Giovanni Corso

Gastrointestinal Adenocarcinomas of the Esophagus, Stomach, and Colon Exhibit Distinct Patterns of Genome Instability and Oncogenesis

A more detailed understanding of the somatic genetic events that drive gastrointestinal adenocarcinomas is necessary to improve diagnosis and therapy. Using data from high-density genomic profiling arrays, we conducted an analysis of somatic copy-number aberrations in 486 gastrointestinal adenocarcinomas including 296 esophageal and gastric cancers. Focal amplifications were substantially more prevalent in gastric/esophageal adenocarcinomas than colorectal tumors. We identified 64 regions of significant recurrent amplification and deletion, some shared and others unique to the adenocarcinoma types examined. Amplified genes were noted in 37% of gastric/esophageal tumors, including in therapeutically targetable kinases such as ERBB2, FGFR1, FGFR2, EGFR, and MET, suggesting the potential use of genomic amplifications as biomarkers to guide therapy of gastric and esophageal cancers where targeted therapeutics have been less developed compared with colorectal cancers. Amplified loci implicated genes with known involvement in carcinogenesis but also pointed to regions harboring potentially novel cancer genes, including a recurrent deletion found in 15% of esophageal tumors where the Runt transcription factor subunit RUNX1 was implicated, including by functional experiments in tissue culture. Together, our results defined genomic features that were common and distinct to various gut-derived adenocarcinomas, potentially informing novel opportunities for targeted therapeutic interventions.

Hereditary Diffuse Gastric Cancer Syndrome: CDH1 Mutations and Beyond

IMPORTANCE E-cadherin (CDH1) is a cancer predisposition gene mutated in families meeting clinically defined hereditary diffuse gastric cancer (HDGC). Reliable estimates of cancer risk and spectrum in germline mutation carriers are essential for management. For families without CDH1 mutations, genetic-based risk stratification has not been possible, resulting in limited clinical options. OBJECTIVES To derive accurate estimates of gastric and breast cancer risks in CDH1 mutation carriers and determine if germline mutations in other genes are associated with HDGC. DESIGN, SETTING, AND PARTICIPANTS Testing for CDH1 germline mutations was performed on 183 index cases meeting clinical criteria for HDGC. Penetrance was derived from 75 mutation-positive families from within this and other cohorts, comprising 3858 probands (353 with gastric cancer and 89 with breast cancer). Germline DNA from 144 HDGC probands lacking CDH1 mutations was screened using multiplexed targeted sequencing for 55 cancer-associated genes. MAIN OUTCOMES AND MEASURES Accurate estimates of gastric and breast cancer risks in CDH1 mutation carriers and the relative contribution of other cancer predisposition genes in familial gastric cancers. RESULTS Thirty-one distinct pathogenic CDH1 mutations (14 novel) were identified in 34 of 183 index cases (19%). By the age of 80 years, the cumulative incidence of gastric cancer was 70% (95% CI, 59%-80%) for males and 56% (95% CI, 44%-69%) for females, and the risk of breast cancer for females was 42% (95% CI, 23%-68%). In CDH1 mutation-negative index cases, candidate mutations were identified in 16 of 144 probands (11%), including mutations within genes of high and moderate penetrance: CTNNA1, BRCA2, STK11, SDHB, PRSS1, ATM, MSR1, and PALB2. CONCLUSIONS AND RELEVANCE This is the largest reported series of CDH1 mutation carriers, providing more precise estimates of age-associated risks of gastric and breast cancer that will improve counseling of unaffected carriers. In HDGC families lacking CDH1 mutations, testing of CTNNA1 and other tumor suppressor genes should be considered. Clinically defined HDGC families can harbor mutations in genes (ie, BRCA2) with different clinical ramifications from CDH1. Therefore, we propose that HDGC syndrome may be best defined by mutations in CDH1 and closely related genes, rather than through clinical criteria that capture families with heterogeneous susceptibility profiles.

Germline CDH1 deletions in hereditary diffuse gastric cancer families

Germline CDH1 point or small frameshift mutations can be identified in 30–50% of hereditary diffuse gastric cancer (HDGC) families. We hypothesized that CDH1 genomic rearrangements would be found in HDGC and identified 160 families with either two gastric cancers in first-degree relatives and with at least one diffuse gastric cancer (DGC) diagnosed before age 50, or three or more DGC in close relatives diagnosed at any age. Sixty-seven carried germline CDH1 point or small frameshift mutations. We screened germline DNA from the 93 mutation negative probands for large genomic rearrangements by Multiplex Ligation-Dependent Probe Amplification. Potential deletions were validated by RT–PCR and breakpoints cloned using a combination of oligo-CGH-arrays and long-range-PCR. In-silico analysis of the CDH1 locus was used to determine a potential mechanism for these rearrangements. Six of 93 (6.5%) previously described mutation negative HDGC probands, from low GC incidence populations (UK and North America), carried genomic deletions (UK and North America). Two families carried an identical deletion spanning 193 593 bp, encompassing the full CDH3 sequence and CDH1 exons 1 and 2. Other deletions affecting exons 1, 2, 15 and/or 16 were identified. The statistically significant over-representation of Alus around breakpoints indicates it as a likely mechanism for these deletions. When all mutations and deletions are considered, the overall frequency of CDH1 alterations in HDGC is ∼46% (73/160). CDH1 large deletions occur in 4% of HDGC families by mechanisms involving mainly non-allelic homologous recombination in Alu repeat sequences. As the finding of pathogenic CDH1 mutations is useful for management of HDGC families, screening for deletions should be offered to at-risk families.

