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Biomedical subjects

P Rozen

Publications and source records attributed to P Rozen.

At least 19 recordsLinked to original sources
PubMed2006

Can quantification of faecal occult blood predetermine the need for colonoscopy in patients at risk for non-syndromic familial colorectal cancer?

BACKGROUND: Patients at risk for non-syndromic (Lynch or polyposis) familial colorectal neoplasia undergo colonoscopic surveillance at intervals determined by clinically ascertained protocols. The quantitative immunochemical faecal occult blood test for human haemoglobin is specific and sensitive for significant colorectal neoplasia (cancer or advanced adenomatous polyp). AIM: To determine immunochemical faecal occult blood test efficacy for identifying significant neoplasia in at-risk patients undergoing elective colonoscopy. METHODS: We retrospectively identified consecutive at-risk patients who provided three immunochemical faecal occult blood tests before colonoscopy. Quantitative haemoglobin analysis was performed by the OC-MICRO automated instrument using the 100 ng Hb/mL threshold to determine positivity. RESULTS: In 252 at-risk patients undergoing colonoscopy; five had cancer, 14 an advanced adenoma and 46 a non-advanced adenoma. The immunochemical faecal occult blood test was positive in 31 patients (12.3%). Sensitivity, specificity, positive and negative predictive values for cancer were: 100%, 90%, 16% and 100%, and for all significant neoplasia: 74%, 93%, 45% and 98%. With 88% fewer colonoscopies, all colorectal cancers and 74% of all significant neoplasia would have been identified by this one-time immunochemical faecal occult blood test screening. CONCLUSIONS: A sensitive, non-invasive, interval screening test might be useful to predetermine the need for colonoscopy in this at-risk population and minimize unnecessary examinations. This favourable retrospective evaluation will be extended to a prospective study.

Aged↗
PubMed2006

A quantitative immunochemical faecal occult blood test is more efficient for detecting significant colorectal neoplasia than a sensitive guaiac test.

BACKGROUND: The sensitive guaiac faecal occult blood test, Haemoccult SENSA (HOS; Beckman Coulter, Fullerton, CA, USA), is our standard screening test for significant colorectal neoplasia. We evaluated an automatically-developed, quantified human haemoglobin immunochemical faecal test, OC-MICRO (Eiken Chemical Co., Tokyo, Japan), to improve test specificity and so reduce the colonoscopy burden. AIM: To compare guaiac faecal occult blood test and immunochemical faecal test diagnostic efficacy and costs for identifying significant neoplasia. METHODS: Colonoscopies were performed on patients who prepared three daily guaiac faecal occult blood tests with or without immunochemical faecal tests. RESULTS: Total colonoscopy was performed on 151 subjects who prepared both guaiac and immunochemical faecal tests (group 1) and the positive predictive values (PPV) were also compared to those of 162 subjects undergoing colonoscopy for positive guaiac faecal occult blood tests (group 2). In group 1, comparative sensitivity, specificity, and PPVs for significant neoplasia with guaiac faecal occult blood test were 75%, 34%, and 12% (PPV, 18% for group 2) and with immunochemical faecal test were 75%, 94% and 60% (P < 0.01 for specificity). The number of colonoscopy examinations needed to detect a significant neoplasm because of positive faecal occult blood tests was six to eight with HOS and two with OC-MICRO at 21-31% the cost of evaluating a positive guaiac faecal occult blood test. CONCLUSION: An immunochemical faecal test maintains the high sensitivity of guaiac faecal occult blood test, but significantly reduces the colonoscopy burden and screening costs.

Aged↗
PubMed2004

Cancer of the gastrointestinal tract: early detection or early prevention?

Gastrointestinal cancer is a major medical and economic burden worldwide. Oesophageal and gastric cancers are most common in the non-industrialized countries, while colorectal cancer is the predominant gastrointestinal malignancy in westernized countries. Their aetiology is mainly related to correctable and preventable lifestyle habits; namely diet (including obesity), physical activity, alcohol and tobacco intake, and sanitation. Prevention and/or treatment of Helicobacter pylori infection would significantly reduce the prevalence of gastric cancer. Screening for cancer, its early detection and treatment requires medical facilities, endoscopic expertise and a major investment of national financial resources. This is only feasible in affluent industrialized countries such as Japan for gastric cancer, some western countries for oesophageal and colorectal cancer. Only population screening for colorectal cancer has been proven feasible and cost-beneficial.

