A Phase II Study of Neoadjuvant Chemoradiotherapy with Docetaxel, Cisplatin and 5-FU Followed by Surgical Resection in the Treatment of Locally Advanced Esophagogastric Junction Cancer and Locally Advanced Esophageal Cancer

PURPOSE

We conducted a phase II study evaluating chemoradiotherapy in patients with advanced esophageal cancer, using the docetaxel, cisplatin, and 5-fluorouracil (DCF) regimen followed by surgery. The primary purposes of this clinical trial were to assess the efficacy and safety of chemoradiotherapy employing the DCF regimen in the treatment of advanced esophageal cancer.

MATERIAL AND METHODS

We enrolled a total of 24 newly diagnosed esophageal cancer patients between April 2015 and November 2017 in this prospective study. The radiotherapy regimen consisted of a total dose of 45 Gy in 25 fractions. The chemotherapy protocol included docetaxel 35 mg/m2 for 1 h on day 1 and day 29, cisplatin 35 mg/m2 for 1 h on day 1 and day 29, and 5-FU 400 mg/m2 for 24 h on day 1-4 and day 29-32. The patients who accepted the re-staging exam should undergo surgery in 4-8 weeks after the completion of radiotherapy. The primary endpoints of this study were disease-free survival (DFS), overall survival (OS), and the evaluation of hematologic toxicity.

RESULTS

The study population had a median age of 55.5 years, ranging from 44 to 66, with over 90% of the patients being male. The 5-year DFS was 37.1%, and the 5-year OS was 48.7%. The pathologic complete response rate was 45.8% (11/24). The most common types of toxicity were leukopenia and thrombocytopenia. No grade 3 or greater hematologic toxicity was reported.

CONCLUSIONS

The use of the DCF regimen in neoadjuvant chemoradiotherapy followed by surgery demonstrated tolerable toxicity and achieved acceptable DFS and OS outcomes.

Low-Dose Computed Tomography Screening in Relatives With a Family History of Lung Cancer

INTRODUCTION

The role of a family history of lung cancer (LCFH) in screening using low-dose computed tomography (LDCT) has not been prospectively investigated with long-term follow-up.

METHODS

A multicenter prospective study with up to three rounds of annual LDCT screening was conducted to determine the detection rate of lung cancer (LC) in asymptomatic first- or second-degree relatives of LCFH.

RESULTS

From 2007 to 2011, there were 1102 participants enrolled, including 805 and 297 from simplex and multiplex families (MFs), respectively (54.2% women and 70.0% never-smokers). The last follow-up date was May 5, 2021. The overall LC detection rate was 4.5% (50 of 1102). The detection rate in MF was 9.4% (19 of 202) and 4.4% (4 of 91) in never-smokers and in those who smoked, respectively. The corresponding rates for simplex families were 3.7% (21 of 569) and 2.7% (6 of 223), respectively. Of these, 68.0% and 22.0% of cases with stage I and IV diseases, respectively. LC diagnoses within a 3-year interval from the initial screening tend to be younger, have a higher detection rate, and have stage I disease; thereafter, more stage III-IV disease and 66.7% (16 of 24) with negative or semipositive nodules in initial computed tomography scans. Within the 6-year interval, only maternal (modified rate ratio = 4.46, 95% confidence interval: 2.32-8.56) or maternal relative history of LC (modified rate ratio = 5.41, 95% confidence interval: 2.84-10.30) increased the risk of LC.

CONCLUSIONS

LCFH is a risk factor for LC and is increased with MF history, among never-smokers, younger adults, and those with maternal relatives with LC. Randomized controlled trials are needed to confirm the mortality benefit of LDCT screening in those with LCFH.

Whole exome sequencing and MicroRNA profiling of lung adenocarcinoma identified risk prediction features for tumors at stage I and its substages

OBJECTIVES

About 20% of stage I lung adenocarcinoma (LUAD) patients suffer a relapse after surgical resection. While finer substages have been defined and refined in the AJCC staging system, clinical investigations on the tumor molecular landscape are lacking.

MATERIALS AND METHODS

We performed whole exome sequencing, DNA copy number and microRNA profiling on paired tumor-normal samples from a cohort of 113 treatment-naïve stage I Taiwanese LUAD patients. We searched for molecular features associated with relapse-free survival (RFS) of stage I or its substages and validated the findings with an independent Caucasian LUAD cohort.

RESULTS

We found sixteen nonsynonymous mutations harbored at EGFR, KRAS, TP53, CTNNB1 and six other genes associated with poor RFS in a dose-dependent manner via variant allele fraction (VAF). An index, maxVAF, was constructed to quantify the overall mutation load from genes other than EGFR. High maxVAF scores discriminated a small group of high-risk LUAD at stage I (median RFS: 4.5 versus 69.5 months; HR = 10.5, 95% CI = 4.22-26.12, P < 0.001). At the substage level, higher risk was found for patients with high maxVAF or high miR-31; IA (median RFS: 32.1 versus 122.8 months, P = 0.005) and IB (median RFS: 7.1 versus 26.2, P = 0.049). MicroRNAs, miR-182, miR-183 and miR-196a were found correlated with EGFR mutation and poor RFS in stage IB patients.

CONCLUSION

Distinctive features of somatic gene mutation and microRNA expression of stage I LUAD are characterized to complement the survival prognosis by substaging. The findings open up more options for precision management of stage I LUAD patients.

Experiences in reverse sequence esophagectomy: a promising alternative for esophageal cancer surgery

OBJECTIVES

McKeown esophagectomy is a standard and significant component of multimodality therapy in esophageal cancer, however, experience in switching the resection and reconstruction sequence in esophageal cancer surgery is not available. Here, we have retrospectively reviewed the experience of reverse sequencing procedure at our institute.

METHODS

We retrospectively reviewed 192 patients who had undergone minimally invasive esophagectomy (MIE) with McKeown esophagectomy between August 2008 and Dec 2015. The patient's demographics and relevant variables were evaluated. The overall survival (OS) and disease-free survival (DFS) were analyzed.

RESULTS

Among the 192 patients, 119 (61.98%) received the reverse sequence MIE (the reverse group) and 73 patients (38.02%) received the standard operation (the standard group). Both patient groups had similar demographics. There were no inter-group differences existed in blood loss, hospital stay, conversion rate, resection margin status, operative complication, and mortality. The reverse group had shorter total operation time (469.83 ± 75.03 vs 523.63 ± 71.93, p < 0.001) and thoracic operation time (181.22 ± 42.79 vs 230.41 ± 51.93, p < 0.001). The 5-year OS and DFS for both groups were similar (44.77% and 40.53% in the reverse group vs 32.66% and 29.42% in the standard group, p = 0.252 and 0.261, respectively). Similar results were observed even after propensity matching.

CONCLUSIONS

The reverse sequence procedure had shorter operation times, especially in the thoracic phase. The reverse sequence MIE is a safe and useful procedure when postoperative morbidity, mortality, and oncological outcomes are considered.

AGR2 expression as a predictive biomarker for therapy response in esophageal squamous cell carcinoma

Despite multidisciplinary therapy, the prognosis is poor for esophageal squamous cell carcinoma (ESCC). In the locally advanced stage, neoadjuvant chemoradiotherapy (nCRT) followed by surgery could provide survival benefits to some patients. Here, we aimed to identify for tumor therapy response a biomarker based on RNA sequencing. We collected endoscopic biopsies of 32 ESCC patients, who were divided according to nCRT response, into two groups: the complete response group (n  =  13) and the non-complete response group (n  =  19). RNA-sequencing data showed that 464 genes were differentially expressed. Increased in non-complete response group, 4 genes increased expressions were AGR2 (anterior gradient 2), GADD45B (growth arrest and DNA damage inducible beta), PPP1R15A (protein phosphatase 1 regulatory subunit 15A) and LRG1 (leucine rich alpha-2-glycoprotein 1). The areas under the curve (AUC) of the AGR2 gene was 0.671 according to read counts of RNA-seq and therapy response of nCRT. In vitro study showed that apoptosis cell was significantly increased in the AGR2-knockdown TE-2 cell line treated with cisplatin and 5-Fluorouracil (5-FU), when compared with si-control. Results suggest that in ESCC, the AGR2 gene is a promising and predictive gene marker for the response to anti-tumor therapy.

