Biomedical subjects

Andrea E de Jong

Publications and source records attributed to Andrea E de Jong.

5 recordsLinked to original sources

PubMed2006

Decrease in mortality in Lynch syndrome families because of surveillance.

BACKGROUND & AIMS: Lynch syndrome family members have a high risk of developing colorectal (CRC), endometrial (EC), and other cancers. A large-scale surveillance program was introduced in The Netherlands in the late 1980s. The aims of the study were to evaluate the effectiveness of this program by assessing mortality because of CRC and EC before and after 1990 and to compare mortality because of all cancers (except CRC/EC) with mortality in the general population. METHODS: Family members with at least 50% probability of being a carrier were selected for the study. The standardized mortality ratio (SMR) because of cancer and the absolute excess risk of death (AER) were calculated. RESULTS: In the total cohort (N = 2788), 445 subjects had died because of cancer. The 3 most frequent causes of cancer-related deaths were CRC (50.3%), EC (6.7%), and brain tumors (6.7%). A significant decrease (70%) in SMR for CRC over time was observed (P < .001); the SMR for EC showed no decreasing trend over time. A significantly increased SMR was found for cancer of the small bowel (SMR = 18.3), brain (SMR = 9.1), kidney/ureter (SMR = 5.9), ovarium (SMR = 2.3), pancreas (SMR = 2.2), and stomach (SMR = 2.1). The AER was significantly increased for brain tumors only. CONCLUSIONS: Since the introduction of surveillance, the mortality because of CRC has decreased. Except for brain tumors, we did not find a significantly increased AER for tumors other than CRC/EC.

Adult↗

PubMed2006

Prospective results of surveillance colonoscopy in dominant familial colorectal cancer with and without Lynch syndrome.

BACKGROUND & AIMS: Lynch syndrome is an autosomal dominant predisposition to colorectal cancer caused by mutations in DNA mismatch repair genes; colorectal cancer risk is high. Few studies have addressed colorectal cancer risk in individuals from dominant families without mismatch repair deficiency. We sought to establish whether these individuals are also at increased risk by examining the incidence of advanced neoplasia during surveillance. METHODS: In this prospective cohort study, BAT26 testing of tumors was carried out at 2 tertiary centers on 125 individuals from 97 families (with a dominant colorectal cancer history) to classify families as Lynch syndrome (microsatellite unstable) or non-Lynch syndrome (microsatellite stable). Colonoscopy results in 288 at-risk family members were compared. RESULTS: Twenty-nine families were classified as Lynch syndrome and 68 as non-Lynch syndrome. Seven hundred seventy-six colonoscopies were undertaken. High-risk adenomas occurred in 7 of 91 (7.7%) Lynch syndrome individuals and 15 of 197 (7.6%) non-Lynch syndrome individuals, adjusted relative risk 1.15 (95% CI: 0.6-2.3). Cancer was observed only in Lynch syndrome individuals (4/91; 4.4%), Fisher exact test, P = .010. Multiple adenomas were only seen in non-Lynch syndrome individuals (13/197; 6.6%), Fisher exact text, P = .06. CONCLUSIONS: Individuals with an autosomal dominant family history of colorectal cancer with and without evidence of Lynch syndrome are at equal risk of high-risk adenomas during surveillance, but colorectal cancer was only seen in Lynch syndrome. Therefore non-Lynch syndrome individuals do require colonoscopic surveillance, but the interval could be lengthened because risk of (interval) cancer is low. Lynch syndrome individuals require short surveillance intervals as is the recommended practice.

Age Distribution↗

PubMed2005

Prevalence of adenomas among young individuals at average risk for colorectal cancer.

