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Biomedical subjects

Steven A Narod

Publications and source records attributed to Steven A Narod.

At least 91 records · Page 5Linked to original sources
PubMed2003

Single nucleotide polymorphism of the human kallikrein-2 gene highly correlates with serum human kallikrein-2 levels and in combination enhances prostate cancer detection.

PURPOSE: We examined the relationship between a mutant (T) for wild-type (C) allele substitution of the human kallikrein-2 gene (KLK2), circulating human kallikrein-2 (hK2) levels and prostate cancer risk. PATIENTS AND METHODS: We studied 1,287 consecutive men who underwent prostate biopsies because of an abnormal prostate-specific antigen level. Serum and DNA were obtained before biopsy. Cases were patients with cancer, and controls were patients with no cancer. The mutant and wild-type alleles of the KLK2 gene were designated as the T and C alleles, respectively. RESULTS: Of the 1,287 men, 616 had cancer, and 671 had no cancer. The overall distribution of the CC, CT, and TT KLK2 genotypes was 55.1%, 38.2%, and 6.8%, respectively. The median hK2 levels for men with the CC, CT, and TT genotypes were 0.24, 0.18, and 0.062 ng/mL and correlated with the genotypes, respectively (P =.0001). The adjusted odds ratios for prostate cancer for patients with the TT and CT genotypes compared with patients with the CC genotype, were 2.13 (95% confidence interval [CI], 1.3 to 3.5; P =.004) and 1.51 (95% CI, 1.2 to 2.0; P =.002), respectively. The adjusted odds ratio for prostate cancer for patients in the fourth quartile of hK2 compared with the first quartile was 4.33 (95% CI, 2.9 to 6.4; P =.0001). When combined, the adjusted odds ratio for having prostate cancer was 13.92 (95% CI, 6.6 to 29.2; P =.0001) for patients with high hK2 levels and at least one T allele. CONCLUSION: The C/T polymorphism of the KLK2 gene and circulating levels of hK2 are correlated and, in combination, are highly predictive for prostate cancer.

Adenocarcinoma↗
PubMed2003

Improved survival in women with BRCA-associated ovarian carcinoma.

BACKGROUND: The objective of this study was to determine the clinical characteristics, treatment response, and frequency of p53 overexpression in Ashkenazi Jewish women with hereditary ovarian carcinoma. METHODS: Seventy-one Jewish women with epithelial ovarian carcinoma (EOC) were tested for the three BRCA founder mutations using single-strand conformation polymorphism analysis, heteroduplex analysis, and protein truncation testing. Clinical and histopathologic data were reviewed retrospectively. In vitro chemoresistance was analyzed in 32 patients. Mutations of p53 were studied using immunohistochemical detection of p53 overexpression. RESULTS: Thirty-four of 71 Jewish patients with EOC (48%) had germline BRCA mutations (BRCA heterozygotes), including 22 BRCA1 mutations and 12 BRCA2 mutations. BRCA heterozygotes were younger compared with Jewish patients who had EOC without mutations (sporadic carcinoma; 50 years vs. 59 years, respectively; P = 0.01). BRCA1 heterozygotes were younger compared with BRCA2 heterozygotes (48 years vs. 57 years, respectively; P = 0.01). Histopathologic tumor features were similar; however, tumors with low malignant potential were seen only in women with sporadic carcinoma. Both groups had equivalent rates of surgical cytoreduction and similar median follow-up (72 months). BRCA heterozygotes had higher response rates to primary therapy compared with patients who had sporadic disease (P = 0.01). In vitro chemoresistance predicted tumor response to platinum chemotherapy correctly in BRCA heterozygotes (P = 0.0096). BRCA heterozygotes with advance-stage disease had improved survival compared with patients who had advanced stage sporadic carcinoma (91 months vs. 54 months, respectively; P = 0.046) and had a longer disease free interval (49 months vs. 19 months, respectively; P = 0.16). p53 overexpression was common in BRCA heterozygotes (80%). CONCLUSIONS: BRCA1 heterozygotes developed EOC at a younger age compared with BRCA2 heterozygotes and women who had sporadic ovarian carcinoma. BRCA heterozygotes had a better response to platinum chemotherapy compared with women who had sporadic disease, which may have contributed to their improved prognosis.