Surgery or Surveillance for Esophageal Squamous Cell Carcinoma With Clinical Complete Response After Neoadjuvant Chemoradiotherapy

We aimed to evaluate the role of esophagectomy in patients with esophageal squamous cell carcinoma with clinically complete response (cCR) after neoadjuvant chemoradiotherapy. Data of patients with locally advanced esophageal squamous cell carcinoma who achieved cCR after neoadjuvant chemoradiotherapy between October 2008 and September 2018 were retrospectively reviewed. The criteria for cCR include: (1) tumor resolution on computed tomography, (2) maximum standardized uptake value decrement >35% on positron-emission tomography-computed tomography scan, and (3) a negative endoscopic biopsy result. Overall survival (OS) and disease-free survival (DFS) were compared between patients who received surveillance only (surveillance) and those who underwent surgery. A total of 154 patients with cCR, including 54 in the surveillance group and 100 in the surgery group, were included. The 5-year OS rates in the surveillance and surgery groups were 47.9% and 36.9 %, respectively (P= 0.210). The 5-year DFS rates were 38.1% and 28.2%, respectively (P = 0.203). Surgery was not a prognostic factor in the multivariable analysis (OS: HR: 1.26, 95% CI: 0.69-2.33, P = 0.453; DFS: HR: 1.08, 95% CI: 0.60-1.96, P = 0.795). In the surgery group, ypT0N0, ypT+Nany, and ypT0N+ were noted in 54%, 37%, and 9% of patients, respectively. The 5-year OS rates were 55.8%, 22.2%, and 12.4%, respectively (P = 0.001). No survival differences were noted between the surveillance and surgery groups. However, 46% of cCR patients in the surgery group did not have pathological complete response, and their outcomes were poor. Esophagectomy may be the only way to identify patients with residual disease.

Lymphovascular Invasion as the Major Prognostic Factor in Node-Negative Esophageal Cancer After Primary Esophagectomy

BACKGROUND

Studies addressing both lymphovascular invasion (LVI) and perineural invasion (PNI) in patients with esophageal squamous cell carcinoma (ESCC) treated with or without neoadjuvant therapy are limited. We aimed to analyze the incidence and prognostic significance of LVI and PNI in patients with thoracic ESCC.

METHODS

This retrospective study included 520 patients with ESCC: 174 patients after neoadjuvant treatment followed by surgery and 346 after primary esophagectomy, from two medical centers. The relationships between LVI, PNI, and other histological factors were evaluated. The Cox regression model was used for survival analysis.

RESULTS

Positive LVI and PNI were noted in 35.6% and 22.4% of patients with residual primary tumor after neoadjuvant treatment and in 39.6% and 24.0% of patients who underwent primary esophagectomy, respectively. In patients with neoadjuvant treatments, the 5-year overall survival rates were 12.7% and 28.3% in patients with positive LVI and negative LVI, respectively (p = 0.001). The 5-year overall survival rates were 6.4% and 29.9% in patients with positive PNI and negative PNI, respectively (p < 0.001). In patients who did not receive neoadjuvant treatment, the 5-year overall survival rates were 28.2% and 61.1% in patients with positive LVI and negative LVI, respectively (p < 0.001). The 5-year overall survival rates were 30.2% and 52.5% in patients with positive PNI and negative PNI (p < 0.001). In subgroup analysis, the presence of PNI was an independent prognostic factor in patients with neoadjuvant treatments, whereas the presence of LVI had more significant prognostic impact in patients with node-negative ESCC after primary esophagectomy.

CONCLUSIONS

Both LVI and PNI statuses are significant prognostic factors for patients with ESCC. However, the prognostic impact of LVI was majorly in the subgroup of node-negative patients who received primary esophagectomy.

Molecular profiling of thymoma with myasthenia gravis: Risk factors of developing myasthenia gravis in thymoma patients

OBJECTIVE

Thymoma is a rare epithelial tumor arising from the thymus in the anterior mediastinum. Nearly 50% of patients with thymoma develop myasthenia gravis, which is an indication of a poor long-term prognosis. Here, we identified specific and effective molecular markers for predicting in the development of myasthenia gravis patients with thymoma.

MATERIAL AND METHODS

We investigated molecular profiling based on RNA-sequencing (RNA-seq) for myasthenia gravis development in patients with thymoma. RNA was extracted from 34 patients with thymoma, 16 of whom had myasthenic and 18 of whom did not, and transcriptome profiles were analyzed through next-generation sequencing.

RESULTS

We discovered 140 differential expressed genes associated with myasthenia gravis in thymoma patients. The four genes, hypoxia-inducible factor 3 alpha (HIF3A), insulin-like growth factor-binding protein 1, pyruvate dehydrogenase kinase, and Krüppel-like factor 15 were differentially expressed in patients with thymoma who has myasthenia gravis and were validated by quantitative polymerase chain reaction. HIF3A expression was significantly higher in patients with myasthenia gravis than in those without.

CONCLUSION

HIF3A is aberrantly expressed in patient with thymoma who has myasthenia gravis and may be involved in the development of myasthenia gravis in thymoma patient.

GLK/MAP4K3 overexpression associates with recurrence risk for non-small cell lung cancer

Lung cancer is the leading cause of cancer death worldwide. Non-small cell lung cancer (NSCLC) accounts for 85% of total lung cancers; 40% to 60% of NSCLC patients die of cancer recurrence after cancer resection. Since GLK (also named MAP4K3) induces activation of NF-κB, which contributes to tumor progression, we investigated the role of GLK in NSCLC. GLK protein levels of 190 samples from pulmonary tissue arrays and 58 pulmonary resection samples from stage I to stage III NSCLC patients were studied using immunohistochemistry or immunoblotting. High levels of GLK proteins were detected in pulmonary tissues from NSCLC patients. Elevated GLK protein levels were correlated with increased recurrence risks and poor recurrence-free survival rates in NSCLC patients after adjusting for pathologic stage, smoking status, alcohol status, and EGFR levels. Thus, GLK is a novel prognostic biomarker for NSCLC recurrence.

The impact of pathological complete response after neoadjuvant chemoradiotherapy in locally advanced squamous cell carcinoma of esophagus

BACKGROUND

The impact of pathological complete response after neoadjuvant chemoradiotherapy on survival of patients with squamous cell carcinoma of esophagus is still controversial. We retrospectively investigated the survival outcome in this group of patients.

METHODS

Ninety-eight patients with locally advanced squamous cell carcinoma of esophagus, who received neoadjuvant chemoradiotherapy were included in this retrospective analysis. Treatment protocols were radiotherapy with standard dose 50.4 Gy/28 fr, and chemotherapy with cisplatin 20 mg/m² and 5-FU 800 mg/m² for 4 days given on week 1 and 5. After neoadjuvant chemoradiotherapy is completed, patients who were eligible for surgery received surgery within 4-6 weeks. Patients who were not suitable for surgery were shifted to definite chemoradiotherapy. The primary end points were overall survival and progression-free survival.

RESULTS

Sixty-eight patients out of the ninety-eight patients received surgery after neoadjuvant chemoradiotherapy. There were 32 patients who achieved pathological complete response with a pCR rate of 47%. Thirty patients were shifted to definite concurrent chemoradiotherapy. The 2-year overall survival rate was 81.3% in the patients whose tumors showed a pCR and 58.3% in the patients with tumors that had a pathological partial response (p = 0.025). The 2-year overall survival in patients who received neoadjuvant chemoradiotherapy followed by surgery and definite chemoradiotherapy were 69.1% and 40.0%, respectively. There are 13 patients experienced grade 3-4 adverse event.

