Clinicopathological differences and correlations between right and left colon cancer

BACKGROUND The differences in histopathology and molecular biology between right colon cancer(RCC)and left colon cancer(LCC)were first reported in the literature by Bufill in 1990.Since then,a large number of studies have confirmed their differences in epidemiology,clinical presentation,comorbidities and biological behaviours,which may be related to the difference in prognosis and overall survival(OS)between the two groups.AIM To investigate statistically significant differences between Greek patients with LCC and RCC.METHODS The present observational study included 144 patients diagnosed with colon cancer of any stage who received chemotherapy in a Greek tertiary oncology hospital during a 2.5-year period.Clinical information,comorbidities,histopathologic characteristics and molecular biomarkers were collected from the patients’medical records retrospectively,while administered chemotherapy regimens,targeted agents,progression-free survival(PFS)periods with first-and second-line chemotherapy and OS were recorded retroactively and prospectively.Data analysis was performed with the SPSS statistical package.RESULTS Eighty-six males and 58 females participated in the study.One hundred(69.4%)patients had a primary lesion in the left colon,and 44(30.6%)patients had a primary lesion in the right colon.Patients with RCC were more likely to display anaemia than patients with LCC[odds ratio(OR)=3.09],while LCC patients were more likely to develop rectal bleeding(OR=3.37)and a feeling of incomplete evacuation(OR=2.78)than RCC patients.Considering comorbidities,RCC patients were more likely to suffer from diabetes(OR=3.31)and coronary artery disease(P=0.056)than LCC patients.The mucinous differentiation rate was higher in the right-sided group than in the left-sided group(OR=4.49),as was the number of infiltrated lymph nodes(P=0.039),while the percentage of high-grade differentiation was higher in the group of patients with left-sided colon cancer than in RCC patients(OR=2.78).RAS wild-type patients who received anti-epidermal growth factor receptor(EGFR):Treatment experienced greater benefit(PFS:16.5 mo)than those who received anti-vascular endothelial growth factor treatment(PFS:13.7 mo)(P=0.05),while among RAS wild-type patients who received anti-EGFR treatment,LCC patients experienced greater benefit(PFS:15.8 mo)than the RCC subgroup(PFS:5.5 mo)in the first-line chemotherapy setting(P=0.034).BRAF-mutant patients had shorter PFS(9.3 mo)than BRAF wild-type patients(14.5 mo)(P=0.033).RCC patients showed a shorter tumour recurrence period(7.7 mo)than those with LCC(14.5 mo)(P<0.001),as well as shorter(OS)(58.4 mo for RCC patients;82.4 mo for LCC patients)(P=0.018).CONCLUSION RCC patients present more comorbidities,worse histological and molecular characteristics and a consequently higher probability of tumour recurrence,poor response to targeted therapy and shorter OS than LCC patients.

COVID-19 in the endoscopy unit:How likely is transmission of infection?Results from an international,multicenter study

BACKGROUND Coronavirus disease 2019(COVID-19)significantly affected endoscopy practice,as gastrointestinal endoscopy is considered a risky procedure for transmission of infection to patients and personnel of endoscopy units(PEU).AIM To assess the impact of COVID-19 on endoscopy during the first European lockdown(March-May 2020).METHODS Patients undergoing endoscopy in nine endoscopy units across six European countries during the period of the first European lockdown for COVID-19(March-May 2020)were included.Prior to the endoscopy procedure,participants were stratified as low-or high-risk for potential COVID-19 infection according to the European Society of Gastrointestinal Endoscopy(ESGE)and the European Society of Gastroenterology and Endoscopy Nurses and Associates(ESGENA)joint statement,and contacted 7-14 d later to assess COVID-19 infection status.PEU were questioned regarding COVID-19 symptoms and/or infection via questionnaire,while information regarding hospitalizations,intensive care unitadmissions and COVID-19-related deaths were collected.The number of weekly endoscopies at each center during the lockdown period was also recorded.RESULTS A total of 1267 endoscopies were performed in 1222 individuals across nine European endoscopy departments in six countries.Eighty-seven(7%)were excluded because of initial positive testing.Of the 1135 pre-endoscopy low risk or polymerase chain reaction negative for COVID-19,254(22.4%)were tested post endoscopy and 8 were eventually found positive,resulting in an infection rate of 0.7%[95%CI:0.2-0.12].The majority(6 of the 8 patients,75%)had undergone esophagogastroduodenoscopy.Of the 163 PEU,5[3%;(95%CI:0.4-5.7)]tested positive during the study period.A decrease of 68.7%(95%CI:64.8-72.7)in the number of weekly endoscopies was recorded in all centers after March 2020.All centers implemented appropriate personal protective measures(PPM)from the initial phases of the lockdown.CONCLUSION COVID-19 transmission in endoscopy units is highly unlikely in a lockdown setting,provided endoscopies are restricted to emergency cases and PPM are implemented.