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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Familial risk of colon cancer is a commonly encountered issue, involving both rare inherited syndromes of colon cancer and common familial clustering of cases. The genes that give rise to the rare syndromes of FAP and HNPCC are now known and current research is addressing the cellular mechanisms of these genes and the proper application of genetic testing in families with one of the syndromes. Common familial clustering of cases appears to arise from an interaction of mildly to moderately severe inherited susceptibility factors with certain environmental factors to give rise to adenomatous polyps and then finally colorectal cancer. Research in this area involves identification of these purportedly more common susceptibility genes, and determination of how each interacts with environmental factors to give rise to polyps and cancer. Optimal application of varying degrees of familial risk to screening strategies is also being determined.
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PMID:Familial association. 1070 79

Hereditary colorectal cancer syndromes account for about 7% of all colorectal carcinomas. The most frequent form is Hereditary Nonpolyposis Colorectal Cancer (HNPCC). Identification, cloning and sequence analysis of the predisposing genes enables identification of mutation carriers and non-mutation carriers, respectively. These genetic informations can be used in an individually tailored clinical surveillance program and may ultimately result in standard preventive surgical treatment. In classical FAP the surgical standard is performing a restorative proctocolectomy. It is still unclear now, if this procedure should be modified in attenuated forms (colectomy with ileorectostomy). Due to a high rate of synchronous and metachronous carcinomas a subtotal colectomy in the case of first colon cancer seems to be indicated in HNPCC patients. A proctocolectomy or a restorative proctocolectomy should be weighed in case of carcinomas in the lower rectum. These procedures should be performed under the precondition of identification of the pathogenic germline mutation in the patient, only. In addition, a synchronous prophylactic hysterectomy with oophorectomy should be recommended postmenopausal gene carriers. Intensive counseling of the patient should proceed these preventive procedures involving surgeons, gastroenterologists, geneticists, molecular biologists, gynecologists, physicians and psychologists. It is recommended to have patients treated exclusively in specialized centers. Currently, six interdisciplinary centers for cancer surveillance and early diagnosis in hereditary colorectal cancer are being sponsored in Germany by the Deutsche Krebshilfe since 1999. In the future clinical studies have to be conducted to evaluate the efficacy of extended colorectal resections versus efficacy of surveillance and conventional resections according to general oncological principles.
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PMID:[Surgery of hereditary colorectal carcinoma]. 1092 42

Nonpolyposis Colorectal Cancer (HNPCC) accounts for about 5% of all colorectal cancers and is the most frequent familial form; familial adenomatous polyposis coli accounts for about 1%. Prerequisitive for individually tailored surveillance is the identification of the pathogenic germline mutation. In classical FAP, surgical standard is a restorative proctocolectomy while in HNPCC there is no surgical standard other than standard oncological resection due to missing evidence. In HNPCC, prophylactic colectomy before the onset of the first colorectal cancer is not recommended. Main arguments for the extension of the resection in the case of the first colorectal carcinoma in HNPCC are the rate of metachronous colorectal carcinomas of 40-45% in a 10-year interval and rapid tumor progression. In HNPCC, in the case of first colon cancer a subtotal colectomy seems to be indicated. A proctocolectomy or, if indicated, a restorative proctocolectomy may be considered in the case of carcinomas in the lower rectum. These considerations should be evaluated in a prospective clinical trial. Counselling, molecular diagnosis and surgery in patients with hereditary colorectal cancers should only be performed in interdisciplinary centers.
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PMID:[Hereditary colorectal carcinomas - reflection on preventive surgery]. 1160 Aug 6

The main progress in surgical oncology regarding colonic cancer has been made by standardizing the mode of resection: En block resection of the tumor-bearing colon segment together with the draining lymph nodes, including the lymph nodes at the origin of the respective main vessel, is mandatory. Minimal invasive surgery is an option for resection, however, results of ongoing multicenter trials have to clarify the situation. Adjuvant therapy is used for patients in stage III, who are not included in studies. Since quality of surgery has a major influence on prognosis, this factor also needs to be taken into account when judging the impact of adjuvant therapy. New chemotherapeutic agents have been proven to be valid for palliative and probably also for adjuvant treatment. Prophylactic surgery is routine for patients with ulcerative colitis and FAP, the benefit for patients with HNPCC has to be further evaluated. New knowledge on the individual prognosis might optimize treatment; most probably this will be accomplished by detection of minimal residual disease. The impact of the sentinel node concept in colon cancer is unclear. New progress will be possible by an approach adapted to the individual problem together with accumulating and linking experience and knowledge.
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PMID:[Progress in oncological visceral surgery: colon carcinoma]. 1182 72

