The revised Bethesda guidelines: extent of utilization in a university hospital medical center with a cancer genetics program

[French ccAFU guidelines - update 2020-2022: upper urinary tract urothelial carcinoma]

INTRODUCTION

-The purpose was to propose an update of the French guidelines from the national committee ccAFU on upper tract urothelial carcinomas (UTUC).

METHODS

- A systematic Medline search was performed between 2018 and 2020, as regards diagnosis, options of treatment and follow-up of UTUC, to evaluate different references with levels of evidence.

RESULTS

- The diagnosis of this rare pathology is based on CT-scan acquisition during excretion and ureteroscopy with histological biopsies. Radical nephroureterectomy (RNU) remains the gold standard for surgical treatment, nevertheless a conservative endoscopic approach can be proposed for low risk lesion: unifocal tumor, possible complete resection and low grade and absence of invasion on CT-scan. Close monitoring with endoscopic follow-up (flexible ureteroscopy) in compliant patients is therefore necessary. After RNU, bladder instillation of chemotherapy is recommended to reduce risk of bladder recurrence. A systemic chemotherapy is recommended after RNU in pT2-T4 N0-3 M0 disease.

CONCLUSION

- These updated guidelines will contribute to increase the level of urological care for diagnosis and treatment for UTUC.

Correlation of immunohistochemical mismatch repair protein status between colorectal carcinoma endoscopic biopsy and resection specimens

Background

Microsatellite instability is reflective of a deficient mismatch repair system (dMMR), which may be due to either sporadic or germline mutations in the relevant mismatch repair (MMR) gene. MMR status is frequently determined by immunohistochemistry (IHC) for mismatch repair proteins (MMRPs) on colorectal cancer (CRC) resection specimens. However, IHC testing performed on endoscopic biopsy may be as reliable as that performed on surgical resections.

Aim

We aimed to evaluate the reliability of MMR IHC staining on preoperative CRC endoscopic biopsies compared with matched-surgical resection specimens.

Methods

A retrospective search of our institution’s histopathology electronic database was performed. Patients with CRC who had MMR IHC performed on both their preoperative endoscopic biopsy and subsequent resection from January 2010 to January 2016 were included. Concordance of MMR staining between biopsy and resection specimens was assessed.

Results

From 2000 to 2016, 53 patients had MMR IHC performed on both their preoperative colorectal endoscopic biopsy and resection specimens; 10 patients (18.87%) demonstrated loss of ≥1 MMRP on their initial endoscopic tumour biopsy. The remainder (81.13%) showed preservation of staining for all MMRPs. There was complete agreement in MMR IHC status between the preoperative endoscopic biopsies and corresponding resection specimens in all cases (κ=1.000, P<0.000) with a sensitivity of 100% (95% CI 69.15 to 100) and specificity of 100% (95% CI 91.78 to 100) for detection of dMMR.

Conclusion

Endoscopic biopsies are a suitable source of tissue for MMR IHC analysis. This may provide a number of advantages to both patients and clinicians in the management of CRC.

Underutilization of Lynch syndrome screening in a multisite study of patients with colorectal cancer

PURPOSE

The aim of this study was to examine Lynch syndrome screening of patients with metastatic colorectal cancer in integrated health-care-delivery organizations.

METHODS

We determined the availability of Lynch syndrome screening criteria and actual Lynch syndrome screening in the medical records of 1,188 patients diagnosed with metastatic colorectal cancer between 2004 and 2009 at seven institutions in the Cancer Research Network.

RESULTS

We found infrequent use of Lynch syndrome screening (41/1,188). Family history was available for 937 of the 1,188 patients (79%). There was sufficient information to assess Lynch syndrome risk using family history-based criteria in 719 of the 937 patients (77%) with family history documentation. In 391 individuals with a family history of a Lynch syndrome-associated cancer, 107 (27%) could not be evaluated due to missing information such as age of cancer onset. Eleven percent of patients who met the Bethesda criteria and 25% of individuals who met the Amsterdam II criteria were screened for Lynch syndrome. Recommended guidelines were adhered to during screening, but no testing method was preferred.

CONCLUSION

The information required for Lynch syndrome screening decisions is routinely collected but seldom used. There is a critical gap between collection of family history and its use to guide Lynch syndrome screening, which may support a case for implementation of universal screening guidelines.

Lynch or not Lynch? Is that always a question?

