Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: UMLS:C0009402 (
colorectal cancer
)
53,228
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
There is evidence that aspirin--and apparently other NSAIDs--may be protective agents against cancer in the gastrointestinal tract. These effects are particularly well documented in the colon and rectum. Even considered in isolation, the observational data regarding colorectal neoplasia are quite strong, and the reality of a protective effect is buttressed by clinical trial data showing that aspirin prevents sporadic adenomas. Furthermore, the NSAIDs sulindac celecoxib have actually led to the regression of existing colorectal polyps in patients with
FAP
. Clearly, NSAIDs have the potential to suppress carcinogenesis in the large bowel. Observational data suggesting inverse associations of NSAIDs with cancers of the stomach and esophagus have emerged from several case-control studies and a few cohort analyses. In some studies the findings display features often associated with causal relationships, for example decreasing risks with increasing doses or duration of use. Nonetheless, the data currently do not support a secure conclusion that NSAIDs protect against these malignancies. The relevant data are not nearly as extensive as those for the colorectum, and case-control investigation of these upper gastrointestinal sites may be particularly delicate. It is conceivable that early symptoms of cancer (or of pre-invasive lesions) may have discouraged NSAID use in the cancer patients, creating the appearance of a protective association of the drugs with the risk of these malignancies. More extensive observational data particularly from cohort studies would be desirable to confirm the existing findings and clarify the doses and durations of use required for an effect. Clinical trial investigation might also be practical for pre-neoplastic endpoints, or--in carefully selected populations--perhaps with cancer as the focus. There are only relatively limited data available regarding the effect of NSAIDs on cancer of the pancreas. However, the studies that have investigated this malignancy have reported indications that NSAIDs may have a protective effect. The effects of NSAIDs on cancers outside the gastrointestinal tract are not clear. Some investigations suggest that NSAID use, particularly aspirin, is inversely associated with risk of cancers of the breast or ovary, but several well-done studies have not seen these associations, and the observations could have been due to bias or confounding. Findings regarding prostate cancer are similarly conflicting. The urinary tract is one organ system in which several studies have reported an increased cancer risk in association with NSAID use. Nonetheless, the effects remain unclear. There is only limited available information regarding carcinoma of the bladder, and no firm conclusions can be drawn at this point. More extensive data have been generated regarding the effect of NSAIDs--largely salicylates--on renal cell carcinoma or cancer or the renal pelvis and ureter. Although some studies have reported increased risks, there are also findings suggesting no association. It is particularly difficult for observational studies to ascertain with confidence the true effects of aspirin because of the suspected relationship of these cancers with use of phenacetin and perhaps acetaminophen. Further data--particularly from careful and large cohort studies--would be important to clarify these issues. As a body of research, the findings discussed here from epidemiological studies and clinical trials have begun to clarify the effect of NSAIDs on carcinogenesis in various organs in humans. There is clear potential for protective effects at several anatomic sites. Even for the colorectum, however, it is probably premature to now begin to use these drugs widely for cancer prevention. To reach that point, a weighing of the risks and benefits of the drugs needs to be made, together with a judgement regarding the benefits of alternative means of prevention. For
colorectal cancer
, for example, aspirin may provide only limited benefit over regular colonoscopy [95, 96]. Nonetheless, with the increased understanding of the clinical effects of NSAIDs on cancer, the development of effective chemoprevention with these drugs appears to be a real possibility.
...
PMID:Epidemiology of non-steroidal anti-inflammatory drugs and cancer. 1279 46
Due to the development of more effective medications, those infected with HIV are living longer. Consequently, more tumors and infections have been added to the AIDS-defining criteria in the last decade. Our aim was to review the occurrence and clinical course of colorectal (CR) malignancies in HIV infected/AIDS patients from a single institution. A retrospective review of HIV/AIDS patients with colorectal malignant tumors was undertaken. We included adult patients, with ELISA and Western blot test positive for HIV, and primary malignant tumors located in the colon or rectum. Malignant neoplasms of the anus were excluded for the purposes of this study. Twelve patients (9 males and 3 females), mean age 41 years, were identified with the following neoplasm: 6 adenocarcinomas (ACA), 5 non-Hodgkin lymphomas (NHL), and 1 small-cell carcinoma. Intravenous drug abuse was the main risk factor for HIV. No patient had identified risk factors for colorectal neoplasm. Five out of six patients with ACA had metastatic disease at the time of diagnosis. One patient with stage II ACA developed early liver metastases after colonic resection. Seven out of 12 patients underwent surgery. Six (85.7%) of these sustained postoperative complications, primarily wound infection. The overall survival in our series was dismal, averaging 20 months. For NHL average survival was 29 months, and 12 months for CR-ACA. This is the largest series of cases of
colorectal cancer
in the HIV/AIDS patient population published in the English language and the largest number of colorectal ACA reported in this unique population. Early in our experience, tumors frequently found in immunoincompetent patients were detected (NHL). More recently, we have only treated patients with colorectal ACA; none of them had no risk factors for
colorectal cancer
(family history, IBD,
FAP
, HNPCC). These patients developed tumors at earlier ages and were diagnosed at an advanced stage. Therefore, these tumors may be associated with the grade of immunosuppression induced during the course of the HIV infection and with a tumorigenic effect of the HIV on the colonic epithelium. Consequently, a high index of suspicion when evaluating chronic abdominal complaints in such patients is warranted. The use of the new antiretroviral therapy regimens should be further evaluated to know its impact in the survival.
