Familial Risk Of Colorectal Cancer Research Articles

Colorectal cancer mortality in first-degree relatives of early-onset colorectal cancer cases.

Estimates of familial colorectal cancer risks are useful in genetic counseling and as a guide to determining entry into screening programs and trials of chemoprevention. Furthermore, they provide an insight into the contribution of the known colorectal cancer genes to the familial risk of the disease. There is a paucity of data about the familial colorectal cancer risk associated with early-onset disease outside the recognized cancer predisposition syndromes. This was a retrospective cohort study. The parents and siblings of 205 patients with colorectal cancer aged less than 55 years at diagnosis were studied for mortality and cancer incidence. The overall standardized mortality ratio of colorectal cancer compared with the Northern Irish population was 3.54 (95 percent confidence interval, 2.59-4.79). There was some evidence that a family history of colorectal cancer is associated with a greater risk of colon (4.16; 95 percent confidence interval, 2.83-5.91) rather than rectal cancer (2.62; 95 percent confidence interval, 1.43-4.40). Risks in parents (2.54; 95 percent confidence interval, 1.45-3.72) were lower than in siblings (6.15; 95 percent confidence interval, 3.90-9.23). First-degree relatives of patients with early-onset disease are at a marked increase in risk. There is evidence that risks vary depending on the type of affected relative and by the site of colorectal cancer. This information should be considered in formulating screening strategies.

Family history and colorectal cancer screening: a survey of physician knowledge and practice patterns

OBJECTIVES: Risk stratification is essential to effective implementation of colorectal cancer (CRC) screening strategies. The objectives of this study were to assess and compare the current knowledge and practice patterns of gastroenterologists and primary care physicians regarding familial risk of CRC. METHODS: We conducted a survey of regional gastroenterologists and a sample of university- and community-based primary care physicians. The survey instrument assessed physician knowledge of screening recommendations and current practices for individuals with family histories of CRC, adenomatous polyps (APs), familial adenomatous polyposis (FAP), and hereditary nonpolyposis cancer (HNPCC). The instrument also elicited data about familial risk assessment, documentation, and notification of at-risk family members. RESULTS: Thirty-five gastroenterologists (65%) and 58 primary care physicians (92%) completed the survey. Most gastroenterologists and primary care physicians (85% vs 72%) chose age 40 as the appropriate age to begin screening for a family history of CRC, but relatively few (37% vs 36%) recommended screening at age 40 for a family history of APs. Gastroenterologists were significantly more likely to recommend screening for FAP at puberty (80% vs 27%, p < 0.001) and for HNPCC at age 25 (73% vs 50%, p = 0.04). Colonoscopy was the preferred screening strategy by both groups for family histories of CRC (97%), HNPCC (97%), and APs (77%); primary care physicians also preferred colonoscopy for family histories of CRC (72%) and HNPCC (76%) but flexible sigmoidoscopy plus fecal occult blood testing for a family history of APs (38%). Gastroenterologists were more likely to recommend genetic testing for persons at risk of FAP (91% vs 71%, p = 0.03) and HNPCC (72% vs 57%, p = 0.18), routinely inquire about a family history of CRC or APs (93% vs 63%, p < 0.001), and recommend notification of at-risk first-degree relatives with family histories of CRC (94% vs 55%, p < 0.001) or AP (53% vs 6%, p < 0.001). CONCLUSION: Although gastroenterologists are more likely than primary care physicians to elicit a family history of colorectal neoplasia and implement appropriate screening strategies, overall compliance with recommended guidelines and notification of at-risk relatives are suboptimal. Novel approaches for improving awareness of the available screening guidelines are needed.