Chemoprevention↗
PubMed2003

A sensitive guaiac faecal occult blood test is less useful than an immunochemical test for colorectal cancer screening in a Chinese population.

BACKGROUND: Colorectal cancer screening by guaiac faecal occult blood test has been shown to reduce the incidence and mortality of colorectal cancer in Western populations. The optimal faecal occult blood test, whether guaiac or immunochemical, for colorectal cancer screening in the Chinese population remains to be defined. AIM: To compare the performance characteristics of a sensitive guaiac-based faecal occult blood test (Hemoccult SENSA) and an immunochemical faecal occult blood test (FlexSure OBT) in a Chinese population referred for colonoscopy. METHODS: One hundred and thirty-five consecutive patients who were referred for colonoscopy and who met the study inclusion criteria took samples for the two faecal occult blood tests simultaneously from three successive stool specimens, with no dietary restrictions. All tests were developed and interpreted by a single experienced technician who was blind to the clinical diagnosis. The sensitivity, specificity and positive predictive value for the detection of colorectal adenomas and cancers were estimated for the two tests. RESULTS: The sensitivity, specificity and positive predictive value for the detection of significant colorectal neoplasia (adenomas > or = 1.0 cm and cancers) were 91%, 70% and 18% for Hemoccult SENSA and 82%, 94% and 47% for FlexSure OBT. The specificity and positive predictive value were significantly higher for FlexSure OBT than for Hemoccult SENSA (P < 0.001 and P = 0.016, respectively). Combining the positive results from both faecal occult blood tests did not improve the accuracy. CONCLUSION: The positive predictive value of the immunochemical faecal occult blood test for the detection of significant colorectal neoplasia was 29% better than that of the sensitive guaiac-based test. This may relate to the Chinese diet and requires further study. The poor specificity of the sensitive guaiac-based test, without dietary restriction, makes it less useful for colorectal cancer screening in a Chinese population.

Adult↗
PubMed2003

An ancestral Ashkenazi haplotype at the HMPS/CRAC1 locus on 15q13-q14 is associated with hereditary mixed polyposis syndrome.

The putative locus for hereditary mixed polyposis syndrome (HMPS) in a large family of Ashkenazi descent (SM96) was previously reported to map to chromosome sub-bands 6q16-q21. However, new clinical data, together with molecular data from additional family members, have shown 6q linkage to be incorrect. A high-density genomewide screen for the HMPS gene was therefore performed on SM96, using stringent criteria for assignment of affection status to minimize phenocopy rates. Significant evidence of linkage was found only on a region on chromosome 15q13-q14. Since this region encompassed CRAC1, a locus involved in inherited susceptibility to colorectal adenomas and carcinomas in another Ashkenazi family (SM1311), we determined whether HMPS and CRAC1 might be the same. We found that affected individuals from both families shared a haplotype between D15S1031 and D15S118; the haplotype was rare in the general Ashkenazi population. A third informative family, SM2952, showed linkage of disease to HMPS/CRAC1 and shared the putative ancestral haplotype, as did a further two families, SMU and RF. Although there are probably multiple causes of the multiple colorectal adenoma and cancer phenotype in Ashkenazim, an important one is the HMPS/CRAC1 locus on 15q13-q14.

Adenomatous Polyposis Coli↗
PubMed2003

A prospective study of the clinical, genetic, screening, and pathologic features of a family with hereditary mixed polyposis syndrome.

