Gene and pathway based burden analyses in familial lymphoid cancer cases: Rare variants in immune pathway genes

Genome-wide association studies have revealed common genetic variants with small effect sizes associated with diverse lymphoid cancers. Family studies have uncovered rare variants with high effect sizes. However, these variants explain only a portion of the heritability of these cancers. Some of the missing heritability may be attributable to rare variants with small effect sizes. We aim to identify rare germline variants associated with familial lymphoid cancers using exome sequencing. One case per family was selected from 39 lymphoid cancer families based on early onset of disease or rarity of subtype. Control data was from Non-Finnish Europeans in gnomAD exomes (N = 56,885) or ExAC (N = 33,370). Gene and pathway-based burden tests for rare variants were performed using TRAPD. Five putatively pathogenic germline variants were found in four genes: INTU, PEX7, EHHADH, and ASXL1. Pathway-based association tests identified the innate and adaptive immune systems, peroxisomal pathway and olfactory receptor pathway as associated with lymphoid cancers in familial cases. Our results suggest that rare inherited defects in the genes involved in immune system and peroxisomal pathway may predispose individuals to lymphoid cancers.

Variation in cancer risk among families with genetic susceptibility

Germline mutations in many genes have been shown to increase the risk of developing cancer. This risk can vary across families who carry mutations in the same gene due to differences in the specific variants, gene-gene interactions, other susceptibility mutations, environmental factors, and behavioral factors. We develop an analytic tool to explore this heterogeneity using family history data. We propose to evaluate the ratio between the number of observed cancer cases in a family and the number of expected cases under a model where risk is assumed to be the same across families. We perform this analysis for both carriers and noncarriers in each family, using carrier probabilities when carrier statuses are unknown, and visualize the results. We first illustrate the approach in simulated data and then apply it to data on colorectal cancer risk in families carrying mutations in Lynch syndrome genes from Creighton University's Hereditary Cancer Center. We show that colorectal cancer risk in carriers can vary widely across families, and that this variation is not matched by a corresponding variation in the noncarriers from the same families. This suggests that the sources of variation in these families are to be found predominantly in variants harbored in the mutated MMR genes considered, or in variants interacting with them.

Preferences for breast cancer prevention among women with a BRCA1 or BRCA2 mutation

Background

Women with a BRCA1 or BRCA2 mutation have high lifetime risks of developing breast and ovarian cancer. The decision to embark on risk reduction strategies is a difficult and personal one. We surveyed an international group of women with BRCA mutations and measured choices and sequence of breast cancer risk reduction strategies.

Methods

Women with a BRCA1/2 mutation and no previous cancer diagnosis were recruited from the US, Canada, the UK, Australia, and from a national advocacy group. Using an online survey, we asked about cancer-risk reduction preferences including for one of two hypothetical medicines, randomly assigned, and women’s recommendations for a hypothetical woman (Susan, either a 25- or 36-year-old). Sunburst diagrams were generated to illustrate hierarchy of choices.

Results

Among 598 respondents, mean age was 40.9 years (range 25–55 years). Timing of the survey was 4.8 years (mean) after learning their positive test result and 33% had risk-reducing bilateral salpingo-oophorectomy (RRBSO) and bilateral mastectomy (RRBM), while 19% had RRBSO only and 16% had RRBM only. Although 30% said they would take a hypothetical medicine, 6% reported taking a medicine resembling tamoxifen. Respondents were 1.5 times more likely to select a hypothetical medicine for risk reduction when Susan was 25 than when Susan was 36. Women assigned to 36-year-old Susan were more likely to choose a medicine if they had a family member diagnosed with breast cancer and personal experience taking tamoxifen.

Conclusions

Women revealed a willingness to undergo surgeries to achieve largest reduction in breast cancer risk, although this would not be recommended for a younger woman in her 20s. The goal of achieving the highest degree of cancer risk reduction is the primary driver for women with BRCA1 or BRCA2 mutations in selecting an intervention and a sequence of interventions, regardless of whether it is non-surgical or surgical.

Abstract 2300: Deleterious germline mutations in the BRCA1 gene are associated with increased risk for cancers of the female reproductive system other than breast and ovarian as well as other cancers

Introduction: Mutations within the BRCA1 gene have been linked to up to an 80% lifetime risk of breast cancer as well as increased risk for ovarian, pancreatic and melanoma cancers. In this study we examined families with known germline mutations in BRCA1 after long-term follow-up to determine whether carriers experience higher rates of other cancers that have not yet been associated with germline mutations in the BRCA1 gene.

