Population differences in familial adenomatous polyposis may be an expression of geographic differences in APC mutation pattern.
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Adenomatous Polyposis Coli↗
Biomedical subjects
Henry T Lynch
Publications and source records attributed to Henry T Lynch.
Familial B-cell chronic lymphocytic leukemia: analysis of cytogenetic abnormalities, immunophenotypic profiles, and immunoglobulin heavy chain gene usage.
B-cell chronic lymphocytic leukemia (B-CLL) is a heterogeneous disease that may exhibit familial clustering. We examined the cytogenetic, immunophenotypic, and VH gene usage characteristics of a family with B-CLL affecting 7 members in 3 generations. Interphase fluorescence in situ hybridization studies identified an acquired deletion of chromosome 13q14 in the leukemic cells of 6 affected members, accompanied by deletion 14q32 or trisomy 12 in 2 cases. VH gene analysis demonstrated clonal rearrangements of the VH3 gene family in 5 cases and of VH2 genes in 1 case. All 6 cases were mutated in VH2 or VH3. Two cases had a second VH1 family gene rearrangement that was unmutated. Flow cytometry performed on 5 cases showed the typical B-CLL immunophenotype; all were CD38-, but 3 expressed ZAP-70. Our findings support previous observations that familial and sporadic B-CLL cases are biologically similar and suggest that familial clusters will be useful for studying pathogenetic events in B-CLL.
Adult↗
CHEK2 mutation and hereditary breast cancer.
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Breast Neoplasms↗
The risk of endometrial cancer in women with BRCA1 and BRCA2 mutations. A prospective study.
OBJECTIVE: To evaluate the risk of endometrial cancer in women who carry a deleterious mutation in the BRCA1 or BRCA2 genes. PATIENTS AND METHODS: Women known to carry a BRCA1 or BRCA2 mutation, aged 45 to 70, were identified from an international registry and were followed prospectively. A total of 857 women completed a baseline questionnaire and one or more follow-up questionnaires. Study subjects were followed until diagnosis of endometrial cancer, ovarian cancer, death or the date of completion of the last questionnaire. The expected number of endometrial cancers was calculated using age and country-specific incidence rates. RESULTS: After an average follow-up period of 3.3 years, six women were diagnosed with endometrial cancer, compared to 1.13 cancers expected (SIR=5.3, p=0.0011). Four of these six patients used tamoxifen in the past. The risk among women who were never exposed to tamoxifen treatment was not significantly elevated (SIR=2.7, p=0.17), but among the 226 participants who had used tamoxifen (220 as treatment and six for the primary prevention of breast cancer) the relative risk for endometrial cancer was 11.6 (p=0.0004). CONCLUSION: The main contributor to the increased risk of endometrial cancer among BRCA carriers is tamoxifen treatment for a previous breast cancer. The risk and benefits of prophylactic hysterectomy should be discussed with women with a BRCA mutation considering tamoxifen therapy.
Adult↗
Risk of colon cancer in hereditary non-polyposis colorectal cancer patients as predicted by fuzzy modeling: Influence of smoking.
AIM: To investigate whether a fuzzy logic model could predict colorectal cancer (CRC) risk engendered by smoking in hereditary non-polyposis colorectal cancer (HNPCC) patients. METHODS: Three hundred and forty HNPCC mismatch repair (MMR) mutation carriers from the Creighton University Hereditary Cancer Institute Registry were selected for modeling. Age-dependent curves were generated to elucidate the joint effects between gene mutation (hMLH1 or hMSH2), gender, and smoking status on the probability of developing CRC. RESULTS: Smoking significantly increased CRC risk in male hMSH2 mutation carriers (P < 0.05). hMLH1 mutations augmented CRC risk relative to hMSH2 mutation carriers for males (P < 0.05). Males had a significantly higher risk of CRC than females for hMLH1 non smokers (P < 0.05), hMLH1 smokers (P < 0.1) and hMSH2 smokers (P < 0.1). Smoking promoted CRC in a dose-dependent manner in hMSH2 in males (P < 0.05). Females with hMSH2 mutations and both sexes with the hMLH1 groups only demonstrated a smoking effect after an extensive smoking history (P < 0.05). CONCLUSION: CRC promotion by smoking in HNPCC patients is dependent on gene mutation, gender and age. These data demonstrate that fuzzy modeling may enable formulation of clinical risk scores, thereby allowing individualization of CRC prevention strategies.