Adult↗
PubMed2003

Heterozygosity for the BLM(Ash) mutation and cancer risk.

Bloom syndrome is an autosomal recessive disorder whose characteristics include an increased risk for many types of cancers. In contrast to the homozygous mutations of Bloom syndrome, heterozygous carriers of BLM mutations may be at increased risk for developing colorectal cancer. We have screened 2,333 Jewish individuals, including 497 individuals with colorectal cancer, 125 with adenomatous polyps, 767 with noncolorectal cancers and 944 controls for the truncating BLM(Ash) founder mutation. The BLM(Ash) mutation was carried by 0.80% of individuals with colorectal neoplasia, 0.87% of those with any type of cancer and 0.85% of controls. In addition to case-control data, we found no evidence to support a significant relationship between increased cancer risk and heterozygous BLM(Ash) mutations with respect to age of cancer diagnosis, tumor multiplicity or family cancer history.

Aged↗
PubMed2003

Reproductive factors and ovarian cancer risk in Jewish BRCA1 and BRCA2 mutation carriers (United States).

OBJECTIVE: To determine whether oral contraceptive (OC) use, childbearing, breastfeeding and tubal ligation differ between ovarian cancer cases with and without a BRCA1/2 mutation. METHODS: A case-only study of 242 Jewish women with invasive epithelial ovarian cancer. Women were genotyped for three Ashkenazi founder mutations (185delAG and 5382insC in BRCA1 and 6174delT in BRCA2). We obtained data on OC use, childbearing, breastfeeding, gynecologic surgeries and other reproductive factors from each woman. We compared the frequencies of these risk factors in carriers and non-carriers using unconditional logistic-regression, controlling for other covariates. RESULTS: Among the 242 cases, 64 (26.4%) carried one of the BRCA1 founder mutations, and 31 (12.8%) carried the BRCA2 mutation. Although there were no differences in the percent of nulliparous women between carriers and non-carriers, parous BRCA1 carriers reported fewer live births than non-carriers (average of 2.1 versus 2.5 live births, OR = 0.61, 95% CI = 0.39-0.95, adjusted for age at diagnosis, tubal ligation and duration of OC use). Carriers and non-carriers did not differ in their history of breastfeeding, or in their lifetime use of OCs. BRCA1 carriers were more likely than non-carriers to have had a tubal ligation (25.0 versus 10.2%, OR = 3.67, 95% CI = 1.55-8.70, adjusted for age at diagnosis, number of live births and OC duration). CONCLUSIONS: In general, OC use, childbearing and breastfeeding do not differ between BRCA1/2 carriers and non-carriers with ovarian cancer. However, the effects of tubal ligation may differ between BRCA1 carriers and non-carriers.

Adult↗
PubMed2003

Breast cancer risk reduction associated with the RAD51 polymorphism among carriers of the BRCA1 5382insC mutation in Poland.

The observed heterogeneity of breast cancer risk among women who carry the same BRCA1 mutation suggests the existence of modifying environmental and genetic factors. The product of the RAD51 gene functions with BRCA1 and BRCA2 in the repair of double-stranded DNA breaks. To establish whether polymorphic variation of RAD51 modifies risk for hereditary breast cancer, we conducted a matched case-control study on 83 pairs of female carriers of the BRCA1 5382insC mutation. Cases consisted of women with breast cancer, and controls were women with the same mutation but who were unaffected. The frequency of the RAD51 135C variant allele was established in cases and controls using RFLP-PCR. The RAD51 135C allele was detected in 37% of unaffected and in 17% of affected BRCA1 carriers. Among 27 discordant matched pairs, the RAD51 135C allele was found in the healthy carrier on 22 occasions and in the affected carrier on only five occasions (odds ratio = 0.23; 95% confidence interval, 0.07-0.62; P = 0.0015). This finding suggests that RAD51 is a genetic modifier of breast cancer risk in BRCA1 carriers in the Polish population. It will be of interest to confirm this in other populations as well.

Adult↗
PubMed2003

The N314D polymorphism of galactose-1-phosphate uridyl transferase does not modify the risk of ovarian cancer.

