Surgical Implications of Colorectal Cancer Genetics

Efficacy, functional outcome and post-operative complications of total abdominal colectomy with ileorectal anastomosis vs. segmental colectomy in hereditary non-polyposis colorectal cancer

The primary objective of the present study was to compare the choice of colectomy, i.e. total vs. segmental colectomy, in cases of hereditary non-polyposis colorectal cancer (HNPCC/lynch syndrome), and to assess the efficacy, oncological safety, functional outcome and post-operative complications of total abdominal colectomy with ileorectal anastomosis vs. segmental colectomy in HNPCC. A total of 289 patients who fulfilled the Amsterdam I and II criteria for HNPCC were included in the present study. The criteria for confirmation of the diagnosis were five micro-satellite markers, namely BAT25, BAT26, D2s123, d5S346 and D17S250. Group 1 included those patients who received their diagnosis in the years 2011–2013 and those in group 2 had been diagnosed in the years 2014–2016. The cohort had been subjected to two different types of surgery: i) Standard and extended surgery including total colectomy with ileal pouch anal anastomosis and subtotal colectomy and ii) segmental resection of the colon. Analysis of patient data indicated that in group 1, the extended resection was performed more frequently than in group 2 (68 vs. 34% of cases) and accordingly, segmental resection was less frequent (32 vs. 66%; P<0.001). In conclusion, the extensive rather than the segmental resection has been commonly performed several years ago, but at present, the surgical method of choice in cases of lynch syndrome is segmental resection. Trial registry no. QU/MR2011/CRC5, dated 21 March 2011.

Extracolonic manifestations of hereditary colorectal cancer syndromes

Familial colorectal adenocarcinoma (CRC) accounts for approximately 15 to 20% of CRC. Of these, hereditary nonpolyposis colorectal cancer (HNPCC) and familial adenomatous polyposis (FAP) represent the most common hereditary syndromes associated with CRC, followed by other less common diseases including juvenile polyposis (JP) and Peutz-Jeghers syndrome (PJS). Extracolonic manifestations are common in each of these syndromes having significant implications for surveillance and management in at-risk individuals. The authors review the most common and clinically relevant extracolonic manifestations for each of these syndromes focusing on incidence, presentation, genotype/phenotype correlations, and management (including surveillance) strategies.

Stage migration in colorectal cancer related to improved lymph node assessment

AIM

The aim of the study was to evaluate the clinical impact of improved cooperation between the treating surgeons and pathologists in a high volume surgical unit. As a measure we used the staging process with special focus on lymph node assessment.

FINDINGS

Comparing two periods 5 years apart, we found a significant increase in the number of nodes examined and also an increase in the number of metastasis-positive nodes. Concurrently, we observed a trend in stage migration from stage I/II towards stage III, whilst stage IV remained unchanged. This was one factor that contributed to an increase in the number of patients treated with adjuvant chemotherapy. We also found that the number of assessed nodes had an impact on survival in stage II. The major change in practise was the implementation of a multidisciplinary team conference and the associated possibility of reciprocal feedback.

CONCLUSION

Lymph node status has a key role in cancer staging and in the selection of further therapy. The quality and the standard of the assessment can be improved through multidisciplinary cooperation and it has an impact on the clinical decisions and can affect long-term survival. A correct node status should be mandatory in the evaluation of prognostic factors.

Who should be sent for genetic testing in hereditary colorectal cancer syndromes?

Genetic testing is being adopted increasingly to identify individuals with germline mutations that predispose to hereditary colorectal cancer syndromes. Deciding who to test and for which syndrome is of concern to members of the GI oncology community, molecular geneticists, and genetic counselors. The purpose of this review is to help provide guidelines for testing, given that the results influence syndrome diagnosis and clinical management. Although family history may determine whether testing is appropriate and may direct testing to the most informative family member, evolving clinicopathologic features can identify individual patients who warrant testing. Thus, although the usual absence of clinical premonitory signs in hereditary nonpolyposis colorectal cancer (or Lynch syndrome) adds difficulty to its diagnosis, use of the Amsterdam Criteria and Bethesda Guidelines can prove helpful. In contrast, premonitory stigmata such as pigmentations in Peutz-Jeghers syndrome and the phenotypic features of familial adenomatous polyposis aid significantly in syndrome diagnosis. We conclude that the physician's role in advising DNA testing is no small matter, given that a hereditary cancer syndrome's sequelae may be far reaching. Genetic counselors may be extremely helpful to the practicing gastroenterologist, oncologist, or surgeon; when more specialized knowledge is called for, referral can be made to a medical geneticist and/or a medical genetics clinic.