Adaptor Proteins, Signal Transducing↗
Salpingo-oophorectomy and the risk of ovarian, fallopian tube, and peritoneal cancers in women with a BRCA1 or BRCA2 Mutation.
CONTEXT: Women with BRCA1 or BRCA2 mutation are often advised to undergo preventive oophorectomy. The effectiveness of this intervention has not been prospectively evaluated in a large cohort. OBJECTIVES: To estimate the incidence of ovarian, fallopian tube, and primary peritoneal cancer in women who carry a deleterious mutation in BRCA1 or BRCA2. To estimate the reduction in risk of these cancers associated with a bilateral prophylactic salpingo-oophorectomy. DESIGN, SETTING, AND PARTICIPANTS: Women known to carry a BRCA1 or BRCA2 mutation were identified from an international registry between 1992 and 2003. A total of 1828 carriers at 1 of 32 centers in Canada, the United States, Europe, and Israel completed questionnaires at baseline and follow-up. Participants were observed from the date of study entry until: diagnosis of ovarian, fallopian tube, or peritoneal cancer; death; or the date of the most recent follow-up. INTERVENTION: Participants were divided into women who had undergone bilateral prophylactic oophorectomy and those who had not. MAIN OUTCOME MEASURE: The incidence of ovarian, peritoneal, and fallopian tube cancer was determined by survival analysis. The risk reduction associated with prophylactic salpingo-oophorectomy was evaluated by a time-dependent survival analysis, adjusting for covariates. RESULTS: After a mean follow-up of 3.5 years, 50 incident ovarian, fallopian tube, and peritoneal cancer cases were reported in the cohort. Of the 1828 women, 555 (30%) underwent a bilateral prophylactic salpingo-oophorectomy prior to study entry, 490 (27%) underwent the procedure after entering the study, and 783 (43%) did not undergo the procedure. There were 32 incident cancers diagnosed in women with intact ovaries (1015/100,000 per year). Eleven cancer cases were identified at the time of prophylactic oophorectomy and 7 were diagnosed following prophylactic oophorectomy (217/100,000 per year). The estimated cumulative incidence of peritoneal cancer is 4.3% at 20 years after oophorectomy. The overall (adjusted) reduction in cancer risk associated with bilateral oophorectomy is 80% (multivariate hazard ratio = 0.20; 95% confidence interval, 0.07-0.58; P = .003). CONCLUSION: Oophorectomy is associated with reduced risk of ovarian and fallopian tube cancer in high-risk women, although there is a substantial residual risk for peritoneal cancer in BRCA1 and BRCA2 mutation carriers following prophylactic salpingo-oophorectomy.
Adult↗
Age-dependent morphological alterations of human ovaries from populations with and without BRCA mutations.
OBJECTIVE: From analysis of pre-cancer ovarian tissues obtained from prophylactic oophorectomies, several studies reported the increased ovarian morphological changes in high-risk ovaries, but whether these morphological changes are associated with BRCA1/BRCA2 genotypes or are cancer precursors is controversial. Here, we have investigated a recent collection of ovaries from prophylactic oophorectomies and control ovaries from surgeries due to other non-ovarian-related cancer or non-neoplastic diseases to determine if ovarian morphological changes relate to BRCA1/2 genotypes or reproductive history. METHODS: We assembled a panel of archived ovarian tissues: 52 ovarian tissue blocks were from prophylactic oophorectomies of a high-risk (HR) population; 66 ovaries were from surgeries due to non-ovarian-related diseases, referred to as normal-risk (NR) group. The morphology of ovarian tissues was examined, and morphological changes including papillomatosis, invaginations, inclusion cysts, and epithelial stratification were assessed in a blinded fashion. RESULTS: No statistically significant difference in frequency of these histolopathologic features was found between HR and NR groups. However, inclusion cysts and deep invaginations were found much more commonly in women age 45-54 of either HR or NR groups. CONCLUSIONS: This study suggests that no significant increase in the presence of non-neoplastic ovarian morphological changes is associated with BRCA1/BRCA2 mutations. Rather, the frequency of these histological features, especially inclusion cysts, may associate with age or menopausal status. We propose that ovulatory and perimenopausal gonadotropin stimulation produces ovarian morphological changes, and these histological features may promote the transformation of genetically compromised epithelial cells in the development of ovarian cancer.
