Who Should Be Sent for Genetic Testing in Hereditary Colorectal Cancer Syndromes?

Baylor University, Waco, Texas, United States
Journal of Clinical Oncology (Impact Factor: 18.43). 09/2007; 25(23):3534-42. DOI: 10.1200/JCO.2006.10.3119
Source: PubMed


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.

Full-text preview

Available from:
  • Source
    • "While identifying genetic susceptibility to cancer provides an opportunity for preventive behavior, including improvement in diet, exercise, and screening practices, negative consequences are also possible. For example, a recent paper by Lynch et al. (2007) noted the potential emotional distress that may occur following identification of a genetic susceptibility to cancer, as well as the distress that those who have negative or ambiguous results can experience. These findings highlight the importance of evaluating participant willingness a priori to receive such information and discussing implications of results. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Recent developments in genetic testing allow us to detect individuals with inherited susceptibility to some cancers. Genetic testing to identify carriers of cancer-related mutations may help lower risk by encouraging preventive behaviors and surveillance. This study assessed willingness of colon cancer cases and relatives to receive genetic information that may indicate an increased risk for cancer, to whom they would disclose genetic information, and whether receiving genetic test results may influence future prevention behaviors among individuals enrolled in the Seattle Colorectal Cancer Family Registry. Incident invasive colorectal cancer cases were identified from the Puget Sound Surveillance Epidemiology and End Results (SEER) registry. In 2007, a sequential sample of cases and relatives (n = 147) were asked to respond to a questionnaire addressing study aims. The questionnaire was administered during a baseline or 5-year follow-up interview. Patterns of response to each statement were similar between colorectal cancer cases and relatives. Both colorectal cases (95%) and relatives (95%) reported willingness to receive genetic information. Nearly all participants would tell their doctor the results of a genetic test (99% of cases; 98% of relatives), and all married participants would tell their spouses. Cases (96%) anticipated being slightly more likely than relatives (90%) to change their cancer screening behavior, but this difference was not statistically significant (p = 0.33). A high percentage of both colorectal cancer cases and relatives sampled from the Seattle Colorectal Cancer Family Registry are interested in identifying their genetic status, discussing their genetic status with their family and doctor, and adopting behavioral changes that may reduce cancer risk.
    Full-text · Article · Oct 2008 · Genetic Testing
  • [Show abstract] [Hide abstract]
    ABSTRACT: Apoptosis and autophagic cell deaths are programmed cell deaths and they play essential roles in cell survival, growth and development and tumorigenesis. The huge increase of publications in both apoptosis and autophagic signaling pathways has contributed to the wealth of knowledge in facilitating the understanding of cancer pathogenesis. Deciphering the molecular pathways and molecules involved in these pathways has helped scientists devise and develop targeted strategies against cancer. Various drugs targeting the apoptotic TRAIL, Bcl-2 and proteasome pathways are already in Phase II/III clinical trials. The first mTOR inhibitor, temsirolimus has already been approved by the FDA, USA for the treatment of advanced renal cell carcinoma and more mTOR inhibitors are expected to be in the market in a few years time. Strategizing against aberrant autophagy activities in various cancers by using either pro-autophagics or autophagy inhibitors are currently been investigated. This review aims to discuss the most recent antitumor strategies targeting the apoptosis and autophagy signaling pathways and the latest outcome of clinical trials of the above drugs.
    No preview · Article · Jul 2009 · Pharmaceutical Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Hereditary breast cancer (HBC) accounts for as much as 10% of the total BC burden. Most of these cases will be found to be due to a BRCA germline mutation. An estimated additional 15-20% of those affected with BC will have one or more first- and/or second-degree relatives with BC. Therefore, when these numbers are combined, familial BC risk accounts for approximately 20-25% of the total BC burden. However, because of the often limited information on family history in the etiologic assessment of BC, this may be an underestimate. Confounding factors include its phenotypic and genotypic heterogeneity, given the association of HBC with a plethora of differing cancer syndromes. Its most common occurrence is its association with ovarian cancer in the so-called hereditary breast-ovarian cancer syndrome due to BRCA1 and BRCA2 mutations. More rarely, it occurs in the Li-Fraumeni syndrome, caused by a p53 germline mutation, in which markedly early-onset BC is found in association with brain tumors, sarcomas, leukemia, lymphoma, malignant melanoma, and adrenal cortical carcinoma. Importantly, the age-adjusted incidence of BC in women in the United States fell sharply, by 6.7%, in 2003, when compared with the rate identified in 2002. We postulate that increasing knowledge about the genetics of BC may have partially contributed to the identification of high-risk patients who thereby may have benefited significantly from early diagnosis.
    Full-text · Article · Jan 2008 · The Breast Journal
Show more