In 1997, hereditary mixed polyposis syndrome (HMPS) was described in an Ashkenazi pedigree having colorectal polyps with mixed histology and risk for colorectal cancer (CRC). The mutation is now localized to 15q13-14. Since 1980, compliant relatives of an HMPS family were seen annually, tested genetically, and had colonoscopy offered every 1 to 2 yr from age 20 yr. The Israeli pedigree has 37 members (17 clinically affected by CRC or polyps), and seven of 13 available relatives entered our screening program. The others, followed-up elsewhere, provided clinical information. Half of our screened group had rectal bleeding; others were asymptomatic. Colonoscopy, performed a mean of four times, identified polyps in all seven patients (mean age 28 yr). Polyps were removed and included juvenile adenomas, mixed juvenile adenomas, hyperplastic polyps, mixed hyperplastic adenomas, serrated adenomas, and tubular adenomas. None of our screened patients developed CRC or extracolonic neoplasia. Linkage analysis localized their mutation to 15q13-14. This high-penetrance founder mutation so far is described only in Ashkenazim. The CRC pathway seems to be through juvenile and hyperplastic polyps. Mutation identification will aid screening for and evaluation of HMPS prevalence in Jewish and non-Jewish populations. Meanwhile, a cancer pedigree and correct classification of polyps will identify HMPS families. They require early and frequent colonoscopy, polypectomy, and elective extensive colectomy when indicated.

Adenomatous Polyposis Coli↗
PubMed2001

Germline mutations in BMPR1A/ALK3 cause a subset of cases of juvenile polyposis syndrome and of Cowden and Bannayan-Riley-Ruvalcaba syndromes.

Juvenile polyposis syndrome (JPS) is an inherited hamartomatous-polyposis syndrome with a risk for colon cancer. JPS is a clinical diagnosis by exclusion, and, before susceptibility genes were identified, JPS could easily be confused with other inherited hamartoma syndromes, such as Bannayan-Riley-Ruvalcaba syndrome (BRRS) and Cowden syndrome (CS). Germline mutations of MADH4 (SMAD4) have been described in a variable number of probands with JPS. A series of familial and isolated European probands without MADH4 mutations were analyzed for germline mutations in BMPR1A, a member of the transforming growth-factor beta-receptor superfamily, upstream from the SMAD pathway. Overall, 10 (38%) probands were found to have germline BMPR1A mutations, 8 of which resulted in truncated receptors and 2 of which resulted in missense alterations (C124R and C376Y). Almost all available component tumors from mutation-positive cases showed loss of heterozygosity (LOH) in the BMPR1A region, whereas those from mutation-negative cases did not. One proband with CS/CS-like phenotype was also found to have a germline BMPR1A missense mutation (A338D). Thus, germline BMPR1A mutations cause a significant proportion of cases of JPS and might define a small subset of cases of CS/BRRS with specific colonic phenotype.

Abnormalities, Multiple↗
PubMed2001

Calcium supplements interact significantly with long-term diet while suppressing rectal epithelial proliferation of adenoma patients.

BACKGROUND: Calcium supplements to the western-style diet may reduce the risk for colorectal neoplasia. Using rectal epithelial proliferation (REP) measurements as a biomarker of response to intervention, the authors evaluated the effects of 1-year calcium supplementation in adenoma patients and its possible interactions with the patients' dietary and lifestyle habits. METHODS: Consenting adenoma patients, without a family history of colorectal neoplasia, were randomly selected to receive 3.75 g calcium carbonate (1.5 g Ca2+) daily or to receive no treatment. All had their long-term dietary and lifestyle habits assessed and their REP labeling index (LI) evaluated before and at end of follow-up. The change in LI was compared between groups, and statistical associations were examined between mean nutrient consumption and treatment effect and between lifestyle and treatment effect. RESULTS: Fifty-two adenoma patients (33 treated and 19 untreated) completed intervention and follow-up. There were no significant differences between study groups in age, weight, cigarette smoking, or medication use. The LI decreased in 58% of calcium-intervened patients and in only 26% of nonintervened patients (P = 0.04); the mean LI x 100 (+/- standard deviation) of the former fell from 5.04 +/- 1.93 to 4.54 +/- 1.58, and rose from 4.32 +/- 1.58 to 4.93 +/- 1.58 in the latter (P = 0.04). A lower fat, a higher carbohydrate, fiber, or fluid intake each interacted with the calcium supplementation to decrease the LI (P = 0.02, 0.001, 0.02, and 0.08, respectively). CONCLUSIONS: Long-term calcium supplements significantly suppressed REP in adenoma patients, and long-term dietary habits contributed to this effect. Patient diet should be assessed when researchers use REP as a biomarker in calcium chemoprevention studies. Study results indicated that relevant dietary counseling may be useful in addition to calcium supplements in persons at increased risk for colorectal neoplasia.