Age Factors↗
Spontaneous and therapeutic abortions and the risk of breast cancer among BRCA mutation carriers.
INTRODUCTION: BRCA1 and BRCA2 mutation carriers are at increased risk for developing both breast and ovarian cancer. It has been suggested that carriers of BRCA1/2 mutations may also be at increased risk of having recurrent (three or more) miscarriages. Several reproductive factors have been shown to influence the risk of breast cancer in mutation carriers, but the effects of spontaneous and therapeutic abortions on the risk of hereditary breast cancer risk have not been well studied to date. METHODS: In a matched case-control study, the frequencies of spontaneous abortions were compared among 1,878 BRCA1 mutation carriers, 950 BRCA2 mutation carriers and 657 related non-carrier controls. The rates of spontaneous and therapeutic abortions were compared for carriers with and without breast cancer. RESULTS: There was no difference in the rate of spontaneous abortions between carriers of BRCA1 or BRCA2 mutations and non-carriers. The number of spontaneous abortions was not associated with breast cancer risk among BRCA1 or BRCA2 mutation carriers. However, BRCA2 carriers who had two or more therapeutic abortions faced a 64% decrease in the risk of breast cancer (odds ratio = 0.36; 95% confidence interval 0.16-0.83; p = 0.02). CONCLUSION: Carrying a BRCA1 or BRCA2 mutation is not a risk factor for spontaneous abortions and spontaneous abortions do not appear to influence the risk of breast cancer in carriers of BRCA1 or BRCA2 mutations. However, having two or more therapeutic abortions may be associated with a lowered risk of breast cancer among BRCA2 carriers.
Abortion, Spontaneous↗
Prophylactic surgery to reduce the risk of gynecologic cancers in the Lynch syndrome.
BACKGROUND: Women with the Lynch syndrome (hereditary nonpolyposis colorectal cancer) have a 40 to 60 percent lifetime risk of endometrial cancer and a 10 to 12 percent lifetime risk of ovarian cancer. The benefit of prophylactic gynecologic surgery for women with this syndrome has been uncertain. We designed this study to determine the reduction in the risk of gynecologic cancers associated with prophylactic hysterectomy and bilateral salpingo-oophorectomy in women with the Lynch syndrome. METHODS: Three hundred fifteen women with documented germ-line mutations associated with the Lynch syndrome were identified. Women who had undergone prophylactic hysterectomy (61 women) and women who had undergone prophylactic bilateral salpingo-oophorectomy (47 women) were matched with mutation-positive women who had not undergone the procedure in question (210 women for the analysis of endometrial cancer and 223 for the analysis of ovarian cancer). Women who had undergone prophylactic surgery and their matched controls were followed from the date of the surgery until the occurrence of cancer or until the data were censored at the time of the last follow-up visit. RESULTS: There were no occurrences of endometrial, ovarian, or primary peritoneal cancer among the women who had undergone prophylactic surgery. Endometrial cancer was diagnosed in 69 women in the control group (33 percent), for an incidence density of 0.045 per woman-year, yielding a prevented fraction (the proportion of potential new cancers prevented) of 100 percent (95 percent confidence interval, 90 to 100 percent). Ovarian cancer was diagnosed in 12 women in the control group (5 percent), for an incidence density of 0.005 per woman-year, yielding a prevented fraction of 100 percent (95 percent confidence interval, -62 to 100 percent). CONCLUSIONS: These findings suggest that prophylactic hysterectomy with bilateral salpingo-oophorectomy is an effective strategy for preventing endometrial and ovarian cancer in women with the Lynch syndrome.
Adult↗
American founder mutation for Lynch syndrome. Prevalence estimates and implications.