The clinical differentiation between hereditary nonpolyposis colorectal cancer (HNPCC) and attenuated familial adenomatous polyposis (AFAP) is very difficult. The 62-yr-old proband presented with duodenal adenocarcinoma. His history of subtotal colectomy for colon cancer, the rarity of duodenal adenocarcinoma in the general population, and his family history of colon cancer made us suspect that he might have FAP. We investigated this family by obtaining medical records and performing gene analysis. The proband had only 10 adenomatous colon polyps when he underwent subtotal colectomy for the cancer, so classic FAP was excluded. His family history included rectal cancer in his brother at 69 yr of age, colon cancer in his mother at 75 yr, and colon cancer in one maternal cousin at 42 yr. Three months after we started to study this family, the proband's 32-yr-old son presented with rectal cancer. His family fulfilled the Amsterdam criteria for HNPCC, but AFAP could not be excluded. Upon gene testing, the proband was negative for APC gene germline mutation, which made AFAP highly unlikely. Moreover, high microsatellite instability (MSI) was detected in his adenomas and cancer tissues. The fulfillment of Amsterdam criteria, the exclusion of FAP and AFAP, and the high MSI established the diagnosis of HNPCC in this family. We also summarize the differences between FAP, AFAP, and HNPCC; extend the graphic description of the MSI mechanism; and propose a diagnostic strategy for HNPCC.
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PMID:Challenge in the differentiation between attenuated familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer: case report with review of the literature. 1213 43

Remarkable progress has been accomplished in understanding the molecular basis of genetic colon cancer syndromes including FAP and HNPCC, and their variants; of sporadic colon cancer; and of the rare hamartomatous polyp syndromes. This molecular progress now has to be translated into clinical progress in molecular diagnosis, and in pharmacologic therapy for colonic polyps and cancers. It is hoped that such progress will impact on the frequency and mortality of this very common and frequently fatal cancer.
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PMID:The molecular and genetic basis of colon cancer. 1251 Apr 61

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.
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PMID:Risk stratification for colorectal cancer and implications for screening. 1601 42

Patients suffering from familial adenomatosis polyposis develop multiple pre-malignant gastrointestinal polyps and are at high risk of developing colon cancer. In addition extra-intestinal manifestations are observed frequently. The combination of extra-intestinal manifestations and familial adenomatosis polyposis is named Gardner's syndrome. An early diagnosis of this disease is important because it could mean a better prognosis for the patient. This review describes the oral and maxillofacial symptoms of FAP, and its potential implications for dental treatment.
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PMID:[Oral and maxillofacial manifestations of familial adenomatosis polyposis. Gardner's syndrome]. 1618 13

Overexpression of cyclooxygenase-2 (COX-2) is observed early in colon cancer. Treatments with COX-2-specific NSAIDs have been shown to reduce polyp size and polyp number in FAP patients with a predisposition to colorectal adenoma and cancer. However, the use of COX-2-specific NSAIDs in colon cancer patients has recently revealed increased cardiovascular risks. These harmful side effects may be the result of COX-dependent and/or COX-independent mechanisms. RNA interference (RNAi) is a method of post-transcriptional gene silencing intrinsic to cells. This study employed RNAi to specifically knockdown endogenous COX-2 expression in the HT-29 colon cancer cell line, and to observe the apoptotic response as well as 15-hydroxyprostaglandin dehydrogenase (15-PGDH) expression levels. Following treatment with a COX-2 siRNA, we demonstrated a significant knockdown at the protein level of 57% as compared to a non-silencing siRNA control. Protein results were corroborated by concurrent decrease in COX-2 mRNA levels following the same treatment regimen. Despite previous studies using NSAID treatment to implicate COX-2 involvement in apoptosis, we did not observe any alteration in Bcl-2 expression and Caspase-3 activation following COX-2 knockdown in these cells. 15-PGDH, a physiological antagonist of COX-2 in its catabolism of PGE2, showed a modest but significant induction in response to COX-2 knockdown. The precise role of COX-2 in apoptosis and PGE2 regulation remains unclear; however, having shown that down-regulation of endogenous levels of COX-2 can be achieved in colon cancer by RNAi, this strategy should prove to be a valuable tool in revealing the specific function of COX-2 in tumourigenesis.
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PMID:Cyclooxygenase-2 knockdown by RNA interference in colon cancer. 1639 11

Recent advances in laparoscopic surgery have made it possible to perform restorative proctocolectomy (RP) for ulcerative colitis (UC) or familial adenomatous polyposis (FAC). However, most of these procedures are performed as two-stage operations with the creation of diverting ileostomy. Furthermore, they are performed with a small abdominal incision from 4 to 8 cm in length. We describe the first case of ulcerative colitis that underwent a single-stage completely laparoscopic restorative proctocolectomy without an abdominal incision. The patient also underwent lymph node dissection since he had a sigmoid colon cancer. The postoperative course was uneventful and the functional outcome was satisfactory. Considering the improved cosmetic as well as functional results achieved by this procedure, the present technology can be applied for selected patients, especially young UC or FAP patients needing RP who seek for a superior cosmetic result.
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PMID:One-stage completely laparoscopic restorative proctocolectomy for ulcerative colitis complicated with sigmoid colon cancer--a case report. 1696 40


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