OBJECTIVES: We evaluated the prevalence and characteristics of adenomas in a young population not genetically predisposed for the development of colorectal cancer (CRC). METHODS: The databases of the Dutch Hereditary Colorectal Cancer Registry were used. The study population included patients (n = 444) who had regular endoscopy until mutation analysis revealed they did not carry the (Adenomatous Polyposis Coli (APC)/Mismatch Repair) gene defect identified in their family. RESULTS: At first colonoscopy (n = 342; 50% males, mean age 37 yr) a total of 19 adenomas (10 males, mean age 50 yr, range 24-91 yr) and two CRCs (2 males, age 49 and 72 yr) were identified, and at first sigmoidoscopy (n = 102; 53% males, mean age 29 yr) three adenomas (2 males, age 8, 40, and 41 yr) were found. A second colonoscopy was performed in 14 patients with, and in 162 patients without an adenoma. Three of 14 patients (21%) developed a new adenoma (all >50 yr) and 8 of 162 (5%) patients developed their first adenoma during follow-up. In the colonoscopy group, the cumulative proportion of patients free of adenomas at age 50 yr was 86%. Of all adenomas diagnosed during colonoscopy (n = 49), 65% were located distal from the flexura lienalis. Of the adenomas detected during all endoscopies (n = 53), 9.8% were > or =7 mm, 7.5% showed high-grade dysplasia, and 7.5% showed tubulovillous features. CONCLUSIONS: On the basis of our findings during colonoscopy we conclude that the risk of developing adenomas/CRC in young individuals without genetic risk factors is low. Adenoma surveillance programs should focus on young individuals with a positive family (or personal) history for adenomas/CRC, or on individuals >50 yr.

Adenoma↗

PubMed2004

Microsatellite instability, immunohistochemistry, and additional PMS2 staining in suspected hereditary nonpolyposis colorectal cancer.

PURPOSE: Immunohistochemistry (IHC) and microsatellite instability (MSI) analysis can be used to identify patients with a possible DNA mismatch repair defect [hereditary nonpolyposis colorectal carcinoma (HNPCC)]. The Bethesda criteria have been proposed to select families for determination of MSI. The aims of this study were to assess the yield of MSI analysis in families suspected for HNPCC, to compare the results of immunohistochemical staining and MSI analysis, and to assess the additional value of PMS2 staining. EXPERIMENTAL DESIGN: Clinical data and tumors were collected from 725 individuals from 631 families with suspected HNPCC. MSI analysis was performed using eight markers including the 5 National Cancer Institute markers. Four immunohistochemical staining antibodies were used (MLH1, MSH2, MSH6 and PMS2). RESULTS: A MSI-H (tumors with instability for >30% of the markers) phenotype in colorectal cancers (CRCs) was observed in 21-49% of families that met the various Bethesda criteria. In families with three cases of CRC diagnosed at age > 50 years, families with a solitary case of CRC diagnosed between ages 45 and 50 years, and families with one CRC case and a first-degree relative with a HNPCC-related cancer, one diagnosed between ages 45 and 50 years (all Bethesda-negative families), the yield of MSI-H was 10-26%. Immunohistochemical staining confirmed the MSI results in 93% of the cases. With IHC, adding PMS2 staining led to the identification of an additional 23% of subjects with an hMLH1 germ-line mutation (35 carriers were tested). CONCLUSIONS: The Bethesda guidelines for MSI analysis should include families with three or more cases of CRC diagnosed at age > 50 years. The age at diagnosis of CRC in the original guidelines should be raised to 50 years. Routine IHC diagnostics for HNPCC should include PMS2 staining.

Adenosine Triphosphatases↗

PubMedDate not supplied

Diagnostic approach and management of Lynch syndrome (hereditary nonpolyposis colorectal carcinoma): a guide for clinicians.

ABSTRACT diagnostic workup of familial colorectal cancer is an elaborate and time consuming process in which the family and several medical specialists closely collaborate. However, establishing a diagnosis can be very rewarding. If a mutation is detected in the family, a satisfactory explanation can be provided for an accumulation of tumors at young age, and often of untimely death. Appropriate presymptomatic testing can be offered to reduce mortality among at-risk family members, and relatives not at risk can avoid uncertainty and needlessly intensive surveillance. We show the differential diagnostic considerations when an individual with a family history of colorectal carcinoma is encountered, with emphasis on Lynch syndrome (Hereditary Nonpolyposis Colorectal Carcinoma [HNPCC]). Practical recommendations for laboratory workup of suspected Lynch syndrome, including analysis of tumor tissue by microsatellite instability analysis and immunohistochemistry, and germline DNA analysis are given. Furthermore, the clinical management after a molecular diagnosis has been made is described. The diagnostic scheme presented here allows efficient and effective analysis of colorectal carcinoma cases with (suspected) Lynch syndrome, making optimal use of currently available technology.

Colorectal Neoplasms, Hereditary Nonpolyposis↗