Somatic Mutations and Deletions of the E-Cadherin Gene Predict Poor Survival of Patients With Gastric Cancer

PURPOSE The prognosis of gastric cancer (GC) is poor, and the molecular pathogenesis players are vastly unknown. Surgery remains the primary option in GC treatment. The aim of this study was to investigate the impact of somatic CDH1 alterations in prognosis and survival of patients with GC. PATIENTS AND METHODS A series of patients with sporadic and familial GC (diffuse and intestinal; n = 246) were analyzed for somatic CDH1 mutations, promoter hypermethylation, and loss of heterozygosity (LOH) by polymerase chain reaction sequencing. E-cadherin protein expression was determined by immunohistochemistry. Associations between molecular, clinicopathologic, and survival data were analyzed. RESULTS CDH1 somatic alterations were found in approximately 30% of all patients with GC. Both histologic types of sporadic GC displayed LOH in 7.5%, mutations in 1.7%, and hypermethylation in 18.4% of patients. Primary tumors from hereditary diffuse GC, lacking germline CDH1 alterations, showed exclusively CDH1 promoter hypermethylation in 50% of patients. Familial intestinal GC (FIGC) tumors showed LOH in 9.4% and hypermethylation in 17.0%. CDH1 alterations did not associate with a particular pattern of E-cadherin expression. Importantly, the worst patient survival rate among all GCs analyzed was seen in patients with tumors carrying CDH1 structural alterations, preferentially those belonging to FIGC families. CONCLUSION CDH1 somatic alterations exist in all clinical settings and histotypes of GC and associate with different survival rates. Their screening at GC diagnosis may predict patient prognosis and is likely to improve management of patients with this disease.

Complications after Extended (D2) and Superextended (D3) Lymphadenectomy for Gastric Cancer: Analysis of Potential Risk Factors

BackgroundVery few studies from Western centers have compared D2 and D3 dissection in the surgical treatment of gastric cancer. The aim of the prospective observational study reported here was to analyze the postoperative outcome and potential risk factors for complications following D2 and D3 lymphadenectomy.MethodsA total of 330 consecutive patients, of which 251 submitted to D2 lymphadenectomy and 79 were treated by D3 lymphadenectomy, were enrolled in the study. Twenty potential risk factors for morbidity and mortality were studied by means of univariate and multivariate analysis.ResultsOverall morbidity and mortality rates were 34% (111 patients) and 4% (14 patients), respectively. Abdominal abscess, anastomotic leakage, pleuropulmonary diseases and pancreatitis were the most commonly observed complications. No differences in morbidity, surgical morbidity, mortality rates and mean hospital stay between D2 and D3 lymphadenectomy were found. Multivariate analysis revealed that American Society of Anesthesiologists’ (ASA) class II/III versus class I, perioperative blood transfusions, and low albumin serum levels were independent predictors of postoperative complications. Age, surgical radicality (R1/R2 vs. R0) and low albumin serum levels independently predicted mortality. Mortality rate was .5% in the 203 patients aged 75 years or younger who underwent curative surgery. Most of deaths were observed in patients older than 75 years with low albumin serum levels or treated by non-curative surgery.ConclusionsD2 lymphadenectomy represents a feasible procedure associated to acceptable morbidity and mortality rates. In specialized centers, D3 lymphadenectomy may be performed without increasing the risk of postoperative complications and associated deaths in carefully selected patients. These techniques should be avoided in subgroups of patients with a high risk of postoperative mortality.

Safety and Potential Benefit of Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Peritoneal Carcinomatosis From Primary or Recurrent Ovarian Cancer

To analyze the outcomes of cytoreductive surgery and HIPEC in patients with peritoneal carcinomatosis from ovarian cancer.

Perforated gastric carcinoma: a report of 10 cases and review of the literature.

BackgroundPerforation is a rare complication of gastric carcinoma, accounting for less than 1% of all gastric cancer cases. The aim of the present study is to evaluate the prognostic value of perforation and to point out the surgical treatment options.MethodsA total of 10 patients with perforated gastric carcinoma were retrospectively reviewed among 2564 consecutive cases of gastric cancer operated in three Centers belonging to the Italian Research Group for Gastric Cancer. The clinicopathological features including tumor stage and survival were analyzed and compared to literature data.ResultsIncidence rate was 0.39%. All patients underwent emergency surgery, being performed gastrectomy in 6 patients (mortality 17%) and repair surgery in 4 patients (mortality 75%). The survival of patients was related to the stage of the disease, with 2 long-survival cases.ConclusionPerforation usually occurs in advanced stages of gastric cancer; nevertheless surgeons should not be always discouraged from a radical treatment of perforated gastric cancer, since perforation even occurs in early stages and seems not to be a negative prognostic factor itself. When possible, emergency gastrectomy should be performed, leaving repair surgery for unresectable tumors. A two-stage treatment is a good treatment option for frail patients with resectable tumors.

