ABSTRACT
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.
ABSTRACT
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.