CONCLUSION

Pathological complete response after neoadjuvant chemoradiotherapy is associated with a significant survival benefit in patients with locally advanced squamous cell carcinoma of esophagus. The toxicities related to neoadjuvant chemoradiotherapy were tolerable.

Phase II study of preoperative concurrent chemoradiotherapy with oxaliplatin for locally advanced esophageal cancer

BACKGROUND

We investigated preoperative concurrent chemoradiotherapy (CCRT) with oxaliplatin for locally advanced, potentially operative esophageal cancer in this Phase II study.

METHODS

Between October 2009 and October 2011, 35 consecutive patients with newly diagnosed esophageal cancer clinical stage T3-4, N0-1, M0 were enrolled into this study. One dose of chemotherapy with oxaliplatin (35 mg/m²) on Day 1 and Day 2, leucovorin (200 mg/m²) on Day 1, and 5-fluorouracil [5-FU; 2400 mg/m² intravenously (i.v.) administered continuously for 48 hours] on Day 1 was administered 2 weeks before preoperative CCRT. During preoperative CCRT, radiation dose of 4500 cGy in 25 fractions was administered to the clinical target volume and 5000 cGy to 5040 cGy in 25 fractions was administered to the gross tumor volume; chemotherapy is administered concomitantly with oxaliplatin (45 mg/m²) on Day 1 of radiation therapy (R/T) every 14 days; 5-FU (400 mg/m² i.v. bolus for 1 hour) for 5 days on Weeks 1 and 5 of R/T. Operation was performed 4-6 weeks after preoperative CCRT. Acute toxicity profile, overall survival rate, disease-free survival rate, distant metastasis failure-free survival rate, and local recurrence rate were evaluated.

RESULTS

Four patients withdrew from the study. The total number of patients in this analysis was 31. The resection rate was 64.5%. The pathologic complete response rate was 15%. The overall median survival was 19.3 months. The 5-year overall survival rate was 37.8%. The 5-year disease-free survival rate was 31.1%. The 5-year distant metastasis failure-free survival rate was 40.7% (50.56% for patients with operation; 27.2% for patients without operation, p=0.0298). The acute toxicities were mild, and no Grade 3 or above hematologic toxicity was noted. There was only one patient with Grade 3 esophagus toxicity. Grade 3 lung toxicity occurred in only three patients.

CONCLUSION

Preoperative chemoradiotherapy with oxaliplatin in the treatment of locally advanced, potentially resectable esophageal cancer is feasible and safe.

Feasibility of intensity-modulated radiotherapy for esophageal cancer in definite chemoradiotherapy

BACKGROUND

Esophageal cancer is a highly lethal malignancy, and its treatment has undergone a major evolution over the past 15 years. The objective of this study was to report our experience on the efficacy of definite chemoradiotherapy with the intensity-modulated radiotherapy (IMRT) technique in treating locally advanced esophageal cancer.

METHODS

From September 2004 to November 2011, 39 patients with biopsy-proven esophageal cancer, clinical stage T1-4N0-3M0 according to the American Joint Committee on Cancer 7(th) edition were enrolled. In these enrolled cases, either the tumor was unresectable or the patients refused surgery. All patients received a total radiation dose of 40-56 Gy in 20-28 fractions using IMRT planning. Five to seven radiation beam angles were designed according to the specific shape of the clinical target volume (CTV) and were delivered by a linear accelerator with photons of 6-10 MV energy. The gross tumor volume, CTV, planning target volume, and the organs at risk were outlined, and the homogeneity index (HI) and the conformity index (CI) were calculated. The treatment-related toxicities were also reviewed.

RESULTS

The mean follow-up time was 22.4 months (range, 2.0-91.0 months). The 2- and 3-year overall survival rates were 30% and 28%, respectively. The most common Grade 3/4 toxicity was hematologic toxicity (43.6%). The IMRT plans showed high-dose homogeneity to the target, with a calculated HI of 0.9. The calculated CI of 0.8 also showed high conformity treatment dose to target within an acceptable dose range. For the total lungs, the average mean dose was 1313.7 cGy. The V5 and V20 of the total lungs were 67.8% and 23.4%, respectively. For the heart, the average mean dose was 2319.2 cGy. The V30 and V35 of the heart were 30.2% and 21.5%, respectively.

CONCLUSION

Concurrent chemoradiotherapy using the IMRT technique for treating locally advanced unresectable esophageal cancer is feasible, with better conformity of target volume as well as improved sparing of organs at risk.

EGFR mutation and lobar location of lung adenocarcinoma

The objective of this study was to investigate the associations among lung cancer location, and epidermal growth factor receptor (EGFR) mutation status. Treatment-naive, pathologically confirmed lung adenocarcinomas with tumor specimens available for genetic analysis were included from 2011 through 2014. Overall, 1771 patients with lung adenocarcinoma were included for analysis, after excluding those with carcinoma not otherwise specified, or synchronous multiple primary lung cancers. The median age was 64 years, and the female:male and never smoker:ever smoker ratios were 930:855 (52:48%) and 1167:604 (65:35%), respectively. The EGFR mutation rate was 56%. Among patients, 1093 (62%) had primary tumors in the upper lobes. Compared with the characteristics of the EGFR wild-type, tumors with EGFR activating mutations were more common in women (P < 0.001), never smokers (P < 0.001), and in the upper lobes (P = 0.004). Among EGFR activating mutations, compared with the EGFR exon 19 deletion, L858R mutation were more common in women (P = 0.002), never smokers (P = 0.038), and the upper lobes P < 0.0005). The present study is the first to address that different pulmonary lobar locations might harbor different EGFR mutation subtypes. We demonstrated that adenocarcinomas with L858R mutation, rather than exon 19 deletion or wild-type EGFR gene, prefer to locate over the upper lungs. This phenomenon was more significant in females and never-smokers, implying the result of complex interactions between genetic susceptibility and environmental factors. Therefore, EGFR L858R mutation and exon 19 deletion may not be identical disease entity from the point of carcinogenesis.

Long-term results of coronary artery bypass grafting in patients with dialysis-dependent renal failure

AIM

Coronary artery disease is the main cause of mortality and morbidity in dialysis-dependent renal failure patients. Both the prevalence and incidence of renal failure are high in Taiwan. However, there were few reports exploring the outcome of coronary aortic bypass grafting (CABG) in these patients. The aim of this study was to determine the survival outcome and risk factors for mortality from CABG in this population.

METHODS

The operative, early postoperative and late results of 170 dialysis patients undergoing isolated coronary artery bypass grafting from January, 2000 to January, 2012 were retrospectively reviewed. Operative mortality, long-term survival, and risk factors were analyzed.

RESULTS

One hundred and seventeen patients (68.8%) were male, and the mean age was 61.5±10.3 years (range, 34-86 years). Follow-up was 40.3±32.1 months. Operative mortality was 8.2%. Actuarial survival, including operative mortality, was 81±3% at 1 year, 68±4% at 3 years, 58±5% at 5 years and 49±6% at 10 years, better than the natural course of dialysis-dependent renal failure patients. Age, emergent operation, postoperative ventricular tachycardia or fibrillation, postoperative intra-aortic balloon pump insertion, gastrointestinal bleeding, and left internal mammary artery graft were significant predictors of operative or long term mortality. Most causes of late death were due to infection or cardiac events.

CONCLUSION

CABG in dialysis patients is associated with a higher incidence of complications, but has acceptable mortality. CABG is beneficial in this population. Internal mammary artery grafting may provide more favorable long term outcomes.

R331W Missense Mutation of Oncogene YAP1 Is a Germline Risk Allele for Lung Adenocarcinoma With Medical Actionability

PURPOSE

Adenocarcinoma is the most dominant type of lung cancer in never-smoker patients. The risk alleles from genome-wide association studies have small odds ratios and unclear biologic roles. Here we have taken an approach featuring suitable medical actionability to identify alleles with low population frequency but high disease-causing potential.