Methods: We studied 127 Hereditary Breast and Ovarian Cancer (HBOC) syndrome families (N = 23,078 individuals who have been followed at Creighton University) in which a causal mutation in the BRCA1 gene was identified. We performed survival analysis and a mixed effects cox regression with age at follow-up or cancer event as our time variable and presence or absence of BRCA1-related or other cancers (separate analyses) as our indicator variable.

Results: The survival curves showed a significant age effect with carriers having a younger age at cancer onset for BRCA1-related (as expected) as well as other cancers than that of non-carriers. The cox regression models were also highly significant (P = 1.77E-37 and P = 1.04E-07 for the BRCA1-related and other cancers, respectively). Of the cancers with enough samples to do stratified analyses, uterine, skin, lymphoma and colon cancers occurred at higher rates and at earlier ages in mutation carriers.

Conclusions: These analyses support the hypothesis that the BRCA1 mutations carriers of HBOC syndrome have increased risk for early onset of several additional cancer types, especially cancers that arise in estrogen-influenced tissues.

Citation Format: Candace Middlebrooks, Kenzhane Pantin, Mark Stacey, Carrie Snyder, Murray J. Casey, Trudy Shaw, Joan E. Bailey-Wilson, Henry T. Lynch. Deleterious germline mutations in the BRCA1 gene are associated with increased risk for cancers of the female reproductive system other than breast and ovarian as well as other cancers [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2300.

Hormone Replacement Therapy After Oophorectomy and Breast Cancer Risk Among BRCA1 Mutation Carriers

Importance

Prophylactic bilateral salpingo-oophorectomy is recommended for BRCA1 mutation carriers to prevent ovarian cancer. Whether or not hormone replacement therapy (HRT) initiated after oophorectomy is associated with an increased risk of breast cancer has not been evaluated in a prospective study.

Objective

To determine the association between HRT use and BRCA1-associated breast cancer.

Design, Setting, and Participants

A prospective, longitudinal cohort study of BRCA1 and BRCA2 mutation carriers from 80 participating centers in 17 countries was conducted between 1995 and 2017 with a mean follow-up of 7.6 years. Participants had sought genetic testing for a BRCA1 or BRCA2 mutation because of a personal or family history of breast and/or ovarian cancer. Carriers of BRCA1 mutation with no personal medical history of cancer who underwent bilateral oophorectomy following enrollment were eligible for the cohort study.

Exposures

A follow-up questionnaire was administered every 2 years to obtain detailed information on HRT use. A left-truncated Cox proportional hazard analysis was used to estimate the hazard ratios (HRs) and 95% CIs associated with the initiation of HRT use postoophorectomy.

Main Outcomes and Measures

Incident breast cancer.

Results

A total of 872 BRCA1 mutation carriers with a mean postoophorectomy follow-up period of 7.6 years (range, 0.4-22.1) were included in this study. Mean (SD) age of participants was 43.4 (8.5) years. Among these, 92 (10.6%) incident breast cancers were diagnosed. Overall, HRT use after oophorectomy was not associated with an increased risk of breast cancer. The HR was 0.97 (95% CI, 0.62-1.52; P = .89) for ever use of any type of HRT vs no use; however, the effects of estrogen alone and combination hormonal therapy were different. After 10 years of follow-up, the cumulative incidence of breast cancer among women who used estrogen-alone HRT was 12% compared with 22% among women who used estrogen plus progesterone HRT (absolute difference, 10%; log rank P = .04).

Conclusions and Relevance

These findings suggest that use of estrogen after oophorectomy does not increase the risk of breast cancer among women with a BRCA1 mutation and should reassure BRCA1 mutation carriers considering preventive surgery that HRT is safe. The possible adverse effect of progesterone-containing HRT warrants further study.

Methylated SEPTIN9 plasma test for colorectal cancer detection may be applicable to Lynch syndrome

OBJECTIVE

The plasma-based methylated SEPTIN9 (mSEPT9) is a colorectal cancer (CRC) screening test for adults aged 50-75 years who are at average risk for CRC and have refused colonoscopy or faecal-based screening tests. The applicability of mSEPT9 for high-risk persons with Lynch syndrome (LS), the most common hereditary CRC condition, has not been assessed. This study sought preliminary evidence for the utility of mSEPT9 for CRC detection in LS.