The familial cancer syndrome referred to as Lynch I and II was renamed hereditary nonpolyposis colorectal cancer (HNPCC) only to revert later to Lynch syndrome (LS). LS is the most frequent human predisposition for the development of colorectal cancer (CRC), and probably also for endometrial and gastric cancers, although it has yet to acquire a consensus name. Its estimated prevalence ranges widely from 2% to 7% of all CRCs due to the fact that tumors from patients with LS are difficult to recognize at both the clinical and molecular level. This review is based on two assumptions. First, all LS patients inherit a predisposition to develop CRC (without polyposis) and/or other tumors from the Lynch spectrum. Second, all LS patients have a germline defect in one of the DNA mismatch repair (MMR) genes. When a somatic second hit inactivates the relevant MMR gene, the consequence is instability of DNA repeat sequences such as microsatellites and the tumors are referred to as having the microsatellite instability (MSI) phenotype. However, some of the inherited predisposition to develop CRC without concurrent polyposis, termed HNPCC, is found in non-LS patients, while not all MSI tumors are from LS cases. LS tumors are therefore at the junction of inherited and MSI cases. We describe here the defining characteristics of LS tumors that differentiate them from inherited non-MSI tumors and from non-inherited MSI tumors.

Simplified identification of Lynch syndrome: a prospective, multicenter study

BACKGROUND

Recommended strategies to screen for Lynch syndrome in colorectal cancer are not applied in daily practice and most of Lynch cases remain undiagnosed.

AIMS

We investigated in routine conditions a strategy that uses simplified clinical criteria plus detection of MisMatch Repair deficiency in tumours to identify Lynch carriers.

METHODS

Colorectal cancer patients that met at least one of three clinical criteria were included: (1) colorectal cancer before 50 years, (2) personal history of colorectal or endometrial cancer, (3) first-degree relative history of colorectal or endometrial cancer. All tumours underwent an MisMatch Repair test combining microsatellite instability analysis and MisMatch Repair immunohistochemistry. Patients with an MisMatch Repair-deficient tumour were offered germline testing.

RESULTS

Of the 307 patients fulfilling the clinical criteria, 46 (15%) had a MisMatch Repair-deficient tumour. Amongst them 27 were identified as Lynch carriers (20 with germline mutation: 12 MLH1, 7 MSH2, 1 MSH6; 7 highly suspected cases despite failure of genetic testing). The simplified clinical criteria selected a population whose MisMatch Repair-deficient status was highly predictive (59%) of Lynch syndrome.

CONCLUSION

This bio-clinical strategy based on simplified clinical criteria combined with an MisMatch Repair test efficiently detected LS cases and is easy to use in clinical practice, outside expert centres.

Screening for Familial Colorectal Cancer Risk amongst Colonoscopy Patients New to an Open-Access Endoscopy Center

Purpose. We evaluated a questionnaire to aid in the recognition of CRC risk, as well as patient interest in their risk status within an open-access endoscopy center. Methods. A questionnaire was administered to new patients presenting for colonoscopy from May 2007 to February 2008. 287 patients were enrolled. Family history was evaluated using Amsterdam 1, II, and Revised Bethesda criteria. Recognition of risk and referral for counseling was assessed. Patients' interest to be contacted by a genetic counselor was also assessed. Results. 13.2 % (38/287) of patients met Revised Bethesda criteria. Of these, 18 (47.4 %) were previously told about their increased risk for CRC. Only 1 patient who met Revised Bethesda criteria (2.6 %) was previously referred for genetics, whereas none of the 3 patients who met Amsterdam I or II criteria were referred. 23.7 % of high-risk patients did not want to be contacted if found to be at increased risk for cancer. Conclusion. In our open-access endoscopy system, a significant number of high-risk patients remain unidentified and underreferred for genetic counseling due to numerous barriers. Our findings lend support to taking a public health approach to identifying those at risk for Lynch syndrome by implementing universal screening of all CRC specimens.

Barriers to and motivations for physician referral of patients to cancer genetics clinics

Although it is well known that under-referral of colon cancer patients to cancer genetics clinics is a chronic problem, no study has yet examined why physicians may be ordering testing independently rather than referring patients to cancer genetics clinics. The current study explored variables which may impact a physician's preference for ordering testing independently or referring patients to outside cancer genetics experts. An online questionnaire, distributed to the membership of the American College of Gastroenterology and the American Society of Colorectal Surgeons, yielded responses from 298 physicians. Motivations to refer to cancer genetics clinics rather than order testing independently included fear of genetic discrimination and a belief that patients benefit from genetic counseling about the risks, benefits and consequences of testing. These results suggest that in order to increase referrals, genetic counselors must educate physicians about the unique benefits patients receive from participating in genetic counseling.