Evidence based medicine and surgical approaches for colon cancer: Evidences, benefits and limitations of the laparoscopic vs open resection

AIM:To report a meta-analysis of the studies that compared the laparoscopic with the open approach for colon cancer resection.METHODS:Forty-seven manuscripts were reviewed,33 of which employed for meta-analysis according to the PRISMA guidelines.The results were differentiated according to the study design(prospective randomized trials vs case-control series)and according to the tu-mor’s location.Outcome measures included:(1)shortterm results(operating times,blood losses,bowel function recovery,post-operative pain,return to the oral intake,complications and hospital stay);(2)oncological adequateness(number of nodes harvested in the surgical specimens);and(3)long-term results(including the survivals’rates and incidence of incisional hernias)and(4)costs.RESULTS:Meta-analysis of trials provided evidences in support of the laparoscopic procedures for a several short-term outcomes including:a lower blood loss,an earlier recovery of the bowel function,an earlier return to the oral intake,a shorter hospital stay and a lower morbidity rate.Opposite the operating time has been confirmed shorter in open surgery.The same trend has been reported investigating case-control series and cancer by sites,even though there are some concerns regarding the power of the studies in this latter field due to the small number of trials and the small sample of patients enrolled.The two approaches were comparable regarding the mean number of nodes harvested and long-term results,even though these variables were documented reviewing the literature but were not computable for meta-analysis.The analysis of the costs documented lower costs for the open surgery,however just few studies investigated the incidence of postoperative hernias.CONCLUSION:Laparoscopy is superior for the majority of short-term results.Future studies should better differentiate these approaches on the basis of tumors’location and the post-operative hernias.

Human papillomavirus does not have a causal role in colorectal carcinogenesis

AIM: To investigate the presence of human papillomavirus(HPV) DNA along with the integration,the quantification and the expression of the HPV16 in colorectal cancers.METHODS: A prospective series of colorectal tumors were genotyped for HPV DNA.The clinical and pathological variables of the HPV-positive tumors were compared to those of HPV-negative samples.The integration status of HPV16 was evaluated by calculating E2/E6 ng ratios.HPV16-positive tumors were also evaluated for(1) E2,E4,E5,E6 and E7 viral gene ng quantification;(2) relative quantification compared to W12 cells; and(3) viral E2,E4,E5,E6 and E7 mR NA transcripts by real-time polymerase chain reaction.RESULTS: HPV infection was detected in 16.9% of all tumors examined,and HPV16 was the most frequent type detected(63.6% of positive tissues).Notably,the clinical and pathological features of HPV-positive colorectal cancers were not significantly different than those of HPV-negative cancers(χ2 and t-test for all clinical and pathological features of HPV-positive vs HPV-negative colorectal cancers: p ns).HPV16 DNA was present exclusively in episomal form,and the HPV16 E2,E4,E5,E6 and E7 genes were detected in tracenanogram quantities.Furthermore,the HPV16 genes ranged from 10-3 to 10-9 compared to W12 cells at an episomal stage.Although the extractions were validated by housekeeping gene expression,all the HPV16 positive tissues were transcriptionally inactive for the E2,E4,E5,E6 and E7 mR NAs.CONCLUSION: Based on our results,HPV is unlikely involved in colorectal carcinogenesis.

Is proliferative colonic disease presentation changing?

AIM:To compare the site,age and gender of cases of colorectal cancer(CRC) and polyps in a single referral center in Rome,Italy,during two periods.METHODS:CRC data were collected from surgery/pathology registers,and polyp data from colonoscopy reports.Patients who met the criteria for familial adenomatous polyposis,hereditary non-polyposis colorectal cancer syndrome or inflammatory bowel disease were excluded from the study.Overlap of patients between the two groups(cancers and polyps) was carefully avoided.Theχ 2 statistical test and a regression analysis were performed.RESULTS:Data from a total of 768 patients(352 and 416 patients,respectively,in periods A and B) who underwent surgery for cancer were collected.During the same time periods,a total of 1693 polyps were analyzed from 978 patients with complete colonoscopies(428 polyps from 273 patients during period A and 1265 polyps from 705 patients during period B).A proximal shift in cancer occurred during the latter years for both sexes,but particularly in males.Proximal cancer increased > 3-fold in period B compared to period A in males [odds ratio(OR) 3.31,95%CI:2.00-5.47;P < 0.0001).A similar proximal shift was observed for polyps,particularly in males(OR 1.87,95%CI:1.23-2.87;P < 0.0038),but also in females(OR 1.62,95%CI:0.96-2.73;P < 0.07).CONCLUSION:The prevalence of proximal proliferative colonic lesions seems to have increased over the last decade,particularly in males.