Aberrant Promoter Hypermethylation of p16 and RASSF1a Genes in Colorectal Cancer - Significance in Young Patients.

OBJECTIVE: The clinical profile of colorectal cancers (CRC) in India is different from that described in western countries. Microsatellite instability and APC mutation explain the molecular biology of up to 50% of colorectal cancers. Global genome hypermethylation may be the cause in at least 20% of cases. Few studies from India have examined the epigenetic profile of colorectal cancers. This study was designed to study aberrant promoter hypermethylation of two select tumour suppressor genes (p16, RASSF1a) in patients with colorectal cancer and their association with clinicopathologic features. METHODS: A total of 41 samples including controls were collected from colorectal cancer patients. DNA was isolated from tumour tissue, and methylation-specific PCR was performed for the 2 genes. RESULTS: p16 and RASSF1a promoter hypermethylation was found in 26% and 48% of CRC cases, respectively. RASSF1a promoter hypermethylation was more often seen in young CRC patients aged 40 years or less, and this was found to be statistically significant (p value = 0.037). CONCLUSION: RASSF1a hypermethylation is peculiar to rectal cancers and left-sided colonic tumours in young patients. Large-scale population-based studies with extensive genetic and epigenetic characterization are required for a better understanding and further validation of our findings. For individuals diagnosed with sporadic CRC, these studies on specimen might help predict prognosis and response to therapy.

Effect of Preoperative Biliary Stenting on Outcomes of Pancreaticoduodenectomy.

Biliary drainage before pancreaticoduodenectomy was introduced to decrease morbidity from obstructive jaundice. Recent retrospective and randomised data show that preoperative biliary drainage (PBD) increases perioperative infectious complications. Most patients presenting to our tertiary care centre have undergone drainage procedures prior to surgical consultation. We analysed the impact of PBD, specifically endoscopic stent placement, on the postoperative outcome of pancreaticoduodenectomy at our centre. A cohort of 87 patients undergoing pancreaticoduodenectomy from 2012 to 2016 was identified. Data was collected retrospectively and a comparative analysis of stented and nonstented patients was done. Comparison of the 23 stented patients was done with 23 nonstented patients after matching them for age, sex and bilirubin levels. Median total bilirubin level in stented patients was 10.2 mg/dl versus 7.7 mg/dl in nonstented patients. The infectious complication rate in the stented group was 39.1% versus 12.7% in the nonstented group (P value < 0.05). There was no difference in the anastomotic leak rate between the two groups. Time to curative surgery in the stented group was significantly more than in the nonstented group. Stented patients are at a higher risk for postoperative infectious complications. Patients with obstructive jaundice awaiting surgery should undergo selective biliary drainage after careful planning and discussion between the operating surgeon and the endoscopist.

Perioperative Artificial Enteral Nutrition in Malnourished Esophageal and Stomach Cancer Patients and Its Impact on Postoperative Complications.

Cancer is responsible for approximately 13% of all causes of death worldwide, and 20% of cancer patients die because of malnutrition and its complications. Malnutrition is common in cancer of stomach and esophagus. Although it is widely accepted that malnutrition adversely affects the postoperative outcome of patients, there is little evidence that perioperative nutrition support can reduce surgical risk in malnourished cancer patients. This prospective study was carried out from December 2016 to July 2017 at the Kidwai Memorial Institute of Oncology, Bengaluru. After stratified for age, sex, and tumor localization, patients were selected non-randomly and assigned to study (n = 30, 14 women, 16 men) and control group (n = 30, 14 women, 16 men) as alternate patients. Within 48 h of admission, patients underwent nutritional assessment by the subjective global assessment. Perioperative nutrition was administered in the study group by enteral route only. Patients had a functioning gastrointestinal tract, and they received enteral nutrition (EN). Target intake of non-protein (25 kcal/kg per day) and protein (0.25 g nitrogen/kg per day) was provided using available enteral formulas. This was supplementary to standard hospital diet. Nutritional re-assessment after 15 days of intervention showed significant change in nutritional status, which was measured as gain in weight for each patient. There were significant differences in the mortality and complications between the two groups. The total length of hospitalization and postoperative stay of the control patients were significantly longer than those of the study patients. In conclusion, perioperative nutrition support can decrease the incidence of postoperative complications in moderately and severely malnourished gastric and esophageal cancer patients. In addition, it is effective in reducing mortality. Enteral nutrition support alone can be used in the management of malnourished patients undergoing gastric and esophageal surgery.

Breast Cancer with Synchronous Renal Cell Carcinoma: A Rare Presentation.

Primary cancer arising from multiple organs is a well known fact. Synchronous tumours have been most commonly associated with kidney cancer. Bladder, prostate, colorectal and lung cancer are the most common synchronous primaries with Renal Cell Carcinoma (RCC) identified till date. We found metachronous tumours of breast with RCC in literature search which included both metastatic tumours as well second primaries. Overall, 25 cases of metastatic breast tumours and eight cases of second primary in previously treated RCC have been reported in the literature. Here, we are reporting a case of synchronous presentation of carcinoma breast with RCC which is very rare because most of the multiple malignancies reported in the literature are metastatic tumours or metachronous breast malignancy with RCC.

"Ovarian Metastases from Colorectal Cancer: Our Experience".

Ovarian metastases from colorectal cancer are uncommon and can present synchronously and metachronoulsy. Role of prophylactic oophorectomy for colorectal cancer is controversial and there is no definitive evidence to support it. A retrospective analysis of all the patients with colorectal cancer who had attended a single unit at our center have been analysed. Clinical presentation, Pathological features and image findings were analyzed. We had 7 patients with ovarian metastases who had presented synchronously or metachronously at our institute. Five patients presented synchronously at the time of primary surgery and 2 patients had presented metachronously after the treatment of primary. Three patients had malignancy in ascending colon and 2 had in sigmoid colon , one in rectosigmoid junction and one case in rectum. The mean overall survival rate was 12.4 months (range 6-20 months). All the patients received adjuvant chemotherapy. Ovarian metastases is rare in colorectal and occurs in younger patients.

