Mark B. Orringer

Somatic mutations affect key pathways in lung adenocarcinoma

Determining the genetic basis of cancer requires comprehensive analyses of large collections of histopathologically well-classified primary tumours. Here we report the results of a collaborative study to discover somatic mutations in 188 human lung adenocarcinomas. DNA sequencing of 623 genes with known or potential relationships to cancer revealed more than 1,000 somatic mutations across the samples. Our analysis identified 26 genes that are mutated at significantly high frequencies and thus are probably involved in carcinogenesis. The frequently mutated genes include tyrosine kinases, among them the EGFR homologue ERBB4; multiple ephrin receptor genes, notably EPHA3; vascular endothelial growth factor receptor KDR; and NTRK genes. These data provide evidence of somatic mutations in primary lung adenocarcinoma for several tumour suppressor genes involved in other cancers—including NF1, APC, RB1 and ATM—and for sequence changes in PTPRD as well as the frequently deleted gene LRP1B. The observed mutational profiles correlate with clinical features, smoking status and DNA repair defects. These results are reinforced by data integration including single nucleotide polymorphism array and gene expression array. Our findings shed further light on several important signalling pathways involved in lung adenocarcinoma, and suggest new molecular targets for treatment.

RANDOMIZED TRIAL OF PREOPERATIVE CHEMORADIATION VERSUS SURGERY ALONE IN PATIENTS WITH LOCOREGIONAL ESOPHAGEAL CARCINOMA

PURPOSE A pilot study of 43 patients with potentially resectable esophageal carcinoma treated with an intensive regimen of preoperative chemoradiation with cisplatin, fluorouracil, and vinblastine before surgery showed a median survival of 29 months in comparison with the 12-month median survival of 100 historical controls treated with surgery alone at the same institution. We designed a randomized trial to compare survival for patients treated with this preoperative chemoradiation regimen versus surgery alone. MATERIALS AND METHODS One hundred patients with esophageal carcinoma were randomized to receive either surgery alone (arm I) or preoperative chemoradiation (arm II) with cisplatin 20 mg/m2/d on days 1 through 5 and 17 through 21, fluorouracil 300 mg/m2/d on days 1 through 21, and vinblastine 1 mg/m2/d on days 1 through 4 and 17 through 20. Radiotherapy consisted of 1.5-Gy fractions twice daily, Monday through Friday over 21 days, to a total dose of 45 Gy. Transhiatal esophagectomy with a cervical esophagogastric anastomosis was performed on approximately day 42. RESULTS At median follow-up of 8.2 years, there is no significant difference in survival between the treatment arms. Median survival is 17.6 months in arm I and 16.9 months in arm II. Survival at 3 years was 16% in arm I and 30% in arm II (P = .15). This study was statistically powered to detect a relatively large increase in median survival from 1 year to 2.2 years, with at least 80% power. CONCLUSION This randomized trial of preoperative chemoradiation versus surgery alone for patients with potentially resectable esophageal carcinoma did not demonstrate a statistically significant survival difference.

Characterizing the cancer genome in lung adenocarcinoma

Somatic alterations in cellular DNA underlie almost all human cancers. The prospect of targeted therapies and the development of high-resolution, genome-wide approaches are now spurring systematic efforts to characterize cancer genomes. Here we report a large-scale project to characterize copy-number alterations in primary lung adenocarcinomas. By analysis of a large collection of tumours (n = 371) using dense single nucleotide polymorphism arrays, we identify a total of 57 significantly recurrent events. We find that 26 of 39 autosomal chromosome arms show consistent large-scale copy-number gain or loss, of which only a handful have been linked to a specific gene. We also identify 31 recurrent focal events, including 24 amplifications and 7 homozygous deletions. Only six of these focal events are currently associated with known mutations in lung carcinomas. The most common event, amplification of chromosome 14q13.3, is found in ∼12% of samples. On the basis of genomic and functional analyses, we identify NKX2-1 (NK2 homeobox 1, also called TITF1), which lies in the minimal 14q13.3 amplification interval and encodes a lineage-specific transcription factor, as a novel candidate proto-oncogene involved in a significant fraction of lung adenocarcinomas. More generally, our results indicate that many of the genes that are involved in lung adenocarcinoma remain to be discovered.

Discordant Protein and mRNA Expression in Lung Adenocarcinomas

The relationship between gene expression measured at the mRNA level and the corresponding protein level is not well characterized in human cancer. In this study, we compared mRNA and protein expression for a cohort of genes in the same lung adenocarcinomas. The abundance of 165 protein spots representing 98 individual genes was analyzed in 76 lung adenocarcinomas and nine non-neoplastic lung tissues using two-dimensional polyacrylamide gel electrophoresis. Specific polypeptides were identified using matrix-assisted laser desorption/ionization mass spectrometry. For the same 85 samples, mRNA levels were determined using oligonucleotide microarrays, allowing a comparative analysis of mRNA and protein expression among the 165 protein spots. Twenty-eight of the 165 protein spots (17%) or 21 of 98 genes (21.4%) had a statistically significant correlation between protein and mRNA expression (r > 0.2445; p < 0.05); however, among all 165 proteins the correlation coefficient values (r) ranged from −0.467 to 0.442. Correlation coefficient values were not related to protein abundance. Further, no significant correlation between mRNA and protein expression was found (r = −0.025) if the average levels of mRNA or protein among all samples were applied across the 165 protein spots (98 genes). The mRNA/protein correlation coefficient also varied among proteins with multiple isoforms, indicating potentially separate isoform-specific mechanisms for the regulation of protein abundance. Among the 21 genes with a significant correlation between mRNA and protein, five genes differed significantly between stage I and stage III lung adenocarcinomas. Using a quantitative analysis of mRNA and protein expression within the same lung adenocarcinomas, we showed that only a subset of the proteins exhibited a significant correlation with mRNA abundance.

