cell lung cancer (NSCLC) are controversial.

METHODS

To clarify the impact of TTF-1 in NSCLC survival, we performed this meta-analysis that included eligible studies. The combined hazard ratios and their corresponding 95% confidence intervals were calculated in terms of overall survival.

RESULTS

A total of 17 studies with 2235 patients were evaluable for this meta-analysis. The studies were categorized by histology, disease stage and patient race. Our results suggested that TTF-1 overexpression had a favorable impact on survival of patients with NSCLC, the HR (95% CI) was 0.49 (0.42 to 0.55) overall, 0.46 (0.38-0.54) in Asian patients, 0.52 (0.42-0.63) in non-Asian patients, 0.45 (0.38-0.52) in adenocarcinoma, 0.63 (0.39-0.86) in stage I NSCLC, and 0.43 (0.33-0.53) in stage IIIb-IV NSCLC. The data collected were not sufficient to determine the prognostic value of VEGF in patients with squamous cell lung carcinomas. But there was a high heterogeneity between the studies.

CONCLUSION

TTF-1 overexpression indicates a favorable prognosis for patients with NSCLC, this effect appears also significant when the analysis is restricted in lung AC patients, stage I and stage IIIb-IV NSCLC.

Value of thyroid transcription factor-1 immunostaining in tumor diagnosis: a review and update

Thyroid transcription factor-1 (TTF-1) is a tissue-specific transcription factor that plays a critical role in the normal development of embryonic epithelial cells of the thyroid and lung. Because TTF-1 expression is highly restricted to epithelial tumors arising in these organs, it is, at present, one of the immunohistochemical markers most commonly used to assist in the differential diagnosis of carcinomas of the lung and thyroid. Recent studies, however, have reported that TTF-1 is not as specific for lung and thyroid carcinomas as was previously thought as it can be found to be expressed, although much less frequently, in some carcinomas arising in other organs, such as the ovaries, endometrium, colon, and breast, as well as in some tumors of the central nervous system. Even though this unexpected TTF-1 positivity has been reported more frequently with the recently available SPT24 anti-TTF-1 monoclonal antibody, it has also been shown to occur with the commonly used 8G7G3/1 clone, albeit in a lower percentage of cases. Despite these findings, TTF-1 remains a very useful immunohistochemical marker in diagnostic pathology.

Nkx2-1: a novel tumor biomarker of lung cancer

Nkx2-1 (Nkx homeobox-1 gene), also known as TTF-1 (thyroid transcription factor-1), is a tissue-specific transcription factor of the thyroid, lung, and ventral forebrain. While it has been shown to play a critical role in lung development and lung cancer differentiation and morphogenesis, molecular mechanisms mediating Nkx2-1 cell- and tissue-specific expression in normal and cancerous lungs have yet to be fully elucidated. The recent identification of prognostic biomarkers in lung cancer, particularly in lung adenocarcinoma (ADC), and the different reactivity of patients to chemotherapeutic drugs have opened new avenues for evaluating patient survival and the development of novel effective therapeutic strategies. The function of Nkx2-1 as a proto-oncogene was recently characterized and the gene is implicated as a contributory factor in lung cancer development. In this review, we summarize the role of this transcription factor in the development, diagnosis, and prognosis of lung cancer in the hope of providing insights into the utility of Nkx2-1 as a novel biomarker of lung cancer.

Thyroid transcription factor-1 expression is an independent predictor of recurrence and correlates with the IASLC/ATS/ERS histologic classification in patients with stage I lung adenocarcinoma

BACKGROUND

In the current study, the authors investigated whether thyroid transcription factor-1 (TTF-1) expression is correlated with the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification and whether it stratifies patients with stage I lung adenocarcinoma with respect to disease recurrence.

METHODS

Patients with stage I lung adenocarcinoma were classified according to the IASLC/ATS/ERS classification. Tissue microarrays were constructed and immunostaining for TTF-1 was performed. A total of 452 cases were available for analysis. Tumors were dichotomized based on the intensity of nuclear TTF-1 expression as negative (score of 0) or positive (score of 1-3). The cumulative incidence of recurrence (CIR) was used to estimate disease recurrence probabilities.