It has been proposed that high levels of galactose consumption increase the risk of ovarian cancer. Galactose levels are determined, in part, by the galactose-1-phosphate uridyl transferase gene (GALT). The N314D allele of the GALT gene has been associated with low GALT activity and with an increased risk of ovarian cancer. We screened for the presence of the N314D GALT allele in 891 incident cases of epithelial ovarian cancer and in 364 unaffected female controls. No significant difference in the prevalence of the N314D allele was observed between the cases (18.1%) and the controls (18.7%). The odds ratio associated with the presence of one N314D allele was 0.94 (95% confidence interval (CI), 0.68-1.3; P = 0.70), and the odds ratio associated with two N314D alleles was 1.62 (95% CI, 0.34-7.7; P = 0.54). Subanalyses of the cases by histological type, by age, by ethnic group, by family history, and by BRCA1/2 mutation status did not reveal any significant associations. We conclude that the GALT N314D allele does not predispose to epithelial ovarian cancer.

Adult↗
PubMed2003

Androgen receptor gene polymorphism and breast cancer susceptibility in The Philippines.

Up to one-third of women with breast cancer have a family history of breast cancer, and approximately 5% of cases are attributed to mutations in high-risk breast cancer susceptibility genes, such as BRCA1 and BRCA2. It is believed that genes of lower penetrance, but of greater prevalence, may also modulate a woman's risk of breast cancer. We studied the association of breast cancer and the trinucleotide repeat polymorphism (CAGn) in exon 1 of the androgen receptor gene (AR) in 299 cases of breast cancer and in 229 hospital-based controls from The Philippines. Women for whom the mean length of the CAG repeat allele was < or = 25 units had approximately one-half of the risk of breast cancer compared with women with a mean repeat length of > or = 26 [odds ratio (OR), 0.47; 95% confidence interval (CI), 0.28-0.8). The association with breast cancer risk was particularly strong among older women (> or = 50 years; OR, 0.2; 95% CI, 0.04-0.94). The association was also observed for the longer of the two AR alleles; there was a 5% increase in breast cancer risk for each unit increase in CAG repeat number. These findings support the theory that short trinucleotide repeat genotypes of the AR gene protect against breast cancer.

Adult↗
PubMed2003

Comprehensive assessment of candidate genes and serological markers for the detection of prostate cancer.

We examined whether selected polymorphisms in 11 candidate genes and serum levels of insulin-like growth factor I (IGF-I) help predict the presence of prostate cancer among patients prescreened with prostate-specific antigen (PSA) and digital rectal exam (DRE). We studied 1031 consecutive men who underwent one or more prostate biopsies because of an elevated PSA level (>4 ng/ml) or an abnormal DRE. Eleven candidate genes were examined, including the androgen receptor, SRD5A2, CYP17, CYP3A4, vitamin D receptor, PSA, GST-T1, GST-M1, GST-P1, IGF-I, and IGF binding protein 3. We also measured serum IGF-I levels before biopsy. Of the 1031 men, 483 had cancer on any biopsy (cases) and 548 men had no cancer (controls). Age, ethnicity, total PSA, and DRE result were strongly predictive of the presence of prostate cancer. The mean IGF-I level for cases (119.4 ng/ml) was lower than for controls (124.4 ng/ml, P = 0.05) and were not predictive for the presence of prostate cancer. We found no associations between the androgen receptor, SRD5A2, CYP17, CYP3A4, vitamin D receptor, GST-M1, GST-P1, and IGF binding protein 3 genotypes and prostate cancer risk. The adjusted odds ratios for having prostate cancer for patients with the GST-T1 and IGF-I variant alleles were 1.64 (95% confidence interval, 1.1-2.4; P = 0.01) and 1.70 (95% confidence interval, 1.1-2.7; P = 0.02), respectively. Nine of 11 candidate genes were not significantly predictive for prostate cancer in a clinical setting. The GST-T1 and IGF-I polymorphisms demonstrated modest associations with prostate cancer risk. IGF-I levels were not helpful in identifying patients with prostate cancer at the time of biopsy.

Adult↗
PubMed2002

Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers.