Two Thousand Transhiatal Esophagectomies Changing Trends, Lessons Learned

Objective:“Rediscovered” in 1976, transhiatal esophagectomy (THE) has been applicable in most situations requiring esophageal resection and reconstruction. The objective of this study was to review the authors’ 30-year experience with THE and changing trends in its use. Methods:Using the authors’ prospective Esophagectomy Database, this single institution experience with THE was analyzed retrospectively. Results:Two thousand and seven THEs were performed—1063 (previously reported) between 1976 and 1998 (group I) and 944 from 1998 to 2006 (group II), 24% for benign disease, 76%, cancer. THE was possible in 98%. Stomach was the esophageal substitute in 97%. Comparing outcomes between group I and group II, statistically significant differences (P < 0.001) were observed in hospital mortality (4% vs. 1%); adenocarcinoma histology (69% vs. 86%); use of neoadjuvant chemoradiation (28% vs. 52%); mean blood loss (677 vs. 368 mL); anastomotic leak (14% vs. 9%); and discharge within 10 days (52% vs. 78%). Major complications remain infrequent: wound infection/dehiscence, 3%, atelectasis/pneumonia, 2%, intrathoracic hemorrhage, recurrent laryngeal nerve paralysis, chylothorax, and tracheal laceration, <1% each. Late functional results have been good or excellent in 73%. Aggressive preoperative conditioning, avoiding the ICU, improved pain management, and early ambulation reduce length of stay, with 50% in group II discharged within 1 week. Conclusion:THE refinements have reduced the historic morbidity and mortality of esophageal resection. This largest reported THE experience reinforces the value of consistent technique and a clinical pathway in managing these high acuity esophageal patients.

Preoperative chemoradiation followed by transhiatal esophagectomy for carcinoma of the esophagus: final report.

PURPOSE In 1990 we published the results of an intensive 3-week preoperative chemoradiation regimen for locoregional esophageal cancer that suggested improved survival compared with historical controls. We now report the long-term results at a median follow-up of 78.7 months. PATIENTS AND METHODS Forty-three patients with locoregional squamous cell carcinoma or adenocarcinoma of the esophagus or cardia were treated with fluorouracil (5-FU), cisplatin, and bolus vinblastine concurrent with radiation administered over 21 days. Transhiatal esophagectomy was performed on day 42. RESULTS Forty-one patients (95%) completed the preoperative treatment, and 36 (84%) had a potentially curative resection. Ten of 41 (24%) had no tumor in the resected esophagus and nodal tissues (path-negative group). The median survival duration of all 43 patients registered on study was 29 months; 34% were alive at 5 years. By histology, median survival durations were 32 months for 21 adenocarcinoma patients and 23 months for 22 squamous cell patients, with corresponding 5-year survival rates of 34% and 31%, respectively. Analysis of the 36 patients who underwent a potentially curative resection demonstrated median survival durations of 32 and 44 months and 5-year survival rates of 36% and 43%, respectively, for adenocarcinoma and squamous cell histologies. Path-negative (complete response [CR]) patients had a median survival duration of 70 months and 60% were alive at 5 years, while those patients with residual tumor in the resected esophagus had a median survival duration of 26 months and 32% were alive at 5 years (P = .114 by the log-rank test and P = .04 by the Wilcoxon test). CONCLUSION The results of this regimen appear improved over those reported with surgery alone, with an approximate doubling of the 5-year survival rate. Thirty-two percent of patients with residual tumor in the esophageal specimen are long-term survivors, which suggests a benefit from esophagectomy. A randomized trial is in progress to compare this preoperative regimen with immediate surgery.

Eliminating the cervical esophagogastric anastomotic leak with a side-to-side stapled anastomosis.