RESULTS

TTF-1 expression was identified in 92% of patients, including 100% of patients with minimally invasive or lepidic-predominant adenocarcinoma, 94% of patients with acinar-predominant adenocarcinoma, 98% of patients with papillary-predominant adenocarcinoma, 93% of patients with micropapillary-predominant adenocarcinoma, 86% of patients with solid-predominant adenocarcinoma, 67% of patients with colloid-predominant adenocarcinoma, and 47% of patients with invasive mucinous carcinoma. The CIR for patients with negative TTF-1 expression (n = 34 patients; 5-year CIR, 40%) was significantly higher than that for patients with positive TTF-1 expression (n = 418 patients; 5-year CIR, 15%) (P < .001). Among the patients with intermediate-grade tumors, the CIR for patients with negative TTF-1 expression (n = 16 patients; 5-year CIR, 45%) was significantly higher than that for patients with positive TTF-1 expression (n = 313 patients; 5-year CIR, 14%) (P < .001). On multivariate analysis, negative TTF-1 expression was found to be significantly correlated with an increased risk of disease recurrence (hazards ratio, 2.55; P = .009).

CONCLUSIONS

TTF-1 expression was found to be an independent predictor of disease recurrence, stratifying intermediate-grade tumors into 2 prognostic subsets, and it correlates with the IASLC/ATS/ERS classification.

Napsin A expression in lung and kidney neoplasia: a review and update

Napsin A is an aspartic protease present in the epithelial cells of the lung and kidney. Recent studies have shown that, in lung tumors, napsin A expression is restricted to lung adenocarcinomas, whereas among renal tumors, it is frequently expressed in renal cell carcinomas, especially the papillary and clear cell subtypes. Owing to its restricted expression, napsin A is a useful marker that can assist in the diagnosis of both lung adenocarcinomas and renal cell carcinomas.

Expression of thyroid transcription factor-1 in colorectal carcinoma

Thyroid transcription factor-1 (TTF-1) is a member of the homeodomain transcription family expressed in epithelial cells of the thyroid and lung. Although nuclear TTF-1 is generally considered a specific marker for lung and thyroid neoplasms, it has been reported to be positive in other types of tumors including colorectal carcinoma (CRC). During metastatic adenocarcinoma workup for patients who had a history of CRC, we identified 4 positive TTF-1 cases using clone 8G7G3/1. Three of the 4 corresponding primary carcinomas were also positive for TTF-1. Therefore, we sought to retrospectively investigate the expression of TTF-1 in 100 CRC cases constructed in tissue microarray blocks and whole tissue sections of the 4 primary tumors corresponding to the 4 positive metastases. In tissue microarray cases, all cases had negative nuclear staining. Our results suggest that during immunohistochemical workup for adenocarcinoma, especially when the differential diagnosis includes the lung and CRC, TTF-1 results should be interpreted with caution as a small percentage of CRC expresses this marker. Positive nuclear TTF-1 in a metastatic carcinoma does not rule out CRC primary. Clinicopathologic correlation, tumor morphology, and a panel of immunohistochemical markers are essential to render the correct diagnosis.

Clinical significance of TTF-1 protein expression and TTF-1 gene amplification in lung adenocarcinoma

The majority of lung adenocarcinomas express the lineage-specific thyroid transcription factor-1 (TTF-1). We recently reported that in a subset of lung adenocarcinomas the TTF-1 gene is amplified. Although the prognostic significance of TTF-1 expression has been previously investigated, the significance of TTF-1 amplification has not been established. We studied 89 consecutive patients with lung adenocarcinomas treated by surgery at Brigham and Women's Hospital between 1997 and 1999 and performed immunohistochemical analysis for TTF-1 expression and fluorescence in situ hybridization for TTF-1 amplification. We investigated associations between clinical-pathological characteristics, TTF-1 expression, TTF-1 amplification and overall survival. TTF-1 expression was categorized as high (48%), low (24%) or absent (28%). TTF-1 was amplified in 7% of cases. Patients with adenocarcinomas with low or high TTF-1 expression had a significantly better outcome than those with absent TTF-1 expression (median overall survival times of 72.4, 77.8 and 30.5 months, respectively, P = 0.002). In contrast, patients with adenocarcinomas with TTF-1 expression had a worse outcome if TTF-1 was amplified (median overall survival time 39.5 versus 87.5 months). In multivariate analysis, improved overall survival was independently predicted by TTF-1 expression in combination with no TTF-1 amplification (P < 0.001). In patients with lung adenocarcinoma, TTF-1 expression is a predictor of good outcome. Patients with no TTF-1 expression or TTF-1 expression and TTF-1 gene amplification tend to have a significantly worse prognosis than patients with TTF-1 expression and no TTF-1 gene amplification.