BACKGROUND: Recently, a new founder mutation, an exon 1-6 deletion in a mismatch repair gene (MMR), MSH2, in nine kindreds with Lynch syndrome was reported. In 3 of the kindreds this mutation was traced by genealogy through 11-12 generations to a common founder, and thus termed the American Founder Mutation (AFM). Since then, 13 additional 'unrelated' kindreds with AFM were detected by a recently designed single polymerase chain reaction. This test might serve as first-line screening for Lynch syndrome mutations, provided AFM was prevalent, which is assessed in the current study. METHODS: The number of current AFM carriers and the incidence of Lynch syndrome caused by AFM were estimated based on population growth of mutation carriers derived from genealogy data. For cross-checking, its annual incidence was also estimated based on published epidemiology data. RESULTS: There are 18,981 (5th and 95th percentiles, 6038 and 34,466, respectively) expected current AFM carriers, or 160 (range 51-290) Lynch syndrome cases diagnosed per year due to AFM estimated based on genealogy data. The incidence estimate closely overlaps with that based on published epidemiology data, which is 114-400 cases per year. CONCLUSIONS: A large number of AFM carriers are likely to exist in the U.S., which harbors significant implications for cancer control. Given the ease of detection, testing for AFM not only among members of the existing AFM families, but also among all patients with Lynch syndrome in the U.S. is proposed.
Colorectal Neoplasms, Hereditary Nonpolyposis↗
Pathologic features of endometrial carcinoma associated with HNPCC: a comparison with sporadic endometrial carcinoma.
BACKGROUND: Endometrial carcinoma is a common malignancy in hereditary nonpolyposis colorectal carcinoma (HNPCC). Like colon carcinoma, endometrial carcinoma is diagnosed at an earlier age in women with HNPCC. In contrast to colon carcinoma, the pathologic features of endometrial carcinoma in HNPCC have not been studied in detail. It was the purpose of this study to pathologically characterize a series of HNPCC associated endometrial carcinomas. METHODS: Fifty women with HNPCC and endometrial carcinoma were analyzed from four different hereditary cancer registries. H&E stained slides and pathology reports were reviewed for clinically important pathologic features of endometrial carcinoma. These results were compared with those for two different groups of sporadic endometrial carcinoma--women younger than age 50 years (n = 42) and women of all ages with tumors demonstrating microsatellite instability (MSI-high) secondary to methylation of MLH1 (n = 26). RESULTS: Nearly one-fourth of HNPCC patients in this study had endometrial tumors with pathologic features that would require adjuvant therapy after hysterectomy. There was a trend toward the HNPCC patients having more nonendometrioid tumors; all of these patients were carriers of MSH2 mutations. Such nonendometrioid tumors were extremely rare in the MLH1 methylated group. A subset of MLH1 methylated sporadic tumors demonstrated a unique, 'undifferentiated' histology that was not observed in HNPCC or the young group. CONCLUSION: Data suggest a genotype-phenotype relation in which microsatellite instability resulting from MLH1 methylation is almost exclusively associated with classical or 'undifferentiated' endometrioid tumors, whereas microsatellite instability secondary to MSH2 mutation can result in a more variable histologic spectrum of endometrial carcinoma.
Adaptor Proteins, Signal Transducing↗
BRCA1 and BRCA2 mutations in breast and ovarian cancer syndrome: reflection on the Creighton University historical series of high risk families.
Over the last four decades, Henry Lynch has collected pedigrees and samples from high risk breast and/or ovarian cancer families, generating a unique resource for the study of breast cancer susceptibility. These families have made a major contribution to increasing our knowledge in the cancer genetic susceptibility field, allowing the discovery of a genetic association between breast and ovarian cancer predisposition, contributing to the mapping of the BRCA1 and BRCA2 genes, advancing the idea of the existence of other breast cancer susceptibility genes, allowing the evaluation of BRCA-associated cancer risks and psychosocial aspects of BRCA testing and so on. Ten years after the cloning of BRCA1 and BRCA2, we report the current status of these families and compare the observed BRCA1/2 mutation detection rate with the estimations obtained by linkage analysis of the Breast Cancer Linkage Consortium families.
BRCA1 Protein↗
Patient responses to the disclosure of BRCA mutation tests in hereditary breast-ovarian cancer families.