Calcium calmodulin dependent kinase kinase 2 - a novel therapeutic target for gastric adenocarcinoma.

Gastric cancer is one of the most common gastrointestinal malignancies and is associated with poor prognosis. Exploring alterations in the proteomic landscape of gastric cancer is likely to provide potential biomarkers for early detection and molecules for targeted therapeutic intervention. Using iTRAQ-based quantitative proteomic analysis, we identified 22 proteins that were overexpressed and 17 proteins that were downregulated in gastric tumor tissues as compared to the adjacent normal tissue. Calcium/calmodulin-dependent protein kinase kinase 2 (CAMKK2) was found to be 7-fold overexpressed in gastric tumor tissues. Immunohistochemical labeling of tumor tissue microarrays for validation of CAMKK2 overexpression revealed that it was indeed overexpressed in 94% (92 of 98) of gastric cancer cases. Silencing of CAMKK2 using siRNA significantly reduced cell proliferation, colony formation and invasion of gastric cancer cells. Our results demonstrate that CAMKK2 signals in gastric cancer through AMPK activation and suggest that CAMKK2 could be a novel therapeutic target in gastric cancer.

Evaluation of protein expression pattern of stanniocalcin 2, insulin-like growth factor-binding protein 7, inhibin beta A and four and a half LIM domains 1 in esophageal squamous cell carcinoma.

The pathogenesis of esophageal squamous cell carcinoma (ESCC) involves both genetic and environmental factors. Previously, we have carried out gene and protein expression profiling of ESCC using DNA microarrays and mass spectrometry-based quantitative proteomics, respectively. These studies resulted in identification of several potential biomarkers of ESCC, some with known reports of differential expression in the scientific literature and others that were novel observations from our studies. We report systematic validation of selected markers from our studies on a larger cohort of cancer tissue sections by immunohistochemical labeling of tissue microarrays. We have validated expression of insulin-like growth factor-binding protein 7 (IGFBP7), stanniocalcin 2 (STC2), inhibin beta A (INHBA) and four and a half LIM domains 1 (FHL1). Immunohistochemical labeling with anti-stanniocalcin 2 antibody demonstrated its overexpression in 132/140 (94%) cases, IGFBP7 showed overexpression in 127/140 (91%) cases and overexpression of INHBA was observed in 62/105 (59%) of ESCC cases. In contrast, FHL1 expression was observed only in 12/143 (8%) of ESCC cases suggesting its possible involvement in tumor suppression. These data suggest that IGFBP7, INHBA, STC2 and FHL1 might play an important role in ESCC tumorigenesis, which can be explored in future studies. Overall, our findings open up new avenues for development of novel therapeutics and/or diagnostic approaches in ESCC.

Overexpression of periostin and lumican in esophageal squamous cell carcinoma.

To identify biomarkers for early detection for esophageal squamous cell carcinoma (ESCC), we previously carried out a genome-wide gene expression profiling study using an oligonucleotide microarray platform. This analysis led to identification of several transcripts that were significantly upregulated in ESCC compared to the adjacent normal epithelium. In the current study, we performed immunohistochemical analyses of protein products for two candidates genes identified from the DNA microarray analysis, periostin (POSTN) and lumican (LUM), using tissue microarrays. Increased expression of both periostin and lumican was observed in 100% of 137 different ESCC samples arrayed on tissue microarrays. Increased expression of periostin and lumican was observed in carcinoma as well as in stromal cell in the large majority of cases. These findings suggest that these candidates can be investigated in the sera of ESCC patients using ELISA or multiple reaction monitoring (MRM) type assays to further explore their utility as biomarkers.

Genomewide mRNA profiling of esophageal squamous cell carcinoma for identification of cancer biomarkers.

Cancer of the esophagus is of two main types, each with distinct etiological and pathological characteristics. Esophageal squamous cell carcinoma (ESCC) is predominant type of esophageal cancers worldwide comprising almost 95% of cases. While ESCC is prevalent in the developing world, esophageal adenocarcinoma is commonly seen in the developed country, usually in association with Barrett's esophagus. In spite of its higher prevalence, ESCC has not been studied as intensively as esophageal adenocarcinoma. ESCC and esophageal adenocarcinoma are common cancers worldwide with poor survival rate among patients mainly because both of these cancers lack early biomarkers of identification. Molecular mechanisms contributing to initiation and progression of esophageal squamous cell carcinoma are still poorly understood. Development of DNA microarray technology allows high-throughput identification of gene expression profiles in cancers. In order to identify molecules as candidates for early diagnosis and/or as therapeutic targets, we analyzed the mRNA expression profiles of 20 cases of ESCC using whole genome DNA microarrays. A total of 2,235 genes were differentially regulated in the tumors as compared to the corresponding adjacent normal epithelium of which 881 were significantly upregulated. We validated two molecules that were not previously reported to be overexpressed in ESCC, oral cancer overexpressed 2 (ORAOV2) and fibroblast activation protein (FAP), by immunohistochemical labeling of tissue microarrays and archival tissue sections and found that they were overexpressed in 98% (116/118) and 68% (79/116) of cases, respectively. By gene enrichment analysis, we identified significant downregulation of several genes in the arachidonic acid metabolic pathway. Overall, using this approach we have identified a number of promising novel candidates that can be validated further for their potential to serve as biomarkers for ESCC.