Thyroid transcription factor-1 immunohistochemistry: diagnostic tool and malignancy marker in canine malignant lung tumours

Distinguishing primary lung carcinomas (PLCs) from metastases is a challenging task. The diagnostic and prognostic relevance of thyroid transcription factor-1 (TTF-1), a nuclear protein expressed in follicular cells of the thyroid gland and pneumocytes, was tested in 34 primary and 27 nonprimary canine lung tumours. Normal pneumocytes stained negatively in 14 PLCs because of overfixation or prolonged storage of paraffin blocks and were excluded from the study. Among the 20 immunoreactive PLCs, 17 showed strong nuclear positivity. The three tumours that scored negative were two squamous cell and one papillary carcinoma. Metastatic tumours were always negative. TTF-1 was 100% specific and 85% sensitive for PLCs. There was no significant relationship among the percentage of labelled tumour cells (TTF-1 index) and the considered clinicopathological parameters (age, gender, histological type, tumour grade, TNM stage, node status and MIB-1 index). TTF-1 immunohistochemistry may give useful additional information regarding the origin of canine lung tumours, whereas its prognostic use still needs to be determined.

Expression of secretoglobin3A2 (SCGB3A2) in primary pulmonary carcinomas

Secretoglobin (SCGB) 3A2 is a downstream target gene for the thyroid transcription factor-1 (TITF1). SCGB3A2 plays a role as an anti-inflammatory agent, however, its role in primary pulmonary carcinomas has not been examined. We assessed immunohistochemical expression of SCGB3A2 in primary pulmonary carcinomas and evaluated the correlation between the expression and histopathological phenotypes and prognosis. One hundred and fifty-six primary lung cancers undergone for surgical resection were examined. The percentages of SCGB3A2 positive cells were scored and tumors had immunoreactivity in more than 10% of tumor cells were considered positive for SCGB3A2. Overall reactivity for SCGB3A2 was observed in 116 (74.4%) of 156 primary lung cancers. SCGB3A2 was predominantly expressed in adenocarcinomas (86.5%), compared with squamous cell carcinomas (50.0%) and small cell carcinomas (42.9%). The expression in papillary adenocarcinomas was seen at higher frequency than that in tubular adenocarcinomas. There was no significant relationship between SCGB3A2 expression and tumor differentiation, and pathological stage. Positive expression of SCGB3A2 was not associated with better survival rate. SCGB3A2 expression in primary pulmonary carcinomas is high, especially in adenocarcinomas. Our results indicate that SCGB3A2 has a potential to be a specific and useful marker for primary pulmonary adenocarcinomas.

Characterizing the developmental pathways TTF-1, NKX2-8, and PAX9 in lung cancer

We investigated the clinical implications of lung developmental transcription factors (TTF-1, NKX2-8, and PAX9) that we recently discovered as cooperating oncogenes activated by way of gene amplification at chromosome 14q13 in lung cancer. Using stable transfectants of human bronchial epithelial cells, RNA expression profiles (signatures) representing activation of the biological pathways defined by each of the 3 genes were determined and used to risk stratify a non-small-cell lung cancer (NSCLC) clinical data set consisting of 91 early stage tumors. Coactivation of the TTF-1 and NKX2-8 pathways identified a cluster of patients with poor survival, representing approximately 20% of patients with early stage NSCLC, whereas activation of individual pathways did not reveal significant prognostic power. Importantly, the poor prognosis associated with coactivation of TTF-1 and NKX2-8 was validated in 2 other independent clinical data sets. Furthermore, lung cancer cell lines showing coactivation of the TTF-1 and NKX2-8 pathways were shown to exhibit resistance to cisplatin, the standard of care for the treatment of NSCLC. This suggests that the cohort of patients with coactivation of TTF-1 and NKX2-8 pathways appears to be resistant to standard cisplatin therapy, suggesting the need for alternative therapies in this cohort of high-risk patients.