BACKGROUND: Oral contraceptive use has been associated with an increase in the risk of breast cancer in young women. We examined whether this association is seen in women at high risk of breast cancer because they carry a mutation in one of two breast cancer susceptibility genes, BRCA1 and BRCA2. METHODS: We performed a matched case-control study on 1311 pairs of women with known deleterious BRCA1 and/or BRCA2 mutations recruited from 52 centers in 11 countries. Women who had been diagnosed with breast cancer were matched to control subjects by year of birth, country of residence, mutation (BRCA1 or BRCA2), and history of ovarian cancer. All study subjects completed a questionnaire about oral contraceptive use. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived by conditional logistic regression. All statistical tests were two-sided. RESULTS: Among BRCA2 mutation carriers, ever use of oral contraceptives was not associated with an increased risk of breast cancer (OR = 0.94, 95% CI = 0.72 to 1.24). For BRCA1 mutation carriers, ever use of oral contraceptives was associated with a modestly increased risk of breast cancer (OR = 1.20, 95% CI = 1.02 to 1.40). However, compared with BRCA1 mutation carriers who never used oral contraceptives, those who used oral contraceptives for at least 5 years had an increased risk of breast cancer (OR = 1.33, 95% CI = 1.11 to 1.60), as did those who used oral contraceptives before age 30 (OR = 1.29, 95% CI = 1.09 to 1.52), those who were diagnosed with breast cancer before age 40 (OR = 1.38, 95% CI = 1.11 to 1.72), and those who first used oral contraceptives before 1975 (OR = 1.42, 95% CI = 1.17 to 1.75). CONCLUSIONS: Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for 5 or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers are limited.

Adolescent↗
PubMed2002

Breast cancer risk perception among women who have undergone prophylactic bilateral mastectomy.

BACKGROUND: Prophylactic bilateral mastectomy is a preventive option for women who are at high risk of developing breast cancer. We compared the perceptions of breast cancer risk among women who had previously undergone prophylactic bilateral mastectomy with objective estimates of their breast cancer risk. METHODS: We asked 75 women in the Canadian province of Ontario who had undergone prophylactic bilateral mastectomy between 1991 and 2000 to provide a complete family history of the cancers that had occurred by the time of their surgery and to indicate their BRCA1 and BRCA2 gene mutation status. This information was used to generate estimates of each woman's risk for breast cancer by using the Gail model, the Claus model, and the BRCAPRO model. Sixty of the women also provided their own estimates of their lifetime risks of developing breast cancer before and after they had prophylactic mastectomy. Risk estimates were compared using Wilcoxon's signed-rank test and Pearson's product-moment correlation analysis. All statistical tests were two-sided. RESULTS: The women estimated that their lifetime risk of developing breast cancer before surgery was, on average, 76% (range = 20%-100%) and after surgery was 11.4% (range = 0%-60%). The mean estimated absolute risk reduction the women attributed to prophylactic mastectomy was 64.8%. The average computer-generated risk estimates were 59% for the 14 women who reported that they carried a BRCA1 or BRCA2 gene mutation and 17% for the other women (of whom 43 had a strong family history of breast cancer and 18 had a limited family history). Breast cancer risk was statistically significantly overestimated by all women except for the known BRCA1 and BRCA2 gene mutation carriers. CONCLUSION: Women who undergo prophylactic bilateral mastectomy have an exaggerated perception of their breast cancer risk before surgery. Formal genetic counseling and genetic testing may result in more accurate risk perceptions to guide women in choosing other preventive options.

Breast Neoplasms↗
PubMed2002

Contribution of BRCA1 and BRCA2 mutations to breast and ovarian cancer in Pakistan.