A systematic review and meta-analysis of familial colorectal cancer risk

OBJECTIVE: The aim of this study was to identify published studies quantifying familial colorectal cancer (CRC) risks in first-degree relatives of CRC and colorectal adenoma (CRA) cases and, through a meta-analysis, obtain more precise estimates of familial risk according to the nature of the family history and type of neoplasm. METHODS: Twenty-seven case-control and cohort studies were identified, which reported risks of CRC in relatives of CRC cases and nine, which reported the risk of CRC in relatives of CRA cases. Pooled estimates of risk for various categories of family history were obtained by calculating the weighted average of the log relative risk estimates from studies. RESULTS: The pooled estimates of relative risk were as follows: a first-degree relative with CRC 2.25 (95% CI = 2.00–2.53), colon 2.42 (95% CI = 2.20–2.65), and rectal 1.89 (95% CI = 1.62–2.21) cancer; parent with CRC 2.26 (95% CI = 1.87–2.72); sibling with CRC 2.57 (95% CI = 2.19–3.02); more than one relative with CRC 4.25 (95% CI = 3.01–6.08); relative diagnosed with CRC before age 45, 3.87 (95% CI = 2.40–6.22); and a relative with CRA 1.99 (95% CI = 1.55–2.55). CONCLUSIONS: Individuals with a family history of CRC and CRA have a significantly elevated risk of developing CRC compared with those without such a history. Risks are greatest for relatives of patients diagnosed young, those with two or more affected relatives, and relatives of patients with colonic cancers.

A systematic review and meta-analysis of familial colorectal cancer risk.

The aim of this study was to identify published studies quantifying familial colorectal cancer (CRC) risks in first-degree relatives of CRC and colorectal adenoma (CRA) cases and, through a meta-analysis, obtain more precise estimates of familial risk according to the nature of the family history and type of neoplasm. Twenty-seven case-control and cohort studies were identified, which reported risks of CRC in relatives of CRC cases and nine, which reported the risk of CRC in relatives of CRA cases. Pooled estimates of risk for various categories of family history were obtained by calculating the weighted average of the log relative risk estimates from studies. The pooled estimates of relative risk were as follows: a first-degree relative with CRC 2.25 (95% CI = 2.00-2.53), colon 2.42 (95% CI = 2.20-2.65), and rectal 1.89 (95% CI = 1.62-2.21) cancer; parent with CRC 2.26 (95% CI = 1.87-2.72); sibling with CRC 2.57 (95% CI = 2.19-3.02); more than one relative with CRC 4.25 (95% CI = 3.01-6.08); relative diagnosed with CRC before age 45, 3.87 (95% CI = 2.40-6.22); and a relative with CRA 1.99 (95% CI = 1.55-2.55). Individuals with a family history of CRC and CRA have a significantly elevated risk of developing CRC compared with those without such a history. Risks are greatest for relatives of patients diagnosed young, those with two or more affected relatives, and relatives of patients with colonic cancers.

Hyperplastic polyposis syndrome conters an increassed personal and familial risk of adenomas and colorectal cancer

Hyperplastic polyposis syndrome conters an increassed personal and familial risk of adenomas and colorectal cancer

Hyperplastic polyposis syndrome conters an increassed personal and familial risk of adenomas and colorectal cancer

Hyperplastic polyposis syndrome conters an increassed personal and familial risk of adenomas and colorectal cancer

Does hereditary nonpolyposis colorectal cancer explain the observed excess risk of colorectal cancer associated with family history?

Several studies have found an increased risk of colorectal cancer associated with a family history of colorectal cancer. Some studies, although not all, have also suggested that family history of colorectal cancer may be a risk factor for adenomatous polyps. Hereditary nonpolyposis colorectal cancer is a known genetic syndrome predisposing to colorectal cancer. The hypothesis of this paper is that the preponderance of the genetic or familial risk for colorectal cancer in the United States is mediated by hereditary nonpolyposis colorectal cancer. To test this hypothesis, I have incorporated what is known about hereditary nonpolyposis colorectal cancer into a genetic model that generates probabilities of family clustering of colorectal cancer. Using this model, which assumes that all familial risk for colorectal cancer is due to hereditary nonpolyposis colorectal cancer, the expected relative risks for colorectal cancer (and adenomas) associated with given types of family histories were calculated. The relative risks predicted by the model fairly closely matched the results found in the literature, especially those reported from a large cohort study. As observed in several studies, the model predicts that relative risks decrease sharply with age. In contrast to the elevated risk for colorectal cancer, the model predicts no elevated risk for adenomas associated with family history of colorectal cancer.