Thyroid transcription factor-1 (TTF-1/Nkx2.1/TITF1) gene regulation in the lung

TTF-1 [thyroid transcription factor-1; also known as Nkx2.1, T/EBP (thyroid-specific-enhancer-binding protein) or TITF1] is a homeodomain-containing transcription factor essential for the morphogenesis and differentiation of the thyroid, lung and ventral forebrain. TTF-1 controls the expression of select genes in the thyroid, lung and the central nervous system. In the lung, TTF-1 controls the expression of surfactant proteins that are essential for lung stability and lung host defence. Human TTF-1 is encoded by a single gene located on chromosome 14 and is organized into two/three exons and one/two introns. Multiple transcription start sites and alternative splicing produce mRNAs with heterogeneity at the 5' end. The 3' end of the TTF-1 mRNA is characterized by a rather long untranslated region. The amino acid sequences of TTF-1 from human, rat, mouse and other species are very similar, indicating a high degree of sequence conservation. TTF-1 promoter activity is maintained by the combinatorial or co-operative actions of HNF-3 [hepatocyte nuclear factor-3; also known as FOXA (forkhead box A)], Sp (specificity protein) 1, Sp3, GATA-6 and HOXB3 (homeobox B3) transcription factors. There is limited information on the regulation of TTF-1 gene expression by hormones, cytokines and other biological agents. Glucocorticoids, cAMP and TGF-beta (transforming growth factor-beta) have stimulatory effects on TTF-1 expression, whereas TNF-alpha (tumour necrosis factor-alpha) and ceramide have inhibitory effects on TTF-1 DNA-binding activity in lung cells. Haplo-insufficiency of TTF-1 in humans causes hypothyroidism, respiratory dysfunction and recurring pulmonary infections, underlining the importance of optimal TTF-1 levels for the maintenance of thyroid and lung function. Recent studies have implicated TTF-1 as a lineage-specific proto-oncogene for lung cancer.

Thyroid transcription factor 1 is an independent prognostic factor for patients with stage I lung adenocarcinoma

PURPOSE

Thyroid transcription factor 1 (TTF1) is a transcription factor that regulates the expression of multiple genes involved in lung development. It is preferentially expressed in adenocarcinomas of the lung and has been investigated as a potential prognostic parameter in patients with lung cancer, with conflicting results. We quantitatively assessed TTF1 protein expression in two large and independent data sets to investigate the impact of TTF1 nuclear expression on patient survival.

PATIENTS AND METHODS

Automated quantitative analysis, a fluorescent-based method for analysis of in situ protein expression, was used to assess a series of cell lines to find the threshold of detection of TTF1 expression. Then two independent cohorts (176 and 237 cases, respectively) were measured by the same technique, and TTF1 expression was correlated with survival.

RESULTS

Tumors expressed TTF1 in 45% and 58% of the cases in each cohort. TTF1 was consistently expressed in adenocarcinomas (n = 61 and 73; Spearman rho = 0.313 and 0.4 for the first and second set, respectively; P < .0001) independent of their differentiation and stage. Survival analysis showed that patients with stage I adenocarcinoma with TTF1 expression had a longer median overall survival than those without expression (n = 43, 44.3 v 26.2 months, P = .05 for the first cohort; n = 87; 49.7 v 38.5 months, P = .03 for the second cohort) Multivariate analysis revealed an independent lower risk of death for patients with stage I adenocarcinoma with TTF1-expressing tumors (hazard ratio = 0.479, 95% CI, 0.235 to 0.977; P = .043).

CONCLUSION

TTF1 expression defines a subgroup of patients with a favorable outcome and may be useful for prognostic stratification of patients with stage I lung adenocarcinoma.

Small cell carcinoma of the urinary bladder--histogenesis, genetics, diagnosis, biomarkers, treatment, and prognosis

Small cell carcinoma of the urinary bladder is a rare but highly aggressive malignancy with a dismal prognosis. Most patients present with advanced disease at the time of diagnosis. Hematuria is the most frequent presenting symptom. Histologically, small cell carcinoma of the urinary bladder is indistinguishable from its pulmonary counterpart. Coexistence with other types of carcinoma is common. Histogenesis is uncertain; there are several competing theories, including origin from stem cells, from urothelial cells, and from neuroendocrine cells in normal or metaplastic urothelium. The molecular pathogenesis remains unclear. Immunohistochemical staining can be extremely helpful in establishing the diagnosis, and in investigating the use of potential therapeutic strategies. Currently, combinations of surgical resection, chemotherapy, and radiation therapy represent the main treatment options. The recent observation of c-kit and epidermal growth factor receptor expression in more than 25% of patients with urinary bladder small cell carcinoma opens new avenues for further investigation. Improvement in survival may depend upon the identification of new molecular markers to facilitate earlier diagnosis and the development of novel targeted therapies. In this paper, we review general aspects of small cell carcinoma of the urinary bladder, focusing on the ways in which our understanding of this entity has been positively influenced by studies of the histopathologic and immunohistochemical findings, and by investigations of genetic alterations in this disease.