PATIENTS AND METHODS

Whole-genome sequencing was performed for a family with an unusually high density of lung adenocarcinoma with available DNA from the affected mother, four affected daughters, and one nonaffected son. Candidate risk alleles were confirmed by matrix-assisted laser desorption ionization time of flight mass spectroscopy. Validation was conducted in an external cohort of 1,135 participants without cancer and 1,312 patients with lung adenocarcinoma. Family follow-ups were performed by genotyping the relatives of the original proband and the relatives of the identified risk-allele carriers. Low-dose computed tomography scans of the chest were evaluated for lung abnormalities.

RESULTS

YAP1 R331W missense mutation from the original family was identified and validated in the external controls and the cohort with lung adenocarcinoma. The YAP1 mutant-allele carrier frequency was 1.1% in patients with lung adenocarcinoma compared with 0.18% in controls (P = .0095), yielding an odds ratio (adjusted for age, sex, and smoking status) of 5.9. Among the relatives, YAP1-mutant carriers have overwhelmingly higher frequencies of developing lung adenocarcinoma or ground-glass opacity lung lesions than those who do not carry the mutation (10:0 v 1:7; P < .001). YAP1 mutation was shown to increase the colony formation ability and invasion potential of lung cancer cells.

CONCLUSION

These results implicated YAP1 R331W as an allele predisposed for lung adenocarcinoma with high familial penetrance. Low-dose computed tomography scans may be recommended to this subpopulation, which is at high risk for lung cancer, for personalized prevention and health management.

To evaluate the treatment response of locally advanced esophageal cancer after preoperative chemoradiotherapy by FDG-PET/CT scan

BACKGROUND

This study was designed to gauge the effectiveness of evaluation of tumor response and prognosis by positron emission tomography with 18F-fluorodeoxyglucose-positron emission tomography (FDG-PET) before and after preoperative chemoradiotherapy in patients with esophageal cancer.

METHODS

Forty-nine patients from October 2008 to September 2012 with locally advanced stage esophageal carcinoma, clinical stage T2-4N0-3M0, who underwent preoperative chemoradiotherapy (pre-CRT) followed by esophagectomy were enrolled in our study. All patients underwent two FDG-PET scans to compare those results with the pathologic results. Metabolic response of the primary tumor by the percentage change of the SUVmax/1 hour (ΔSUV) before and after pre-CRT (ΔSUV was calculated as the difference between pre-CRT SUVmax/1 hour and post-CRT SUVmax/1 hour divided by pre-CRT SUVmax/1 hour at esophageal tumor) was evaluated for overall survival (OS), disease free survival (DFS), local recurrence rate, and distant failure free survival (DFFS). Prognostic factors such as age, different regimen of chemotherapy, pathologic stage, FDG-PET stage, endoscopic esophageal tumor length, and ΔSUV were analyzed. The number of highly suspect malignant lymph nodes was calculated by PET when SUVmax/1 hour ≥2.5 and by surgical removal. Sensitivity and specificity of regional lymph node detection by PET were also recorded.

RESULTS

Upon univariate analysis, overall survival rate was related to ΔSUV >60% (p = 0.045), pathological N stage (p = 0.001), and endoscopic total length of esophageal tumor (p = 0.005). The result of FDG-PET scan after pre-CRT had high specificity (96.7%) but low sensitivity (45.8%) in predicting the residual malignant lymph node numbers. The positive and the negative prediction rates were 44% and 96%, respectively. The result of the FDG-PET after pre-CRT showed upstaged in 16 patients (32.6%), downstaged in nine patients (18.3%), and the same stage in 24 patients (48.9%) when compared with the pathologic stage [corrected].

CONCLUSION

The change of SUVmax can be a tool for evaluating tumor response after pre-CRT. There is also a trend of good prognosis in overall survival rate when ΔSUV value is >60%.

Identification of regulatory SNPs associated with genetic modifications in lung adenocarcinoma

Background

Although much research effort has been devoted to elucidating lung cancer, the molecular mechanism of tumorigenesis still remains unclear. A major challenge to improve the understanding of lung cancer is the difficulty of identifying reproducible differentially expressed genes across independent studies, due to their low consistency. To enhance the reproducibility of the findings, an integrated analysis was performed to identify regulatory SNPs. Thirty-two pairs of tumor and adjacent normal lung tissue specimens were analyzed using Affymetrix U133plus2.0, Affymetrix SNP 6.0, and Illumina Infinium Methylation microarrays. Copy number variations (CNVs) and methylation alterations were analyzed and paired t-tests were used to identify differentially expressed genes.

Results

A total of 505 differentially expressed genes were identified, and their dysregulated patterns moderately correlated with CNVs and methylation alterations based on the hierarchical clustering analysis. Subsequently, three statistical approaches were performed to explore regulatory SNPs, which revealed that the genotypes of 551 and 66 SNPs were associated with CNV and changes in methylation, respectively. Among them, downstream transcriptional dysregulation was observed in 9 SNPs for CNVs and 4 SNPs for methylation alterations.

Conclusions

In summary, these identified SNPs concurrently showed the same direction of gene expression changes with genetic modifications, suggesting their pivotal roles in the genome for non-smoking women with lung adenocarcinoma.

Electronic supplementary material

The online version of this article (doi:10.1186/s13104-015-1053-8) contains supplementary material, which is available to authorized users.

Epidermal growth factor activates telomerase activity by direct binding of Ets-2 to hTERT promoter in lung cancer cells

Growth signals are directly or indirectly involved in telomerase regulation. In this study, we investigated molecular mechanisms of the effect of EGF (epidermal growth factor) on regulating hTERT (human telomerase reverse transcriptase) expression. To elucidate specific transcription factors involved in EGF-stimulated hTERT transcription in A549 and H1299 lung cancer cells, transcription factors drives hTERT promoter activity, such as Myc, Mad, and Ets-2, was evaluated on luciferase reporter assay. The upregulation of hTERT promoter by Ets-2 and Myc were abolished by Mad. Using DAPA (DNA affinity precipitation assay), Ets-2 binding to SNP (T) was stronger than Ets-2 binding to SNP (C) at -245 bp upstream of the transcription start site within the core promoter of hTERT. Ets-2 silence by siRNA decreased hTERT expression at mRNA and protein levels. The regulation of hTERT promoter by EGF/Ets-2 was diminished via the EGFR kinase signal pathway-specific inhibitors AG1478 and Iressa. Inhibitors of Erk and Akt inhibited Ets-2-activated hTERT promoter activity. These data suggested that Ets-2, a genuine cancer-specific transcription factor, is actively involved in EGFR kinase-induced hTERT overexpression pathway in lung cancer cells. Blockage of this pathway may contribute to targeted gene therapy in lung cancer.

SNP rs10248565 in HDAC9 as a novel genomic aberration biomarker of lung adenocarcinoma in non-smoking women

BACKGROUND

Numerous efforts have been made to elucidate the etiology and improve the treatment of lung cancer, but the overall five-year survival rate is still only 15%. Although cigarette smoking is the primary risk factor for lung cancer, only 7% of female lung cancer patients in Taiwan have a history of smoking. Since cancer results from progressive accumulation of genetic aberrations, genomic rearrangements may be early events in carcinogenesis.

RESULTS

In order to identify biomarkers of early-stage adenocarcinoma, the genome-wide DNA aberrations of 60 pairs of lung adenocarcinoma and adjacent normal lung tissue in non-smoking women were examined using Affymetrix Genome-Wide Human SNP 6.0 arrays. Common copy number variation (CNV) regions were identified by ≥30% of patients with copy number beyond 2 ± 0.5 of copy numbers for each single nucleotide polymorphism (SNP) and at least 100 continuous SNP variant loci. SNPs associated with lung adenocarcinoma were identified by McNemar's test. Loss of heterozygosity (LOH) SNPs were identified in ≥18% of patients with LOH in the locus. Aberration of SNP rs10248565 at HDAC9 in chromosome 7p21.1 was identified from concurrent analyses of CNVs, SNPs, and LOH.