...
PMID:Colorectal malignancies in HIV-positive patients. 1462 61
Colorectal carcinoma
is a growing medical problem. Prevention represents the most effective approach for reducing the incidence and mortality. Population-based screening with subsequent colonoscopic polypectomy is the most common strategy. There are, however, other approaches increasing the portfolio of available measures. These include the special care of groups with an increased risk for
CRC
based on family or medical history and various chemopreventive strategies. Family history is a simple method to identify a person with increased risk of
CRC
. There are two groups of familial
CRC
: monogenetic hereditary syndromes such as
FAP
and HNPCC and hereditary predispositions with sporadic
CRC
. Recent advances in genetic tests and tailored surveillance strategies are able to decrease the morbidity and mortality in these groups. Therefore a wider recognition of family history as risk indicator of
CRC
should be encouraged. Chemoprevention is a very promising concept for both primary and secondary prevention of
CRC
. Although definite evidence is difficult to provide a number of studies suggest a role for nutritional interventions and/or chemoprevention with plant phytosterols, fiber, selenium, calcium, probiotics or COX2 inhibitors as putative chemopreventive strategies. (Tab. 4, Ref. 70.).
...
PMID:Is there any role for prevention strategies for colorectal cancer other than population-based screening? 1553 13
Tumour necrosis factor-related apoptosis-inducing ligand (TRAIL) and antibodies against TRAIL receptors death receptor 4 (DR4) and death receptor 5 (DR5) are under investigation for cancer therapy. To study the potential application of these agents, the expression of DR4 and DR5 were studied immunohistochemically in colorectal adenomas and carcinomas from patients with sporadic disease (n=74 and 56, respectively), familial adenomatous polyposis (
FAP
, n=41 and 4, respectively) and hereditary non-polyposis
colorectal cancer
(HNPCC, n=50 and 21, respectively). BAX, which is frequently mutated in tumours with high-frequency microsatellite instability (MSI-H) may play a role in sensitivity to TRAIL. Therefore, MSI-H carcinomas (n=42, of which 27 sporadic and 15 HNPCC) were analysed for apoptotic activity, assessed by M30 immunoreactivity, and BAX mutations. Most adenomas from all three patient groups expressed DR4 and DR5. Most carcinomas expressed DR4, except for six cases, all with mucinous histology. All carcinomas, including mucinous carcinomas, showed DR5 expression. BAX mutations were found in 6/42 MSI-H cancers with similar apoptotic indices and expression of DR4, DR5 and TRAIL in BAX mutant and wild-type cases. Since most sporadic and hereditary colorectal neoplasms express DR4 and DR5, targeting of these receptors may be a potential prevention or treatment strategy.
...
PMID:Expression of tumour necrosis factor-related apoptosis-inducing ligand death receptors in sporadic and hereditary colorectal tumours: potential targets for apoptosis induction. 1591 Dec 44
Biallelic germline mutations in the base excision repair gene MYH have been shown to predispose to a proportion of multiple colorectal adenomas and cancer. To evaluate the contribution of MYH mutations to non-
FAP
, non-HNPCC familial
colorectal cancer
, 84 unrelated Swedish individuals affected with
colorectal cancer
from such families were screened for germline mutations in the coding sequence of the gene. None of the cases was found to carry any pathogenic sequence change. We then determined the prevalence of the two most common pathogenic MYH mutations found in Caucasians, Y165C and G382D, in 450 Swedish sporadic
colorectal cancer
cases and 480 Swedish healthy controls. The frequency of both variants in Swedish cases and controls was similar to those previously reported. In addition, we found that previously unknown sequence variations at the position of amino acid 423 (R423Q, R423P, and R423R) appear to occur more frequently in cases than in controls (p = 0.02), a finding that warrants future studies.
...
PMID:Germline mutations in the MYH gene in Swedish familial and sporadic colorectal cancer. 1594 55
In addition to the well-recognized syndromes described (
FAP
, HNPCC) clusters of colorectal cancers occur in families much more often than would be expected by chance. This familial clustering in about 10-20% of colorectal cancers has implications for screening because the immediate family members of a patient with apparent sporadic
colorectal cancer
have a twofold to threefold increased risk of the disease. The magnitude of the risk depends on the age at diagnosis of the index case, the degree of kinship of the index case to the at-risk case, and the number of affected relatives. In addition to screening the easily identifiable high-risk groups such as
FAP
and HNPCC, care should be taken to recognize intermediate-risk patients and to provide them with appropriate screening recommendations. Because the molecular basis and the natural history of these intermediate-risk patients are largely unknown, screening recommendations are as yet more empirical. If a person has a first degree relative with colon cancer, average risk colon cancer screening is recommended, but starting at age 40 years. The decreased age is given because the risk at age 40 for those with an affected first-degree relative is similar to the risk at age 50 for the general population. An individual with two first-degree relatives affected with colon cancer or one first-degree relative diagnosed under the age of 60 y should have colonoscopy beginning at age 40, or 10 years younger than the earliest case in the family. Colonoscopy should be repeated every five years if negative. An even stronger family history of colon cancer syndromes of colon cancer should suggest the consideration of one of the inherited syndromes.