Limited attention has been given to the impact of BRCA mutation disclosure on participants' psychological reaction and cancer control compliance. We asked women (290 mutation-positive, 370 mutation-negative) from 84 hereditary breast-ovarian cancer (HBOC) families with known deleterious BRCA mutations to participate in an evaluation regarding cancer prevention recommendations before and after BRCA mutation disclosure. Both men and women (n = 780) were invited to complete a questionnaire to evaluate their psychological response to BRCA mutation disclosure. Before BRCA testing, 23.0% (152 of 660) of these women underwent prophylactic bilateral mastectomy, oophorectomy, or both; of these, 53% (80 of 152) were subsequently found to be mutation negative. After mutation disclosure, 52.9% (110 of 208) of mutation carriers and 0% (0 of 203) of noncarriers underwent prophylactic surgeries. These changes were statistically significant compared with before disclosure (P < 0.0001). The rate of transvaginal ovarian ultrasound screening was significantly increased in mutation carriers (P < 0.015) and marginally decreased in noncarriers (P = 0.063) post disclosure. Psychologically, compared with noncarriers without cancer, a significantly higher percentage of carriers, regardless of their cancer status, felt guilt about passing a mutation to their children, worried about developing additional cancer or their children developing cancer, and were concerned about health insurance discrimination. Despite these psychological consequences, carriers and noncarriers reported a positive attitude toward genetic testing.
Breast Neoplasms↗
The I1307K APC polymorphism in Ashkenazi Jews with colorectal cancer: clinical and pathologic features.
Colorectal cancer is common in Ashkenazi Jews. The I1307K APC mutation occurs in 6-7% of Ashkenazi Jews and increases the risk of colorectal cancer. This study aimed to describe the clinical, pathologic and epidemiologic features of colorectal cancer in I1307K carriers to determine whether there were any features which might warrant individual screening for the mutation. In all, 215 Ashkenazi Jews with a personal history of colorectal cancer were enrolled. Clinical and family history, pathology reports, and slides were obtained and blood drawn for I1307K determination. The presence of the mutation was determined by PCR from white blood cell DNA. Colorectal cancer pathology slides were read in a blinded fashion. Of the 215 enrolled patients, 26 (12.1%) tested positive for I1307K. There was no difference in the pathologic features between colorectal cancers in Ashkenazi carriers compared to noncarriers. There was no difference in the age at diagnosis or history of second or other primaries. Carriers had an increased likelihood of having a first-degree relative with colorectal cancer (50%) compared to noncarriers (28%, P < 0.04). We could find no distinguishing feature other than family history that characterizes I1307K positive colorectal cancers. We could find no group of Ashkenazi Jews with colorectal cancer for whom screening for I1307K would be clinically useful.
Adult↗
Genotype/phenotype of familial pancreatic cancer.
It is estimated that 5% to 10% of pancreatic cancer cases are attributable to hereditary factors. We believe that the number of cases that are genetic in etiology are even greater, however, based not on a classic autosomal dominant pattern of inheritance but rather when one takes into account low-penetrant inherited susceptibility factors. There is also a growing recognition that the development of pancreatic cancer in pancreatic cancer-prone families is dependent not only on genetic variables but on nongenetic factors. The aim of this article is to review the challenges in identifying pancreatic cancer-prone families and how environmental factors interact with genetic factors in these families.
Adenocarcinoma↗
Mortality after bilateral salpingo-oophorectomy in BRCA1 and BRCA2 mutation carriers: a prospective cohort study.