BACKGROUND Although the acute postoperative complications of a cervical esophagogastric anastomosis are less than those with an intrathoracic esophageal anastomosis, the long-term sequelae of a cervical anastomotic leak are not as minor as initially reported. Nearly 50% of cervical anastomotic leaks result in an anastomotic stricture, and the subsequent need for chronic dilatations negates the merits of an operation intended to restore comfortable swallowing. OBJECTIVE This study was undertaken to determine whether construction of a side-to-side stapled cervical esophagogastric anastomosis after transhiatal esophagectomy could reliably eliminate the majority of anastomotic leaks. METHODS In 114 consecutive patients undergoing transhiatal esophagectomy, a functional side-to-side cervical esophagogastric anastomosis was constructed with the Auto Suture Endo-GIA II stapler (United States Surgical Corporation, Auto Suture Company Division, Norwalk, Conn) applied directly through the cervical wound. This side-to-side stapled anastomosis has 3 rows of staples. Early postoperative anastomotic morbidity, subsequent need for anastomotic dilatations, and patient satisfaction with swallowing were evaluated. RESULTS Before the side-to-side stapled anastomosis, the incidence of cervical esophagogastric anastomosis leak in over 1000 patients undergoing transhiatal esophagectomy having a manually sewn anastomosis varied from 10% to 15%. Among the 111 survivors of transhiatal esophagectomy and a side-to-side stapled anastomosis, there were 3 (2.7%) clinically significant anastomotic leaks. This lowered incidence of leaks has contributed to reduction in the average length of stay after an uncomplicated transhiatal esophagectomy to 7 days and has provided more comfortable swallowing, ease of subsequent esophageal dilatations, and greater patient satisfaction. CONCLUSIONS Construction of the cervical esophagogastric anastomosis with a side-to-side stapled anastomosis greatly reduces the frequency of anastomotic leaks and later strictures. The side-to-side stapled anastomosis is a major technical advance in the progression of refinements of transhiatal esophagectomy and a cervical esophagogastric anastomosis.

Transhiatal esophagectomy without thoracotomy for carcinoma of the thoracic esophagus.

Transhiatal esophagectomy (THE) without thoracotomy was performed in 100 patients with carcinoma of the thoracic esophagus (7 upper, 45 mid, and 48 lower third). The esophagus was replaced with stomach (96) or colon (4). Intraoperative complications included pneumothorax requiring a chest tube(s) (63) and membranous tracheal tear (2). Blood loss averaged 880 ml. Postoperative complications included transient recurrent laryngeal nerve paresis (31), anastomotic leak (5), and chylothorax (2). There were no intraoperative deaths or re-explorations for postoperative bleeding. Six hospital deaths resulted from aspiration pneumonia (2), retroperitoneal or mediastinal abscess (2), pulmonary embolus (1), and respiratory insufficiency (1). Postoperative hospitalization averaged 14 days. Actuarial survival among the 94 operative survivors is 82% at 6 months, 52% at 12 months, 32% at 24 months, 22% at 36 months, and 17% at 48 months. Of the operative survivors, 15% have lived 2 years or more and 10% are clinically disease free. THE is safe, associated with a low morbidity, and achieves excellent palliation and survival at least as good as that reported in many series of transthoracic esophagectomies for esophageal carcinoma.

Protein profiles associated with survival in lung adenocarcinoma

Morphologic assessment of lung tumors is informative but insufficient to adequately predict patient outcome. We previously identified transcriptional profiles that predict patient survival, and here we identify proteins associated with patient survival in lung adenocarcinoma. A total of 682 individual protein spots were quantified in 90 lung adenocarcinomas by using quantitative two-dimensional polyacrylamide gel electrophoresis analysis. A leave-one-out cross-validation procedure using the top 20 survival-associated proteins identified by Cox modeling indicated that protein profiles as a whole can predict survival in stage I tumor patients (P = 0.01). Thirty-three of 46 survival-associated proteins were identified by using mass spectrometry. Expression of 12 candidate proteins was confirmed as tumor-derived with immunohistochemical analysis and tissue microarrays. Oligonucleotide microarray results from both the same tumors and from an independent study showed mRNAs associated with survival for 11 of 27 encoded genes. Combined analysis of protein and mRNA data revealed 11 components of the glycolysis pathway as associated with poor survival. Among these candidates, phosphoglycerate kinase 1 was associated with survival in the protein study, in both mRNA studies and in an independent validation set of 117 adenocarcinomas and squamous lung tumors using tissue microarrays. Elevated levels of phosphoglycerate kinase 1 in the serum were also significantly correlated with poor outcome in a validation set of 107 patients with lung adenocarcinomas using ELISA analysis. These studies identify new prognostic biomarkers and indicate that protein expression profiles can predict the outcome of patients with early-stage lung cancer.

Descending necrotizing mediastinitis: Transcervical drainage is not enough

One of the most lethal forms of mediastinitis is descending necrotizing mediastinitis, in which infection arising from the oropharynx spreads to the mediastinum. Two recently treated patients are reported, and the English-language literature on this disease is reviewed from 1960 to the present. Despite the development of computed tomographic scanning to aid in the early diagnosis of mediastinitis, the mortality for descending necrotizing mediastinitis has not changed over the past 30 years, in large part because of continued dependence on transcervical mediastinal drainage. Although transcervical drainage is usually effective in the treatment of acute mediastinitis due to a cervical esophageal perforation, this approach in the patient with descending necrotizing mediastinitis fails to provide adequate drainage and predisposes to sepsis and a poor outcome. In addition to cervical drainage, aggressive, early mediastinal exploration--debridement and drainage through a subxiphoid incision or thoracotomy--is advocated to salvage the patient with descending necrotizing mediastinitis.