CONCLUSION

The results elucidate the genetic etiology of lung adenocarcinoma by demonstrating that SNP rs10248565 may be a potential biomarker of cancer susceptibility.

The relationship between Helicobacter pylori and cancer risk

OBJECTIVES

This study investigated the correlation between Helicobacter pylori (HP) and cancer risk. We compared the age, sex, and comorbidity of cancer patients both infected and not infected by HP.

METHODS

In this study, we compared a comparison cohort (N=24,088) and an HP cohort (N=6022), both taken from the NHI database. We performed a statistical analysis with the multivariable Cox proportional model to estimate the risk of developing cancer for a comparison and the HP cohort.

RESULTS

Our results showed that the proportion of peptic ulcers in the HP cohort was nearly 4 times higher than that in the comparison cohort. The HP cohort was significantly associated with increased colorectal (HR=1.73, 95% CI=1.08-2.77), stomach (HR=5.21, 95% CI=2.46-11.05) and pancreatic (HR=2.77, 95% CI=1.04-7.39) cancer risks compared to the comparison cohort. In addition, the cancer risk in the HP cohort was considerably higher than that in the comparison cohort when hypertension was absent in both cohorts.

CONCLUSIONS

In this study, we proposed a method to investigate the correlation between HP infection and cancer risk. We found that HP infection is associated with the development of colorectal, stomach, and pancreatic cancers, and could thus be an independent carcinogenic risk factor.

Pulmonary sequestration-differences in diagnosis and treatment in a single institution

BACKGROUND

Pulmonary sequestration (PS) is a rare congenital lung malformation. In this study, we evaluated the diagnosis and treatment of PS in 31 adult patients at a single institution.

METHODS

A retrospective review of all patients 16 years of age and older with PS in a single institution between January 1985 and January 2011 was conducted. The following data were analyzed for all patients: major symptoms, diagnostic procedures, operative findings, operative techniques, postoperative complications, and outcome.

RESULTS

Our study involved 31 patients, 17 male and 14 female, with an average age of 32.1 (17-57) years, who underwent surgical intervention for PS. The preoperative symptoms of these patients included cough, hemoptysis, fever, pneumonia, and chest pain. Thirty (96.8%) patients were diagnosed by thoracic computed tomography. Of the 31 patients, 29 were diagnosed with intralobar pulmonary sequestration and two had extralobar pulmonary sequestration. Surgical procedures for intralobar pulmonary sequestration included lobectomy in 22 patients (including one thoracoscopic lobectomy), segmentectomy in six, and wedge resection in one of the patients. Thoracoscopic simple mass excision was performed on the two patients with extralobar pulmonary sequestration. Two patients had a postoperative complication (prolonged air leak in 1 patient and postoperative hemothorax in the other). The average hospital stay for all study patients was 6.4 (4-18) days, and there was no mortality.

CONCLUSION

Diagnostic tools may enable the clinician to obtain a definitive diagnosis in patients where there is a strong suspicion of PS via a noninvasive procedure. Computed tomography angiography may be the diagnostic imaging method of choice for optimal evaluation of the sequestrated lung and its vascular supply.

Glutathione S-transferase mu2 suppresses cancer cell metastasis in non-small cell lung cancer

Glutathione S-transferase mu2 (GST-M2) is a phase II detoxification enzyme. Low expression of GST-M2 in lung cancers is due to hypermethylation of its promoter. Lung cancer with the GST mu-null genotype is associated with shorter survival. However, a correlation between GST-M2 and important clinical parameters, as well as the migration of GST-M2-defective cells in lung cancer, has not been established. In the present study, we investigate the role of GST-M2 in cell migration and actin disassembly in lung cancer cells. GST-M2 and CCN2 mRNA levels were significantly reduced in non-small cell lung cancer (NSCLC) tumors when compared with matched normal lung tissues in 82 patients with NSCLC. We found that high expressions of both GST-M2 and CCN2 are correlated with favorable survival of patients with lung cancer when compared with similar patients without GST-M2 or CCN2 expression. GST-M2 can induce CCN2 expression by driving the CCN2 proximal promoter. Overexpression of GST-M2 decreases the formation of filopodia, resulting in remodeling of the reorganized cytoskeletons. Overexpression of GST-M2 significantly suppressed cancer cell migration on wound-healing assay. In addition, overexpression of GST-M2 dramatically reduced tumor growth and metastasis in a xenograft mouse model. These data highlight the potential of GST-M2 as a novel tumor suppressor. GST-M2 increases the expression of CCN2 in lung cancer cells, which inhibits cancer cell migration in lung cancer and animal models.

Refractory ventricular tachycardia in a long QT syndrome child successfully controlled by left cardiac sympathetic denervation

Long QT syndrome is a congenital disorder accompanied by a high incidence of sudden cardiac death. β-adrenergic blockade is the therapy of choice, and it is successful in 75-80% of patients. However, for those in whom refractory arrhythmia or cardiac events are not prevented by medication, the literature suggests that left cardiac sympathetic denervation may be useful. Here we present a girl 20 months of age with refractory ventricular tachycardia due to long QT syndrome successfully treated by left cardiac sympathetic denervation. There was no significant complication.

Protein arginine methyltransferase 5 is a potential oncoprotein that upregulates G1 cyclins/cyclin-dependent kinases and the phosphoinositide 3-kinase/AKT signaling cascade

Increasing evidence suggests that PRMT5, a protein arginine methyltransferase, is involved in tumorigenesis. However, no systematic research has demonstrated the cell-transforming activity of PRMT5. We investigated the involvement of PRMT5 in tumor formation. First, we showed that PRMT5 was associated with many human cancers, through statistical analysis of microarray data in the NCBI GEO database. Overexpression of ectopic PRMT5 per se or its specific shRNA enhanced or reduced cell growth under conditions of normal or low concentrations of serum, low cell density, and poor cell attachment. A stable clone that expressed exogenous PRMT5 formed tumors in nude mice, which demonstrated that PRMT5 is a potential oncoprotein. PRMT5 accelerated cell cycle progression through G1 phase and modulated regulators of G1; for example, it upregulated cyclin-dependent kinase (CDK) 4, CDK6, and cyclins D1, D2 and E1, and inactivated retinoblastoma protein (Rb). Moreover, PRMT5 activated phosphoinositide 3-kinase (PI3K)/AKT and suppressed c-Jun N-terminal kinase (JNK)/c-Jun signaling cascades. However, only inhibition of PI3K activity, and not overexpression of JNK, blocked PRMT5-induced cell proliferation. Further analysis of PRMT5 expression in 64 samples of human lung cancer tissues by microarray and western blot analysis revealed a tight association of PRMT5 with lung cancer. Knockdown of PRMT5 retarded cell growth of lung cancer cell lines A549 and H1299. In conclusion, to the best of our knowledge, we have characterized the cell-transforming activity of PRMT5 and delineated its underlying mechanisms for the first time.

Lipocalin 2, a new GADD153 target gene, as an apoptosis inducer of endoplasmic reticulum stress in lung cancer cells

Endoplasmic reticulum (ER) stress is activated under severe cellular conditions. GADD153, a member of the C/EBP family, is an unfolded protein response (UPR) responsive transcription factor. Increased levels of lipocalin 2, an acute phase protein, have been found in several epithelial cancers. The aim of this study is to investigate the function of lipocalin 2 in lung cancer cells under ER stress. Treatment with thapsigargin, an ER stress activator, led to increases in cytotoxicity, ER stress, apoptosis, and lipocalin 2 expression in A549 cells. GADD153 silencing decreased lipocalin 2 expression in A549 cells. On chromatin immunoprecipitation assay, ER stress increased GADD153 DNA binding to lipocalin 2 promoter. Furthermore, silencing of lipocalin 2 mitigated ER stress-mediated apoptosis in A549 cells. Our findings demonstrated that lipocalin 2 is a new GADD153 target gene that mediates ER stress-induced apoptosis.