Super-extended (D3) lymphadenectomy in advanced gastric cancer

PURPOSE To analyze our experience with D3 lymphadenectomy in the treatment of advanced GC with specific reference to post-operative morbidity and mortality, incidence of para-aortic node (PAN) metastases, and long-term prognosis. METHODS Short- and long-term results of D3 lymphadenectomy were analyzed in 286 patients with advanced GC. RESULTS PAN metastases were demonstrated in 37 patients. PAN involvement was significantly higher in upper third tumours (29%) compared to middle and lower third (7%; P < 0.001). Eighty patients developed post-operative complications, being pulmonary disorders (6%), abdominal abscesses (4.5%) and pancreatic fistulas (3%) the most frequently observed. In-hospital mortality was 2%. Overall 5-year survival rate for R0 pT2-4 patients was 52%. When considering survival in relation to nodal involvement, both pN3 and non-regional lymph node metastases (M1a) patients showed a chance of long-term survival: 5-year survival was 31% for pN3 and 17% for M1a cases. Furthermore, the 5-year survival rate was remarkably high (about 60%) even in pN2 and pN3 subsets when no serosal invasion (pT2) was demonstrated. CONCLUSIONS D3 lymphadenectomy could be further explored in specialized centers for curative surgery of advanced GC, especially for upper third tumours, providing that an acceptable morbidity and no increase in mortality can be offered.

E-cadherin genetic screening and clinico-pathologic characteristics of early onset gastric cancer

AIM CDH1 germline alterations occur in about 40% of hereditary diffuse gastric cancer (HDGC) families. CDH1 germline mutations are also documented in few early onset diffuse gastric cancer patients (EODGC) without family history, but the real frequency in this setting in unknown. In these patients, the advanced stage at the time of diagnosis remains a clinical burden due to the poor long term survival. METHODS The entire coding region and exon flanking sequences of the CDH1 gene was analysed by direct sequencing in 21 EODGC patients aged ≤50 years. The potential deleterious nature for a new CDH1 missense variant was assessed by cell-cell aggregation and invasion assays. Somatic CDH1 mutation, loss of heterozygosity (LOH) and promoter hypermethylation was explored in the tumour from one CDH1 germline mutation carrier. RESULTS Two novel CDH1 germline variants were identified in 21 EODGC cases, c.670C>T and -63C>A. Functional analysis of the c.670C>T missense variant classified this mutation as non-pathogenic. The analysis of CDH1 somatic second hits failed to demonstrate E-cadherin structural and epigenetic alterations in the tumour sample. CONCLUSION Data from the present work and a systematic review of the literature revealed that CDH1 germline mutations occurred in 7.2% of EOGC patients invariably with diffuse of mixed histology. From these, proved CDH1 mutation pathogenicity has been assigned only to 2.3% of the cases who were recurrently diagnosed before 35 years old. Germline CDH1 mutation remain the only germline genetic defect described in this type of patients and CDH1 mutation screening should be recommended for patients with these characteristics.

Postoperative Complications and Functional Results After Subtotal Gastrectomy with Billroth II Reconstruction for Primary Gastric Cancer

Subtotal gastrectomy is considered the preferred treatment for gastric cancer with antral location. The aim of this study was to assess the incidence of early postoperative complications and late functional results in patients who underwent subtotal gastrectomy with Billroth II reconstruction for primary gastric adenocarcinoma. The results of 310 patients were analyzed with regard to postoperative complications and death rates. Functional results as they relate to the gastric resection were evaluated in 195 disease-free patients. Of the 310 patients, 77 developed postoperative general and surgical complications (24.8%) and 13 consequently died (in-hospital mortality: 4.2%). Although infrequent (6 cases, 1.9%), anastomotic leak was the most serious complication (4 cases died during the postoperative phase). Considering functional results, weight loss continued for the first trimester after surgery, after which it stabilized. Loss of appetite was rarely observed; early after the operation the majority of patients were consuming a normal diet and regularly consumed less than five meals per day (83.6%). Dumping syndrome was uncommon and usually resolved within one year (12.3% at three months, 9.5% after one year, 5.2% after two years). On the other hand, postprandial abdominal fullness was frequently observed (43.1% at three months, 36.1% after one year, 21.3% after three years, and 16.5% after five years). Billroth II reconstruction after subtotal gastrectomy is associated with a limited risk of anastomotic complications. Anastomotic leak, although infrequent, is a life-threatening complaint and requires prompt recognition and aggressive surgical treatment. The incidence of late complications was low and the majority of patients recovered from them within one year after surgery, although the occurrence of postprandial abdominal fullness was not completely irrelevant.