BACKGROUND: Bilateral prophylactic salpingo-oophorectomy (BPSO) is used widely used to reduce the risk of breast and ovarian cancer in women with BRCA1 and BRCA2 mutations. However, the reduction in mortality after this surgery is unclear. We aimed to assess whether BPSO improves overall mortality or cancer-specific mortality in BRCA1 and BRCA2 mutation carriers. METHODS: We identified a prospective cohort of 666 women with disease-associated germline mutations in BRCA1 or BRCA2 and no previous cancer diagnosis. In our primary analysis, we compared 155 women who had had BPSO and 271 women matched for age at BPSO who had not had BPSO. In our secondary analysis, we compared 188 women who had had BPSO with 478 women who had not. In both analyses, we compared overall mortality and cancer-specific mortality. All analyses were adjusted for centre, mutation (BRCA1 vs BRCA2), and birth year. FINDINGS: In the primary analysis, mean follow-up from BPSO to censoring was 3.1 years [SD 2.4] in the BPSO group and 2.1 years [2.0] in the non-BPSO group. The hazard ratio (HR) for overall mortality was 0.24 (95% CI 0.08-0.71), for breast-cancer-specific mortality was 0.10 (0.02-0.71), and for ovarian-cancer-specific mortality was 0.05 (0.01-0.46) for women who had BPSO compared with those who had not. In secondary analysis, BPSO was associated with reduced overall mortality (HR 0.28 [95% CI 0.10-0.74]), but not with breast-cancer-specific mortality (0.15 [0.02-1.18] or ovarian-cancer-specific mortality (0.23 [0.02-1.87]. When regarded as a time-dependent covariate, BPSO was not associated significantly with mortality. INTERPRETATION: If confirmed, the finding that BPSO improves overall survival and cancer-specific survival in women with BRCA mutations will complement our existing knowledge of cancer-risk reduction associated with BPSO. Together, these data could give information to women who are considering genetic testing.
Adult↗
Screening mammography and risk of breast cancer in BRCA1 and BRCA2 mutation carriers: a case-control study.
BACKGROUND: Screening mammography is associated with a small dose of radiation to the breast, and women with increased genetic risk might be particularly sensitive to the DNA-damaging effects of ionising radiation. We aimed to assess whether exposure to ionising radiation through mammography screening was associated with risk of breast cancer in BRCA1 or BRCA2 mutation carriers. METHODS: We identified 1600 cases of breast cancer and 1600 controls without breast cancer who were matched for BRCA mutation, date of birth (within 1 year), and country of residence from an international registry of BRCA1 and BRCA2 mutation carriers. We used a questionnaire to inquire about whether participants had ever had screening mammography, and, if so, the age at which they first had the procedure. RESULTS: We found no association between ever having screening mammography and risk of breast cancer (odds ratio [OR] 1.03 [95% CI 0.85-1.25], adjusted for parity, oral-contraceptive use, ethnic origin, and bilateral oophorectomy). The association was much the same for BRCA1 mutation carriers and BRCA2 mutation carriers (1.04 [0.84-1.29] vs 1.06 [0.67-1.66], respectively, adjusted for parity, oral-contraceptive use, ethnic origin, and bilateral oophorectomy). INTERPRETATION: These findings do not lend support to the idea that exposure to ionising radiation through routine screening mammography contributes substantially to the burden of breast cancer in BRCA1 and BRCA2 mutation carriers. Prospective studies are needed to confirm the results of this initial report, and, where possible, these studies should assess a more appropriate endpoint of total exposure.
Adult↗
Phenotypic and genotypic heterogeneity in the Lynch syndrome: diagnostic, surveillance and management implications.
Lynch syndrome is the most common form of hereditary colorectal cancer (CRC). This review covers the cardinal features of Lynch syndrome with particular emphasis upon its diagnostic criteria, molecular genetics, natural history, genetic counseling, surveillance and management. Considerable attention has been given to the etiologic role of mismatch repair (MMR) genes as well as low penetrance alleles and modifier genes. The American founder mutation, a deletion of exons 1-6 of MSH2, is discussed in some detail, owing to its high frequency in the US (19 000-30 000 carriers). Genetic counseling is essential prior to patients' undergoing DNA testing and again when receiving their test results. Families with a lower incidence of CRC and extracolonic cancers, in the face of being positive for Amsterdam I criteria but who do not have MMR deficiency by tumor testing, are probably not Lynch syndrome, and thereby should preferably be designated as familial CRC of undetermined type. Patients who are either noncompliant or poorly compliant with colonoscopy, and who are MMR mutation positive, may be candidates for prophylactic colectomy, while MMR mutation-positive women who are noncompliant with gynecologic surveillance may be candidates for prophylactic hysterectomy and bilateral salpingo-oophorectomy.
Colorectal Neoplasms, Hereditary Nonpolyposis↗