The population of Pakistan has been reported to have the highest rate of breast cancer of any Asian population (excluding Jews in Israel) and one of the highest rates of ovarian cancer worldwide. To explore the contribution that genetic factors make to these high rates, we have conducted a case-control study of 341 case subjects with breast cancer, 120 case subjects with ovarian cancer, and 200 female control subjects from two major cities of Pakistan (Karachi and Lahore). The prevalence of BRCA1 or BRCA2 mutations among case subjects with breast cancer was 6.7% (95% confidence interval [CI] 4.1%-9.4%), and that among case subjects with ovarian cancer was 15.8% (95% CI 9.2%-22.4%). Mutations of the BRCA1 gene accounted for 84% of the mutations among case subjects with ovarian cancer and 65% of mutations among case subjects with breast cancer. The majority of detected mutations are unique to Pakistan. Five BRCA1 mutations (2080insA, 3889delAG, 4184del4, 4284delAG, and IVS14-1A-->G) and one BRCA2 mutation (3337C-->T) were found in multiple case subjects and represent candidate founder mutations. The penetrance of deleterious mutations in BRCA1 and BRCA2 is comparable to that of Western populations. The cumulative risk of cancer to age 85 years in female first-degree relatives of BRCA1-mutation-positive case subjects was 48% and was 37% for first-degree relatives of the BRCA2-mutation-positive case subjects. A higher proportion of case subjects with breast cancer than of control subjects were the progeny of first-cousin marriages (odds ratio [OR] 2.1; 95% CI 1.4-3.3; P=.001). The effects of consanguinity were significant for case subjects with early-onset breast cancer (age <40 years) (OR=2.7; 95% CI 1.5-4.9; P=.0008) and case subjects with ovarian cancer (OR=2.4; 95% CI 1.4-4.2; P=.002). These results suggest that recessively inherited genes may contribute to breast and ovarian cancer risk in Pakistan.

Adult↗
PubMed2002

Prophylactic bilateral mastectomy: patterns of practice.

BACKGROUND: Many women who are at an elevated risk of developing breast carcinoma choose prophylactic mastectomy to decrease their risk. We conducted a population-based study to review the indications for, and patterns of practice of prophylactic mastectomy in Ontario, Canada, since 1991. METHODS: A medical chart review was conducted at 33 hospitals that were identified as having conducted at least one prophylactic mastectomy. All bilateral mastectomy patients with no diagnosis of invasive or in situ breast carcinoma were eligible. RESULTS: The number of prophylactic bilateral mastectomies performed varied from 6 to 19. The mean age of women undergoing prophylactic mastectomy was 43.5 years. Eighty percent of the women had prophylactic mastectomy performed because of a family history of breast carcinoma (89 of 99) or because of a known BRCA1 or BRCA2 mutation (10 of 99). Twenty percent of the women had no family history, but had the surgery for other benign breast conditions. Women with a family history of breast carcinoma were much more likely to have a total mastectomy (89%) than a subcutaneous mastectomy (11%). Sixty percent of the women had reconstructive surgery following mastectomy. CONCLUSIONS: Prophylactic mastectomy is not performed on a large scale. The introduction of genetic testing for BRCA1 and BRCA2 has the potential to change the patterns of practice for prophylactic mastectomy.

Adult↗
PubMed2002

Prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations.

BACKGROUND: Data concerning the efficacy of bilateral prophylactic oophorectomy for reducing the risk of gynecologic cancer in women with BRCA1 or BRCA2 mutations are limited. We investigated whether this procedure reduces the risk of cancers of the coelomic epithelium and breast in women who carry such mutations. METHODS: A total of 551 women with disease-associated germ-line BRCA1 or BRCA2 mutations were identified from registries and studied for the occurrence of ovarian and breast cancer. We determined the incidence of ovarian cancer in 259 women who had undergone bilateral prophylactic oophorectomy and in 292 matched controls who had not undergone the procedure. In a subgroup of 241 women with no history of breast cancer or prophylactic mastectomy, the incidence of breast cancer was determined in 99 women who had undergone bilateral prophylactic oophorectomy and in 142 matched controls. The length of postoperative follow-up for both groups was at least eight years. RESULTS: Six women who underwent prophylactic oophorectomy (2.3 percent) received a diagnosis of stage I ovarian cancer at the time of the procedure; two women (0.8 percent) received a diagnosis of papillary serous peritoneal carcinoma 3.8 and 8.6 years after bilateral prophylactic oophorectomy. Among the controls, 58 women (19.9 percent) received a diagnosis of ovarian cancer, after a mean follow-up of 8.8 years. With the exclusion of the six women whose cancer was diagnosed at surgery, prophylactic oophorectomy significantly reduced the risk of coelomic epithelial cancer (hazard ratio, 0.04; 95 percent confidence interval, 0.01 to 0.16). Of 99 women who underwent bilateral prophylactic oophorectomy and who were studied to determine the risk of breast cancer, breast cancer developed in 21 (21.2 percent), as compared with 60 (42.3 percent) in the control group (hazard ratio, 0.47; 95 percent confidence interval, 0.29 to 0.77). CONCLUSIONS: Bilateral prophylactic oophorectomy reduces the risk of coelomic epithelial cancer and breast cancer in women with BRCA1 or BRCA2 mutations.

