The Learning Curve for Pancreaticoduodenectomy: The Experience of a Single Surgeon.

BACKGROUND AND AIMS: Pancreaticoduodenectomy (PD) is a complex and high-skill demanding procedure often associated with significant morbidity and mortality. However, the results have improved over the past two decades. However, there is a paucity of research concerning the learning curve for PD. Our aim was to report the outcomes of 100 consecutive PDs representing a single surgeon's learning curve and to depict the factors that influenced the learning process. METHODS: We reviewed the first 121 PDs performed at our academic center (2013-2019) by a single surgeon; 110 were PDs (5 laparoscopic and 105 open) and 11 were total PDs (1 laparoscopic and 10 open). Subsequent statistics was performed on the first 100 PDs, with attention paid to the learning curve and survival rate at 5 years. The data were analyzed comparing the first 50 cases (Group 1) to the last 50 cases (Group 2). RESULTS: The most frequent histopathological tumor type was pancreatic ductal adenocarcinoma (50%). A total of 39% of patients had preoperative biliary drainage and 45% presented with positive biliary cultures. The preferred reconstruction technique included pancreaticogastrostomy (99%), in situ hepaticojejunostomy (70%), and precolic gastro-jejunal anastomosis (88%). Postoperative complications included biliary fistula (1%), pancreatic fistula (8%), pancreatic stump bleeding (4%), and delayed gastric emptying (13%). The mean operative time decreased after the first 50 cases (p < 0.001) and blood loss after 60 cases (p = 0.046). R1 resections lowered after 25 cases (p = 0.025). Vascular resections (17%) did not influence the rate of complications (p = 0.8). The survival rate at 5 years for pancreatic adenocarcinoma was 32.93%. CONCLUSIONS: Outcomes improve as surgeon experience increases, with proper training being the most important factor for minimizing the impact of the learning curve over the postoperative complications. Analyzing the learning curve from the perspective of a single surgeon is mandatory for accurate statistical results and interpretation.

Detection of epithelial specific cell adhesion molecules in colon cancer and the correlation with clinical and pathological characteristics EpCAM expression in colon cancer.

AIM: The aim of this study was to evaluate the correlation between EpCAM expression in colon cancer tissue and the clinico-pathological characteristics of the patients. MATERIAL AND METHODS: This is a prospective, longitudinal, observational study on 80 patients undergoing for colon cancer between January - December 2017. EpCAM expression at tumoral level was analyzed in relation with clinical and pathological variables of the patients using anti-EpCAM specific antibody. RESULTS: EpCAM expression was predominant in tumoral tissue compared to normal colonic mucosa and most of the cases (58.7%) showed increased EpCAM expression. Although increased EpCAM expression was observed in advanced stages and in patients with advanced locoregional disease, there was no statistically significant correlation with the clinical and pathological characteristics of the patients. DISCUSSION: The majority of the analyzed samples showed increased EpCAM expression in tumoral tissue suggesting its involvement in the carcinogenesis process. Numerous studies have identified EpCAM overexpression in colon cancer as a negative prognostic factor, being associated with advanced stage of the disease and a poor prognosis of the patient but results are inconsistent. Nevertheless, assessing a possible correlation between EpCAM expression at tumoral level and clinico- pathological characteristics is dependent on the type of antibody used to identify the molecule of interest. CONCLUSIONS: EpCAM detection in colon cancer using anti-human CD326/EpCAM clone VU-1D9 does not allow the correlation between its expression and the clinico-pathological characteristics of the patients and it should only be used for EpCAM identification in colon cancer tissues. KEY WORDS: Cancer, Colon, EpCAM, Immunohistochemistry.

Predictors of 1-year postoperative mortality in radical colon cancer surgery.

AIM: The aim of this study was to determine the impact of patient, tumor and surgery-related parameters on 1-year postoperative mortality in a cohort of patients operated in a single tertiary center. MATERIALS AND METHODS: The study included 605 patients diagnosed with colon cancer between January 2013 and December 2015 that underwent radical surgery in a tertiary center. Patient demographics, comorbidities, preoperative biological parameters alongside with tumor and surgery-related factors were prospectively recorded and then analyzed in relation 1-year postoperative mortality. RESULTS: One-year mortality rate in the study group was 10.9%. Independent risk factors in relation to 1-year mortality were advanced TNM stage (OR 3.10, 1.10 - 8.75 95% CI ), emergency surgery (OR 1.91, 1.11 - 3.74 95% CI ), location of the tumor in the ascending colon (OR 2.17, 1.32 - 3.57 95% CI ), multiorgan resections (OR 2.07, 1.15 - 3.74 95% CI), age over 63 years (OR 2.05, 1.16 - 3.62 95% CI) and the history of alcohol consumption (OR 2.058, 1.17 - 3.61 95% CI ). DISCUSSION: Postoperative complications are still being reported in colon cancer surgery, despite technological progress and constant research in the field. So far, factors that influence postoperative mortality have been mostly studied up to 30 days postoperatively. According to some recent papers, reporting 30-day mortality data can underestimate accurate communication of postoperative adverse events. Thus, 1-year mortality in colon cancer surgery could be a better indicator of the impact on surgery on postoperative period of this patients and factors that influence it should be well known. KEY WORDS: Surveillance, Colon cancer, 1-year mortality.