EGFR exon 19 in-frame deletion and polymorphisms of DNA repair genes in never-smoking female lung adenocarcinoma patients

We explored potential associations between genetic polymorphisms in genes related to DNA repair and detoxification metabolism and epidermal growth factor receptor (EGFR) mutations in a cohort of 410 never-smoking patients with lung adenocarcinoma. Multivariate-adjusted odds ratios (aORs) and corresponding 95% confidence intervals (CI) of EGFR mutation status in association with the genotypes of DNA repair and detoxification metabolism genes were evaluated using logistic regression analysis. We found an association between in-frame deletion in EGFR exon 19 and a single nucleotide polymorphism (SNP) rs1800566C/T located in NQO1 (aOR, 2.2 with 95% CI, 1.0-4.8) in female never-smokers. The SNP rs744154C/G in ERCC4 was also associated with the EGFR exon 19 in-frame deletion both in never-smokers (aOR, 1.7 with 95% CI, 1.0-3.0) and female never-smokers (aOR, 1.9 with 95% CI, 1.0-3.6). Although the association was marginally significant in multivariate logistic regression analysis, the A/A genotype of rs1047840 in EXO1 was associated with a 7.6-fold increase in the occurrence of the EGFR exon 19 in-frame deletion in female never-smokers. Moreover, risk alleles in NQO1, ERCC4 and EXO1 were associated with an increasing aOR of the EGFR exon 19 in-frame deletion both in never-smokers (p = 0.007 for trend) and female never-smokers (p = 0.002 for trend). Our findings suggest that the in-frame deletion in EGFR exon 19 is associated with polymorphisms in DNA repair and detoxification metabolism genes in never-smoking lung adenocarcinoma patients, especially in females.

Detecting the effect of targeted anti-cancer medicines on single cancer cells using a poly-silicon wire ion sensor integrated with a confined sensitive window

A mold-cast polydimethylsiloxane (PDMS) confined window was integrated with a poly-silicon wire (PSW) ion sensor. The PSW sensor surface inside the confined window was coated with a 3-aminopropyltriethoxysilane (γ-APTES) sensitive layer which allowed a single living cell to be cultivated. The change in the microenvironment due to the extracellular acidification of the single cell could then be determined by measuring the current flowing through the PSW channel. Based on this, the PSW sensor integrated with a confined sensitive window was used to detect the apoptosis as well as the effect of anti-cancer medicines on the single living non-small-lung-cancer (NSLC) cells including lung adenocarcinoma cancer cells A549 and H1299, and lung squamous-cell carcinoma CH27 cultivated inside the confined window. Single human normal cells including lung fibroblast cells WI38, lung fibroblast cells MRC5, and bronchial epithelium cell Beas-2B were tested for comparison. Two targeted anti-NSCLC cancer medicines, Iressa and Staurosporine, were used in the present study. It was found that the PSW sensor can be used to accurately detect the apoptosis of single cancer cells after the anti-cancer medicines were added. It was also found that Staurosporine is more effective than Iressa in activating the apoptosis of cancer cells.

Abstract 731: TPX2 overexpression is associated with tumorigenesis and patient outcome of esophageal squamous cell carcinoma

Background Esophageal squamous cell carcinoma (ESCC) is an aggressive malignancy with dismal prognosis. By microarray data analysis, we aim to identify molecular changes involved in ESCC tumorigenesis and investigate their clinical relevance. Methods Five microarray datasets were obtained from GEO database. Differentially expressed genes (DEGs) were identified using t-test with permutation. Pathway analysis was performed with LS/KS permutation statistics and Efron-Tibshirani's gene set analysis. As for the validation, we studied: (i) mRNA expression of tumor (T) and matched normal (N) tissues in 16 ESCC cases from Taipei and Taichung Veterans General Hospital by the Affymetrix HG U133A array, (ii) protein expression of target genes in 97 ESCC specimens by immunohistochemical stains (IHC), and (iii) impact of TPX2 expression on tumor cell proliferation in ESCC cell line (CE81T). Results A set of 69 DEGs (46 up and 23 down-regulated in T) was found to be overlapped among five datasets. Pathway analysis revealed eight out of 306 gene sets to have altered expression between T and N esophageal epithelium in at least three datasets. The “Role of Ran in mitotic spindle regulation” pathway, which includes AURKA and TPX2 as key regulators, was selected for further investigation. Verification by microarray analysis of 16 ESCC patients identified 12 out of 306 gene sets to have altered expression between T and N specimens. In accordance with previous results, the “Role of Ran in mitotic spindle regulation” pathway remains a significant overexpressed gene set. Both AURKA and TPX2 showed overexpression in tumor tissues (AURKA, T/N ratio = 3.13, p = 2e-07; TPX2, T/N ratio = 3.22, p = 3e-07). IHC verification showed positive AURKA and TPX2 expression in 88.4% and 90.6% of ESCC specimens, respectively. Although the expression of AURKA and TPX2 did not correlate with any clinicopathological factor, univariate survival analysis indicated high TPX2 expression as a significant prognostic factor for overall (OS) and disease-free survival (DFS) (p = 0.036 for OS and 0.038 for DFS). There was also a non-significant trend toward worse outcome in patients with high AURKA expression. In multivariate analysis, high TPX2 expression remained an independent prognostic factor (HR = 2.255, p = 0.005). To further investigate the effect of TPX2 expression, we performed MTT assay to determine cell growth of CE81T cell line after manipulating TPX2 expression level. Growth curves demonstrated that growths of vector-based TPX2 shRNA-mediated knockdown clones were inhibited compared with that of the parental and vector control groups (p &lt; 0.05 on day 4 and 5). Conclusions Using bioinformatics resources, which were validated by microarray analysis/IHC in our clinical cohorts, and manipulation of TPX2 expression in CE81T cell line, we demonstrated that TPX2 overexpression is associated with tumorigenesis and patient outcome of ESCC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 731. doi:1538-7445.AM2012-731

Integrated analyses of copy number variations and gene expression in lung adenocarcinoma

Numerous efforts have been made to elucidate the etiology and improve the treatment of lung cancer, but the overall five-year survival rate is still only 15%. Identification of prognostic biomarkers for lung cancer using gene expression microarrays poses a major challenge in that very few overlapping genes have been reported among different studies. To address this issue, we have performed concurrent genome-wide analyses of copy number variation and gene expression to identify genes reproducibly associated with tumorigenesis and survival in non-smoking female lung adenocarcinoma. The genomic landscape of frequent copy number variable regions (CNVRs) in at least 30% of samples was revealed, and their aberration patterns were highly similar to several studies reported previously. Further statistical analysis for genes located in the CNVRs identified 475 genes differentially expressed between tumor and normal tissues (p<10(-5)). We demonstrated the reproducibility of these genes in another lung cancer study (p = 0.0034, Fisher's exact test), and showed the concordance between copy number variations and gene expression changes by elevated Pearson correlation coefficients. Pathway analysis revealed two major dysregulated functions in lung tumorigenesis: survival regulation via AKT signaling and cytoskeleton reorganization. Further validation of these enriched pathways using three independent cohorts demonstrated effective prediction of survival. In conclusion, by integrating gene expression profiles and copy number variations, we identified genes/pathways that may serve as prognostic biomarkers for lung tumorigenesis.