Thyroid transcription factor 1--a new prognostic factor in lung cancer: a meta-analysis

BACKGROUND

The aim of this study was to determine the prognostic role for survival of thyroid transcription factor 1 (TTF-1) in lung cancer.

METHODS

Studies evaluating survival and TTF-1 in lung cancer patients, published until August 2005, were assessed with a methodological scoring system. The required data for estimation of individual hazard ratios (HRs) for survival were extracted from the publications and a combined HR was calculated.

RESULTS

We identified 10 eligible papers, all dealing with non-small-cell lung cancer (NSCLC). Eight were meta-analysed (evaluable studies). Seven studies included patients with local and/or locoregional diseases and three dealt only with adenocarcinoma. Median methodological quality score was 65.9% (range = 31.8%-70.5%). TTF-1 positivity was associated with statistically significant reduced or improved survival in one and four studies, respectively. Combined HR for the eight evaluable studies was 0.64 [95% confidence interval (CI) = 0.41-1.00]. In the subgroup of adenocarcinoma, the combined HR was 0.53 (95% CI = 0.29-0.95).

CONCLUSION

TTF-1 is a good prognostic factor for survival in NSCLC. Its effect appears also significant when the analysis is restricted to patients with adenocarcinoma. This study supports the fact that TTF-1 could be included in further prospective trials studying prognostic factors in NSCLC.

Positive thyroid transcription factor 1 staining strongly correlates with survival of patients with adenocarcinoma of the lung

This study investigated the relation between positive thyroid transcription factor 1 (TTF1) staining and survival of patients affected by primary adenocarcinoma (ADC) of the lung. Pathological tissue from consecutive ADC patients was collected from 2002 to 2004. The anti-TTF1 antibody (8G7G3/1, dilution of 1/200) was used. Thyroid transcription factor 1 staining was assessed for each tumour as positive or negative. Probability of survival was estimated by Kaplan–Meier and difference tested by log-rank test. A Cox's regression multivariate analysis was carried out. In all, 106 patients were studied (66% male, 69% PS0–1, 83% with stage III or IV). Tumours expressed positive TTF1 staining in 66% of cases. Multivariate analysis demonstrated an independent lower risk of death for patients whose tumour expresses positive TTF1 staining (HR=0.51, 95% CI 0.30–0.85; P=0.01) and higher grade of differentiation (HR=0.40, 95% CI 0.24–0.68; P=0.001). In conclusion, positive TTF1 staining strongly and independently correlates with survival of patients with primary ADC of the lung.

Thyroid transcription factor 1 in pulmonary adenocarcinoma

AIMS

To discover whether variations in thyroid transcription factor 1 (TTF-1) staining in different subtypes and patterns of pulmonary adenocarcinoma are related to the putative origin of the tumour. In addition, to confirm the specificity of TTF-1 for pulmonary (as opposed to other sites) adenocarcinoma, to examine the possible prognostic relevance of TTF-1 positivity in lung cancer, and to review this laboratory's experience of TTF-1 in diagnostic practice.

MATERIALS/METHODS

In total, 128 primary lung adenocarcinomas, 106 primary non-pulmonary adenocarcinomas, and 37 pulmonary non-adenocarcinoma tumours were studied. In addition, 100 cases where TTF-1 was used in routine surgical pathology practice were investigated. Immunoperoxidase staining was performed on formalin fixed, paraffin wax embedded sections using anti-TTF-1 antibody. Staining was evaluated semiquantitatively using the frequency and intensity of nuclear positivity.

RESULTS

None of the 106 non-pulmonary adenocarcinomas expressed TTF-1 and only three of the 37 non-adenocarcinoma lung cancers, all neuroendocrine carcinomas, were positive. Of the pulmonary adenocarcinomas, 75% were strongly positive for TTF-1. Mucinous (two of six) and poorly differentiated adenocarcinomas (four of 10) were less likely to stain. Of the peripheral adenocarcinomas, 33 of 37 were positive, whereas only seven of 14 of those of bronchial origin stained strongly. Atypical adenomatous hyperplasia strongly expressed TTF-1. No "false positives" were encountered in the 100 routine diagnostic cases.

CONCLUSION

Positive TTF-1 staining is useful in the differential diagnosis of pulmonary adenocarcinomas. TTF-1 may be a lineage marker for tumours arising from the peripheral airway or alveolar epithelium and has no prognostic relevance.