Surveillance of patients at high risk for colorectal cancer

Annual Blood Tests Are an Acceptable form of Surveillance to Supplement Colonoscopies for Colorectal Cancer

BACKGROUND

Individuals at increased risk of colorectal cancer (CRC) are recommended surveillance colonoscopies as a preventative measure, but timely provision of colonoscopies remains a significant hurdle. Biomarker testing has emerged as a potential strategy to mitigate excessive colonoscopy use by prioritizing procedures for those most at risk of CRC. However, the acceptability of supplementing surveillance colonoscopies with regular blood tests is unknown.

AIM

To evaluate patient acceptance of a hypothetical surveillance protocol providing annual blood tests between 5-yearly colonoscopies.

METHODS

Eight hundred individuals enrolled in an Australian surveillance colonoscopy program were invited to complete a survey on surveillance preferences. Ordinal logistic regression analysis was performed to assess the influence of sociodemographic, clinical, and psychological variables on participants' comfort with the surveillance protocol.

RESULTS

A total of 409 (51%) individuals participated, with 346 (51% male, mean age 63 years) providing complete outcome data. Most participants (n = 250/346, 72%) reported being comfortable with the surveillance protocol. Significantly higher levels of comfort were reported by individuals with greater confidence in their ability to undergo blood testing (OR 1.26, 95% CI 1.08-1.47, p = 0.003) and those having less frequent surveillance colonoscopies (OR 1.26, 95% CI 1.01-1.58, p = 0.043). Significant associations were not observed between other variables and comfort with the surveillance protocol (p > 0.05).

CONCLUSIONS

Annual blood testing between surveillance colonoscopies was highly accepted by individuals at increased risk of CRC. Offering new blood-based modalities to specific subpopulations, particularly individuals who are more comfortable with blood testing, or those having less frequent surveillance colonoscopies, could enhance overall acceptance.

Guidelines for the management of neuroendocrine tumours by the Brazilian gastrointestinal tumour group

Neuroendocrine tumours are a heterogeneous group of diseases with a significant variety of diagnostic tests and treatment modalities. Guidelines were developed by North American and European groups to recommend their best management. However, local particularities and relativisms found worldwide led us to create Brazilian guidelines. Our consensus considered the best feasible strategies in an environment involving more limited resources. We believe that our recommendations may be extended to other countries with similar economic standards.

Exome sequencing in one family with gastric- and rectal cancer

Background

Heritable factors are well known to increase the risk of cancer in families. Known susceptibility genes account for a small proportion of all colorectal cancer cases. The aim of this study was to identify the genetic background in a family suggested to segregate a dominant cancer syndrome with a high risk of rectal- and gastric cancer. We performed whole exome sequencing in three family members, 2 with rectal cancer and 1 with gastric cancer and followed it up in additional family members, other patients and controls.

Results

We identified 12 novel non-synonymous single nucleotide variants, which were shared among 5 affected members of this family. The mutations were found in 12 different genes; DZIP1L, PCOLCE2, IGSF10, SUCNR1, OR13C8, EPB41L4B, SEC16A, NOTCH1, TAS2R7, SF3A1, GAL3ST1, and TRIOBP. None of the mutations was suggested as a high penetrant mutation. It was not possible to completely rule out any of the mutations as contributing to disease, although seven were more unlikely than the others. Neither did we rule out the effect of all thousands of intronic, intergenic and synonymous variants shared between the three persons used for exome sequencing.

Conclusions

We propose this family, suggested to segregate dominant disease, could be an example of complex inheritance.

Article Commentary: Surgical Prophylaxis for Inheritable Malignant Diseases: Colorectal and Gastric Cancer

Despite advances in modern medicine, cancer remains all too common and deadly. At its core, cancer is a disease of our DNA. As such, many cancers are passed from parents to children, making cancer one of the most commonly inherited diseases. Presently, we have no meaningful methods of “preventing” the malignant transformation that occurs as a result of an inherited gene, but investigators have identified several genetic mutations and subsequently developed risk-reduction strategies that sometimes involve surgery.

Reducing the incidence and mortality of colon cancer: mass screening and colonoscopic polypectomy

Most colon cancers arise from conventional adenomatous polyps (conventional adenoma-to-carcinoma sequence), while some colon cancers appear to arise from the recently recognized serrated adenomatous polyp (serrated adenoma-to-carcinoma theory). Because conventional adenomas and serrated adenomas are usually asymptomatic, mass screening of asymptomatic patients has become the cornerstone for detecting and eliminating these precursor lesions to reduce the risk of colon cancer. Colonoscopy has become the primary screening test because of its high sensitivity and specificity, and the ability to perform polypectomy. Other screening tests include guaiac tests or fecal immunochemical tests (FIT) for fecal occult blood, and flexible sigmoidoscopy. A minimal colonoscopic withdrawal time of 6 minutes is important to maximize polyp detection at colonoscopy. Chromoendoscopy is an experimental technique used to highlight abnormal colonic areas to identify neoplastic tissue and to potentially determine the histology of colonic polyps at colonoscopy based on superficial pit anatomy.

Colorectal cancer screening and surveillance

Screening and surveillance substantially reduce both the incidence and mortality of colorectal cancer. Screening of normal-risk individuals may be accomplished by several methods, including fecal occult blood testing, fiberoptic sigmoidoscopy, double contrast barium enema, and colonoscopy. New technologies for screening are being developed, such as fecal immunochemical testing for blood,fecal DNA testing, and virtual colonoscopy. Patients at increased risk for colorectal cancer, such as those with a positive family history, previous adenomatous polyps or cancer, and inflammatory bowel disease, should be offered more intensive evaluation and surveillance.