Lack of communication about familial colorectal cancer risk associated with colorectal adenomas

Lack of communication about familial colorectal cancer risk associated with colorectal adenomas

Lack of communication about familial colorectal cancer risk associated with colorectal adenomas (United States).

Sufficient evidence has accumulated to suggest that the first-degree relatives of patients diagnosed with colorectal adenomas before the age of 60 are at increased risk of colorectal cancer. The principal objective of this study was to assess the extent to which channels of communication exist between physicians, patients and their at-risk first-degree relatives regarding both familial risk and screening recommendations. A telephone survey was conducted among 79 patients (age < or = 60 years) with newly diagnosed colorectal adenomas. Information regarding patient demographics, awareness of familial risk, physician recommendations, and extent of communication with family members about their risk status and need for screening was ascertained. Forty-four (56%) of the 79 eligible subjects completed the survey. Only 18 (41%) responders were aware that their first-degree relatives were at increased risk of colorectal cancer, and the majority claimed to have gained their awareness through sources other than their physicians. Only five (28%) of the 18 knowledgeable patients notified their at-risk relatives of their status, and only two (11%) communicated the need for screening. This survey demonstrates poor communication about familial colorectal cancer risk associated with colorectal adenomas, and highlights the need for novel strategies to both promote awareness and facilitate screening of at-risk relatives.

Right-sided adenomas and familial risk for colorectal cancer. Preliminary data

Right-sided adenomas and familial risk for colorectal cancer. Preliminary data

Congenital hypertrophy of the retinal pigment epithelium and mandibular osteomata as markers in familial colorectal cancer

Congenital hypertrophy of the retinal pigment epithelium (CHRPE) and multiple mandibular osteomata are markers of familial adenomatous polyposis (FAP). We have assessed their prevalence in non-polyposis familial colorectal neoplasia. Multiple mandibular osteomata were present in 1/29 (3%) patients with familial colorectal neoplasia. CHRPE was present in 11/33 (33%) patients with familial colorectal neoplasia compared with 3/36 (8%) with sporadic disease (P = 0.01) and 4/32 (12.5%) control subjects (P = 0.04). Seven patients with familial colorectal neoplasia had multiple areas of CHRPE compared with one with sporadic disease (P = 0.02) and one control subject (P = 0.02). There was no obvious correlation between calculated familial colorectal cancer risk and the presence of multiple areas of CHRPE. A proportion of patients with familial colorectal cancer have a marker found in FAP and may therefore have a constitutional genetic defect, at least in part responsible for their cancer, making them an interesting group for genetic study. Ophthalmoscopy may contribute to risk assessment in familial colorectal cancer.

Characteristics of familial colon cancer in a large population data base.

Early age onset and proximal colonic location are two specific characteristics of colon cancer which have been used clinically to assess the risk that an individual case is of familial rather than sporadic origin. This practice derives from the observation that these characteristics are typical of the rare, nonpolyposis inherited colorectal cancer syndromes. This study examines these two characteristics in cases of common colon cancer to determine whether they actually distinguish individuals at increased risk for familial colorectal cancer. Familial clusters of colon cancer in the Utah Population Data Base were examined. Common colon cancers were found to cluster excessively in families; however, the measure of familial clustering for distal colonic cases was increased to the same degree as proximal colonic cases. Early age onset was likewise not a distinguishing factor of familial cases. These results suggest that factors other than those that predispose to the rare syndromes are important in determining familial risk for common colon cancers, and that the absence of these two clinical features should not suggest the absence of familial risk of colorectal cancer.