...
PMID:Risk stratification for colorectal cancer and implications for screening. 1601 42
HNPCC and
FAP
are inherited diseases with a lifetime risk of
colorectal cancer
(
CRC
) of 80-100% in gene carriers. Disease-causing mutations have been identified in the APC gene at
FAP
and in MMR genes at HNPCC. In
FAP
-patients, screening has reduced the prevalence of
CRC
by 55%, and the survival rate has improved considerably. For HNPCC-patients, 77% of CRCs found by screening were Duke' A or B, and survival after
CRC
has improved significantly since 1990. Continuous central registration in the HNPCC and Polyposis registers is recommended to ensure identification of high-risk families and evaluate the effect of screening.
...
PMID:[Hereditary colorectal cancer]. 1626 67
Autoregulatory growth control of adenomatous polyps in the colon and rectum is an important factor in the success of sphincter-sparing surgical resections. It is the basis for the coexistence of billions of somatic cells in multicellular organisms. Similar to normal mucosa, adenomatous polyps in the colorectum show autoregulatory growth control in their tissues. This applies whether they are differentiated or undifferentiated. In most cases, their growth and expansion is controlled throughout life. While colorectal adenomas have malignant potential, their transformation to cancerous lesions is exceedingly rare (e.g., in familial polyposis, or
FAP
, with a prevalence of only one in 10,000). It has been hypothesized that "fully developed adenomas" frequently are a prestage of
colorectal cancer
. However, convincing evidence on a molecular level that this so-called adenoma-carcinoma sequence indeed occurs in vivo is lacking. In contrast, there is good evidence that colorectal carcinogenesis is a microevolutionary process and that the irrevocable loss of autoregulatory growth control is one of its features. The most prominent homing area for
colorectal cancer
is the rectum. If the rectum is resected, metachronous cancer occurs only very rarely. The most distal quarter of the rectum is cloacal in origin and a pivotal structure for anorectal continence. It should be preserved whenever a more proximal location of the tumor makes this possible. These conclusions are based on our extensive case series and observations extending over several decades.
...
PMID:[Autoregulatory growth control of adenomatous polyps and carcinogenesis in the colorectal region. Basics of tumor surgery Part I]. 1706 70
Colonic polyps most commonly present with rectal bleeding in children. The isolated juvenile polyp is the most frequent kind of polyp identified in children. 'Juvenile' refers to the histological type of polyp and not the age of onset of the polyp. Adolescents and adults with multiple juvenile polyps are at a significant risk of intestinal cancer. The challenge for adult and pediatric gastroenterologists is determining the precise risk of
colorectal cancer
in patients with juvenile polyposis syndrome. Attenuated familial adenamatous polyposis (AFAP) can occur either by a mutation at the extreme ends of the adenomatous polyposis coli gene or by biallelic mutations in the mutY homologue (MYH) gene. The identification of MYH-associated polyposis as an autosomal recessive condition has important implications for screening and management strategies. Adult and pediatric gastroenterologists need to be aware of the underlying inheritance patterns of polyposis syndromes so that patients and their families can be adequately evaluated and managed. Colonic polyps, including isolated juvenile polyps, juvenile polyposis syndrome,
FAP
, AFAP and MYH-associated polyposis, are discussed in the present review.
...
PMID:Colonic polyps in children and adolescents. 1743 12
Some of the APC negative
FAP
and AFAP cases have recently been found to be attributable to MYH associated polyposis (MAP). MAP is an autosomal recessive syndrome associated with 5-100 colorectal adenomas and caused by mutation in the MYH gene. Here, we screened for germline MYH mutations in 82 APC-mutation-negative probands with classical and attenuated familial adenomatous polyposis using the denaturing high performance liquid chromatography (DHPLC) method in combination with sequencing. Altogether 12 previously reported changes and four novel genetic alterations, mostly in intronic sequences, were identified. The results revealed the presence of biallelic germline MYH mutations in two patients. These patients were compound heterozygotes for two of the most common germline mutations c.494 A>G (p.Y165C); c.1,145 G>A (p.G382D). These variants are established to be associated with adenomatous polyposis and
colorectal cancer
. No novel pathogenic mutation has been identified in our study.
...
PMID:Mutation analysis of the MYH gene in unrelated Czech APC mutation-negative polyposis patients. 1752 38
<< Previous
1
2
3
4
5
6
7
8
9
Next >>