Clustered genomic alterations in chromosome 7p dictate outcomes and targeted treatment responses of lung adenocarcinoma with EGFR-activating mutations

PURPOSE

Although epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been proven more effective for patients with lung adenocarcinoma with EGFR-activating mutation rather than wild type, the former group still includes approximately 30% nonresponders. The molecular basis of this substantial response heterogeneity is unknown. Our purpose was to seek molecular aberrations contributing to disease progression at the genome-wide level and identify the prognostic signature unique to patients with EGFR-activating mutation.

PATIENTS AND METHODS

We first investigated the molecular differences between tumors with EGFR-activating mutation and wild-type tumors by conducting high-density array comparative genomic hybridization on a collection of 138 adenocarcinoma tissues. We then used an independent group of 114 patients to validate the clinical relevance of copy-number alterations (CNAs) in predicting overall and disease-free survival. Finally, focusing on 23 patients with EGFR mutation receiving EGFR-TKI treatment, we investigated the association between CNAs and response to EGFR-TKIs.

RESULTS

We identified chromosome regions with differential CNAs between tumors with EGFR-activating mutation and wild-type tumors and found the aberration sites to cluster highly on chromosome 7p. A cluster of six representative chromosome 7p genes predicted overall and disease-free survival for patients with EGFR-activating mutation but not for those with wild type. Importantly, simultaneous presence of more genes with increased CNAs in this cluster correlated with less favorable response to EGFR-TKIs in patients with EGFR-activating mutation.

CONCLUSION

Our results shed light on why responses to EGFR-TKIs are heterogeneous among patients with EGFR-activating mutation. They may lead to better patient management in this population.

Electrical characterization of single cells using polysilicon wire ion sensor in an isolation window

A polysilicon wire (PSW) sensor can detect the H(+) ion density (pH value) of the medium coated on its surface, and different cells produce different extracellular acidification and hence different H(+) ion densities. Based on this, we used a PSW sensor in combination with a mold-cast polydimethylsiloxane (PDMS) isolation window to detect the adhesion, apoptosis and extracellular acidification of single normal cells and single cancer cells. Single living human normal cells WI38, MRC5, and BEAS-2B as well as non-small-cell lung cancer (NSCLC) cells A549, H1299, and CH27 were cultivated separately inside the isolation window. The current flowing through the PSW channel was measured. From the PSW channel current change as a function of time, we determined the cell adhesion time by observing the time required for the current change to saturate, since a stable extracellular ion density was established after the cells were completely adhered to the PSW surface. The apoptosis of cells can also be determined when the channel current change drops to zero. We found that all the NSCLC cells had a higher channel current change and hence a lower pH value than the normal cells anytime after they were seeded. The corresponding average pH values were 5.86 for A549, 6.00 for H1299, 6.20 for CH27, 6.90 for BEAS-2B, 6.96for MRC5, and 7.02 for WI38, respectively, after the cells were completely adhered to the PSW surface. Our results show that NSCLC cells have a stronger cell-substrate adhesion and a higher extracellular acidification rate than normal cells.

Hybrid combination of small subxiphoid incision and thoracoscopic thymectomy for juvenile myasthenia gravis

BACKGROUND/PURPOSE

Myasthenia gravis is an autoimmune disease that usually responds positively to treatment with thymectomy. Various approaches via video-assisted thoracic thymectomy as a substitute for conventional sternotomy have been reported. We reported a less invasive technique for thymectomy in pediatric groups.

METHODS

Four adolescents with juvenile myasthenia gravis all underwent hybrid combination of small subxiphoid incision and thoracoscopic thymectomy at our institute. Clinical characteristics and surgical outcome were consecutively collected.

RESULTS

In these 4 patients, 2 presented with Osserman class III and 2 with class IIb. The mean operative time was 180 minutes. There was no conversion to sternotomy, and there was only minimal blood loss. Follow-up duration was 3 to 64 months. Postoperatively, 1 patient had complete remission and 3 patients had improvement in clinical symptoms.

CONCLUSION

Hybrid combination of small subxiphoid incision and thoracoscopic thymectomy may be an effective alternative with low surgical invasiveness for treating juvenile myasthenia gravis.

Epigenetic mechanisms for silencing glutathione S-transferase m2 expression by hypermethylated specificity protein 1 binding in lung cancer

BACKGROUND

Glutathione S-transferases M2 (GST-M2) is a detoxifying enzyme. Low expression levels of GST-M2 have been detected in lung cancer cells. However, little is known about the regulation of GST-M2 in lung cancer cells. In this study, the authors investigated the epigenetic regulatory mechanisms of GST-M2 in lung cancer cells.

METHODS

The authors evaluated the promoter methylation of GST-M2 in lung cancer cells after treatment with the DNA methyltransferase (DNMT) inhibitor 5'-aza-2'-deoxycytidine (5'-aza-dC). Reporter activity assays, chromatin immunoprecipitation (ChIP), electrophoretic mobility-shift assays, and small interfering RNA (siRNA) assays were used to determine whether the methylation of specificity protein 1 (Sp1) affected binding to the GST-M2 promoter or regulated GST-M2 transcription. Real-time polymerase chain reaction was used to determine GST-M2 and DNMT-3b messenger RNA levels in 73 nonsmall cell lung cancer (NSCLC) tissues.

RESULTS

GST-M2 expression was restored after treatment with 5'-aza-dC in lung cancer cells. GST-M2 exhibited high frequency of promoter hypermethylation in lung cancer cells and NSCLC tumor tissues. CpG hypermethylation abated Sp1 binding to the GST-M2 promoter in lung cancer. Knockdown of Sp1 in normal lung cells reduced GST-M2 expression, and silencing of DNMT-3b increased GST-M2 expression in lung cancer cells. In addition, DNMT-3b expression was significantly higher in lung tumors with low levels of GST-M2 expression than in lung tumors with high levels of GST-M2 expression, especially among women and among patients who had stage I disease.

CONCLUSIONS

Epigenetic silencing of GST-M2 was distinguished from Sp1-mediated GST-M2 transcriptional expression. The authors concluded that this represents a mechanism that leads to decreased expression of GST-M2 in lung cancer cells.

Clinical significance of tumor suppressor PTEN in colorectal carcinoma

BACKGROUND

It has been demonstrated that the deletion, mutation, hypermethylation and subcellular location of the tumor suppressor phosphatase and tensin homologue (PTEN) are closely correlated with carcinogenesis, progression and prognosis of malignancy. Both mutation and the microsatellite instability of the PTEN gene influence regulation of the PI3K/Akt signaling pathway. This study investigated whether loss of nuclear PTEN is correlated with chemosensitivity, clinicopathological parameters and survival.

METHODS

Intracellular levels of PTEN of multiple cell lines of colorectal carcinoma (CRC) were evaluated by Western blotting and immunocytochemistry. The chemosensitivity of cell lines with various expression levels of PTEN was evaluated using 5-flurouracil (5-FU), oxaliplatin and irinotecan (CPT), and clinical significance was evaluated by immunohistochemical analysis of 133 CRC specimens.

RESULTS

Colon cancer cell lines HT-29, LoVo and SW480 differed in expression of PTEN, with high, moderate and low levels, respectively. HT-29 and LoVo PTEN expression was suppressed by a low concentration of 5-FU and oxaliplatin; however, SW480 was insensitive to these chemotherapeutic agents. Nuclear PTEN was overexpressed in most (>80%) normal colon mucosa samples, but the incidence significantly decreased (89.2% → 53.4%) in the CRC group. PTEN in the nucleus was negatively correlated with tumor size and vascular invasion in CRC, and CRC patients with negative PTEN expression in the nucleus exhibited poor survival.

CONCLUSION

Cell lines with a high expression of PTEN are sensitive to chemotherapy with 5-FU and oxaliplatin. Nuclear PTEN expression gradually decreases after malignant transformation, and loss of PTEN expression in the nucleus is associated with tumor progression and poor clinical outcome in CRC.