Adult↗
PubMed2002

BRCA1 and BRCA2 mutations among breast cancer patients from the Philippines.

Age-adjusted incidence rates of breast cancer vary more than 10-fold worldwide, with the highest rates reported in North America and Europe. The highest breast cancer incidence rates in Southeast Asia have been reported for the Manila Cancer Registry in the Philippines, with an age-standardized rate of 47.7 per 100,000 per year. The possible contribution of hereditary factors to these elevated rates has not been investigated. We conducted a case-control study of 294 unselected incident breast cancer cases and 346 female controls from Manila, Philippines. Cases and controls were selected from women below the age of 65 undergoing evaluation at the PGH in Manila because of a suspicious breast mass. Molecular analysis identified 12 BRCA2 mutations and 3 BRCA1 mutations. We estimate the prevalence of BRCA mutations among unselected breast cancer cases in the Philippines to be 5.1% (95% CI: 2.6-7.6%), with a prevalence of 4.1% (95% CI: 1.8-6.4%) for BRCA2 mutations alone. The BRCA2 4265delCT and 4859delA mutations were found in 2 and 4 unrelated cases, respectively; haplotype analysis confirmed that these, and the BRCA1 5454delC mutation, are founder mutations. BRCA2 mutations were also found in 2 of 346 controls (0.6%; 95% CI: 0.2-1.4%). Compared with non-carrier cases, the cumulative risk of breast cancer for first-degree relatives of mutation carriers was 24.3% to age 50, compared with <4% for first-degree relatives of non-carrier cases (RR = 6.6; 95% CI: 2.6-17.2; p= 7.5 x 10(-6)). Our data suggest that penetrance of BRCA mutations is not reduced in the Philippines. Germline mutations in the BRCA2 gene contribute more than mutations BRCA1 to breast cancer in the Philippines, due in large part to the presence of 2 common founder mutations.

Adult↗
PubMed2002

Cancer incidence in a population of Jewish women at risk of ovarian cancer.

PURPOSE: To evaluate the incidence and clinical characteristics of ovarian and other cancers in a cohort of women at risk of developing ovarian cancer. PATIENTS AND METHODS: The Gilda Radner Ovarian Cancer Detection Program in Los Angeles, CA, was established in 1991 to study the efficacy of screening in the early detection of ovarian cancer. We present findings from a historical cohort of 290 Jewish women who were offered BRCA testing for three common founder mutations (BRCA1 185delAG and 5382insC and BRCA2 6174delT). RESULTS: In 10 years, 17 cancers were observed (1,111 per 100,000 per year), including six breast and eight ovarian or related cancers. A high proportion of cancers of peritoneal origin was observed. The majority (86%) of women with incident breast or ovarian/peritoneal cancer carried a mutation in the BRCA1 gene. The overall cancer incidence among carriers of mutations in the BRCA1 gene was estimated to be 5,450 per 100,000 per year, corresponding to a cumulative incidence of 47.5% at 10 years. In contrast, the cumulative incidence of cancer among noncarriers was 2.5% (P < 10(-8)). After adjustment for sampling, the risks to BRCA1 mutation carriers at 10 years were estimated to be 21% for ovarian/peritoneal/tubal cancer, 16% for breast cancer, and 36% for all cancers. CONCLUSION: The excess risk of breast and ovarian cancer in Jewish women with a family history of ovarian cancer is largely attributable to mutations in BRCA1. Intensive surveillance by use of CA-125 and ultrasound does not seem to be an effective means of diagnosing early-stage ovarian cancer in this high-risk cohort.

Adult↗