Adenoma↗
PubMed2001

Familial adenomatous polyposis at the Tel Aviv Medical Center: demographic and clinical features.

UNLABELLED: Familial adenomatous polyposis (FAP) is an uncommon, but widespread genetic disorder that develops multiple colonic adenomatous polyps and, if untreated, can lead to large bowel cancer. Little is known about its occurrence and characteristics in the Israeli population. AIMS: To evaluate FAP prevalence, phenotypic manifestations and compliance for diagnosis and follow-up in our registry. METHODS: Since 1993 approximately one-half of FAP patients in Israel have been seen and followed-up by us before and/or after colectomy. They and their families were encouraged to have mutation analysis, genetic and/or endoscopic screening. RESULTS: 37 pedigrees were identified, including 2 non-Jewish. The Jewish ethnic distribution was similar to that of the general population and the point prevalence rate estimated as 28.4/one million Jewish inhabitants. There were 461 first-degree relatives at-risk for FAP. Genetic screening was completed and successful in 28 pedigrees (87.5%), and 73 FAP patients entered the registry. Marked intra- familial phenotypic variations with minimal disease manifestation were noted in 11 patients belonging to 4 pedigrees. Cancer occurred in 15.1% (11 patients), in 10 before FAP diagnosis or during follow- up elsewhere, but one non-compliant patient developed duodenal cancer. One other patient died from a massive, neglected, intra- abdominal desmoid. Compliance for evaluation and follow-up of pedigree members and individual FAP patients was inadequate in 29% and 27%, respectively. CONCLUSIONS: FAP occurs in the Israeli Jewish population at the expected rate, but is inadequately recognized in non-Jews. The inadequate compliance for screening and post-surgical follow-up needs to be addressed by educating the public, health care workers and Health Insurers.

Adenomatous Polyposis Coli↗
PubMed2000

Comparative screening with a sensitive guaiac and specific immunochemical occult blood test in an endoscopic study.

BACKGROUND: HemoccultSENSA (HOS), the sensitive guaiac fecal occult blood test (FOBT) for colorectal neoplasia, is faulted for its low specificity, which might be improved by substituting or adding FlexSure OBT (FS), the immunochemical test for human hemoglobin. (Both tests are manufactured by Beckman-Coulter Inc., Primary Care Diagnostics, Palo Alto, CA.) The authors compared both FOBTs in an endoscopic study to determine which FOBT to recommend for a population-screening program. METHODS: Both FOBTs, without dietary restrictions, were prepared by 1410 screenees or nonbleeding symptomatic patients (3%). All underwent colonoscopy (51.8%) or flexible sigmoidoscopy (if asymptomatic and both FOBTs were negative). RESULTS: HOS sensitivity for significant neoplasia, cancers, or adenomas >/= 1 cm (20 cases) was similar to that of FS (50% vs. 35%, not significant). However, HOS specificity was lower (95% vs. 99%, confidence interval (CIs) 94-96 vs. 98-99, P < 0.05). In those 11 cases in which both HOS and FS were positive, specificity for significant neoplasia was 100% but sensitivity decreased to 25% (less than HOS alone, P < 0.05). HOS was more sensitive than FS for any neoplasia (55 cases), including adenomas < 1 cm (35% vs. 18%, CIs 22-47 vs. 8-28, P < 0.05), but less specific (96% vs. 99%, CIs 95-97 vs. 98-100, P < 0.05). CONCLUSIONS: Guaiac HOS, which does not require dietary restrictions, is significantly more sensitive for any colorectal neoplasm than the immunochemical FS; it identifies more adenomas with a specificity that is low but acceptable for population screening.

Adenoma↗