Identification of a novel biomarker, SEMA5A, for non-small cell lung carcinoma in nonsmoking women

BACKGROUND

Although cigarette smoking is the major risk factor for lung cancer, only 7% of female lung cancer patients in Taiwan have a history of smoking. The genetic mechanisms of carcinogenesis in nonsmokers are unclear, but semaphorins have been suggested to play a role as lung tumor suppressors. This report is a comprehensive analysis of the molecular signature of nonsmoking female lung cancer patients in Taiwan, with a particular focus on the semaphorin gene family.

METHODS

Sixty pairs of tumor and adjacent normal lung tissue specimens were analyzed by using Affymetrix U133plus2.0 expression arrays. Differentially expressed genes in tumor tissues were identified by a paired t test and validated by reverse transcriptase-PCR and immunohistochemistry. Functional analysis was conducted by using Ingenuity Pathway Analysis as well as gene set enrichment analysis and sigPathway algorithms. Kaplan-Meier survival analyses were used to evaluate the association of SEMA5A expression and clinical outcome.

RESULTS

We identified 687 differentially expressed genes in non-small cell lung carcinoma (NSCLC). Many of these genes, most notably the semaphorin family, were participants in the axon guidance signaling pathway. The downregulation of SEMA5A in tumor tissue, both at the transcriptional and translational levels, was associated with poor survival among nonsmoking women with NSCLC.

CONCLUSIONS

In summary, several semaphorin gene family members were identified as potential therapeutic targets, and SEMA5A may be useful as a prognostic biomarker for NSCLC, which may also be gender specific in Taiwanese patients.

IMPACT

A novel biomarker for NSCLC is identified.

N-acetyl cysteine mitigates curcumin-mediated telomerase inhibition through rescuing of Sp1 reduction in A549 cells

Curcumin is a natural compound that has been extensively observed due to its potential as an anticancer drug. Curcumin restrains cancer cell progression via telomerase activity suppression. However, the exact mechanism is still unknown. In this study, we demonstrate that the effects of curcumin on cell viability and telomerase activity can be blunted by reactive oxygen species (ROS) inhibitor N-acetyl cysteine (NAC). The ROS induced by curcumin in A549 cells was detected by flow cytometry. Using Western blot and RT-PCR, human telomerase reverse transcriptase (hTERT) decreased in the presence of curcumin. Sp1 is one of the important transcription factors in hTERT expression. Our data showed that curcumin decreases the expression of Sp1 through proteasome pathway. In addition, NAC blunted the Sp1 reduction and hTERT downregulation by curcumin. Further, reporter assay and DNA affinity precipitation assay confirmed the influence of curcumin on Sp1 in hTERT regulation. This is the first study to demonstrate that curcumin induces ROS production resulting in Sp1 binding activity inhibition and hTERT downregulation.

Esophageal metastasis from occult lung cancer

A 66-year-old man with dysphagia was found to have a poorly differentiated esophageal carcinoma by incision biopsy. Following esophagectomy, reconstruction with a gastric tube was performed. Pathological examination and immunohisto-chemistry showed infiltration of adenocarcinoma cells with positive thyroid transcription factor 1-staining in the submucosal layer, which indicated metastatic esophageal carcinoma. Although no pulmonary lesion could be visualized by imaging or bronchoscopy, pulmonary origin was highly suspected as a result of positive thyroid transcription factor 1-staining. To the best of our knowledge, this is the first reported case of metastatic esophageal carcinoma from occult lung cancer (AJCC TNM stage TX).

Abstract 2944: Genome-wide transcriptional modulation screening in non-smoking female lung cancer in Taiwan

Lung cancer has become the leading cause of cancer death in Taiwan and in most countries. Although smoking has been the major risk factor for lung cancer, less than 20% smokers develop lung cancer. In Taiwan, only about 50% of lung cancer cases were related to smoking, while more than 90% lung cancer females were non-smokers. In this study, we collected gene expression microarrays to investigate the pathogenesis process. One hundred and twenty lung tumor samples and their normal counterparts from non-smoking females were collected from National Taiwan University Hospital and Taichung Veterans General Hospital. RNAs from 60 paired samples were examined using Affymetrix Human U133 plus2.0 microarray. Paired t-tests were used to identify differentially expressed genes between tumor and normal tissues. The preliminary results showed there were 791 differentially expressed genes (p-value &lt; 10−14). Ingenuity Pathway Analysis (IPA) was utilized for further functional and pathway analyses on these genes, and the axon guidance signaling pathway was the most significantly enriched pathway. Among genes in the axon guidance signaling pathway, SEMA5A was chosen for further investigation because it was the most significant down-regulated gene in tumor tissue. Its down-regulation was validated by both real-time PCR and immunohistochemistry (IHC). Furthermore, Kaplan-Meier survival analysis showed that patients with low SEMA5A expression had poor overall survival as compared to those who had high SEMA5A expression. This significant association was also observed in two published studies. Therefore, these results indicated that the SEMA5A may play an important role in the carcinogenesis and can be a potential prognosis biomarker for non-smoking lung cancer females in Taiwan.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2944.

Abstract 112: Concurrent analysis between copy number variation and gene expression of non-smoking lung cancer females in Taiwan

Although smoking has been proved to be an important factor for lung cancer, the etiology and molecular mechanisms of non-smoking female lung cancer remain unclear. We collected paired normal and tumor lung tissues from 44 female non-smoking lung cancer patients. Copy number variation and Gene expression profiles were analyzed by Affymetrix U133plus 2.0 expression arrays and Affymetrix SNP 6.0 single nucleotide polymorphism (SNP) arrays. The data from two platforms were integrated for concurrent analyses in order to elucidate the putative molecular mechanisms. We first identified the probes located at the same region of gene expression and copy number variation (CNV). Next, we calculated the Pearson correlation coefficient to assess the association between log intensity values of mRNA expression and the corresponding averaged intensity values of SNP probes in both tumor and normal tissues. Genes were then selected based on the following two criteria: (1) the difference in expression-SNP correlations between normal and tumor tissues &gt; 0.7, and (2) the absolute expression-SNP correlation of either normal or tumor &gt;0.3. The selected genes were further analyzed by Ingenuity Pathway Analysis (IPA) to explore the related pathways and networks. Results of IPA showed that mitochondrial dysfunction, IGF-1 signaling, and cell cycle: G1/S checkpoint regulation pathways were significantly dysregulated in tumor tissues. The associations between lung cancer and genomic alternations in these enriched pathways have been reported previously, such as overexpression of IGF1R in IGF-1 signaling pathway might resist EGFR inhibitors used in lung cancer treatment. In summary, with the integrated data of copy number variation and expression, the concurrent analyses help to dissect lung carcinogenesis of non-smoking lung cancer females in Taiwan.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 112.

Lack of Fas-pathway gene mutations in primary resected esophageal squamous cell carcinoma

BACKGROUND

The Fas system regulates a number of physiological and pathological processes of cell death. Many types of cancer cells are resistant to Fas-mediated apoptosis by several mechanisms, including mutations of the genes involved in Fas-mediated apoptosis. The present study aimed to detect Fas pathway gene alterations in primary resected esophageal squamous cell carcinoma (ESCC).

METHODS

Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were used to analyze the expression of Fas in 34 archival specimens from patients with primary resected ESCC. We then explored the possibility of mutations in the genes involved in the proximal pathway of Fas mediated apoptosis (Fas, FADD). We analyzed exon 9 (death domain) of the Fas gene and exon 1 (death effective domain) of the FADD gene for gene mutations in these 34 specimens by polymerase chain reaction and DNA sequencing.

RESULTS

Immunohistochemistry and RT-PCR revealed that Fas was expressed in all primary resected ESCC specimens analyzed. However, we did not detect any structural alterations in exon 9 of the Fas gene or exon 1 of the FADD gene.

CONCLUSIONS

Inhibition of Fas-mediated apoptosis may not be due to gene mutations in the critical exon 9 of the Fas gene and exon 1 of the FADD gene in esophageal squamous cell carcinoma.