DESIGN

Firstly, SEPT9 methylation was measured in LS-associated CRC, advanced adenoma, and subject-matched normal colorectal mucosa tissues by pyrosequencing. Secondly, to detect mSEPT9 as circulating tumor DNA, the plasma-based mSEPT9 test was retrospectively evaluated in LS subjects using the Epi proColon 2.0 CE assay adapted for 1mL plasma using the "1/1 algorithm". LS case groups included 20 peri-surgical cases with acolonoscopy-based diagnosis of CRC (stages I-IV), 13 post-surgical metastatic CRC, and 17 pre-diagnosis cases. The control group comprised 31 cancer-free LS subjects.

RESULTS

Differential hypermethylation was found in 97.3% (36/37) of primary CRC and 90.0% (18/20) of advanced adenomas, showing LS-associated neoplasia frequently produce the mSEPT9 biomarker. Sensitivity of plasma mSEPT9 to detect CRC was 70.0% (95% CI, 48%-88%)in cases with a colonoscopy-based CRC diagnosis and 92.3% (95% CI, 64%-100%) inpost-surgical metastatic cases. In pre-diagnosis cases, plasma mSEPT9 was detected within two months prior to colonoscopy-based CRC diagnosis in 3/5 cases. Specificity in controls was 100% (95% CI 89%-100%).

CONCLUSION

These preliminary findings suggest mSEPT9 may demonstrate similar diagnostic performance characteristics in LS as in the average-risk population, warranting a well-powered prospective case-control study.

International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation

BACKGROUND

Women with a BRCA1 or BRCA2 mutation face high risks of breast and ovarian cancer. In the current study, we report on uptake of cancer screening and risk-reduction options in a cohort of BRCA mutation carriers from ten countries over two time periods (1995 to 2008 and 2009 to 2017).

METHODS

Eligible subjects were identified from an international database of female BRCA mutation carriers and included women from 59 centres from ten countries. Subjects completed a questionnaire at the time of genetic testing, which included past use of cancer prevention options and screening tests. Biennial follow-up questionnaires were administered.

RESULTS

Six-thousand two-hundred and twenty-three women were followed for a mean of 7.5 years. The mean age at last follow-up was 52.1 years (27-96 years) and 42.3% of the women had a prior diagnosis of breast cancer. In all, 27.8% had a prophylactic bilateral mastectomy and  64.7% had a BSO. Screening with breast MRI increased from 70% before 2009 to 81% at or after 2009. There were significant differences in uptake of all options by country.

CONCLUSION

For women who received genetic testing more recently, uptake of prophylactic mastectomy and breast MRI is significantly higher than those who received genetic testing more than 10 years ago. However, uptake of both BSO and breast MRI is not optimal, and interventions to increase uptake are needed.

Analysis of the CDKN2A Gene in FAMMM Syndrome Families Reveals Early Age of Onset for Additional Syndromic Cancers

Familial atypical multiple mole melanoma (FAMMM) syndrome is a hereditary cancer syndrome that results from mutations in several genes, including the CDKN2A gene. In addition to melanoma, certain other malignancies such as pancreatic cancer are known to occur more frequently in family members who carry the mutation. However, as these families have been followed over time, additional cancers have been observed in both carriers and noncarriers. We sought to determine whether these additional cancers occur at higher frequencies in carriers than noncarriers. We performed survival analyses using 10 FAMMM syndrome families (N = 1,085 individuals) as well as a mixed effects Cox regression, with age at last visit to the clinic or age at cancer diagnosis as our time variable. This analysis was done separately for the known FAMMM-related cancers and "other" cancer groups. The survival curves showed a significant age effect with carriers having a younger age at cancer onset than noncarriers for FAMMM-related cancers (as expected) as well as for newly associated cancers. The Cox regression reflected what was seen in the survival curves, with all models being highly significant (P = 7.15E-20 and P = 5.00E-13 for the FAMMM-related and other cancers, respectively). These analyses support the hypothesis that CDKN2A mutation carriers in FAMMM syndrome families have increased risk for early onset of several cancer types beyond the known cancers. Therefore, these individuals should be screened for additional cancers, and mutation screening should be extended to more than first-degree relatives of an index carrier patient. SIGNIFICANCE: This study shows that carriers of mutations in the CDKN2A gene in FAMMM syndrome are at increased risk for early onset of several cancer types beyond the known cancers.

The association between smoking and cancer incidence in BRCA1 and BRCA2 mutation carriers

Tobacco smoke is an established carcinogen, but the association between tobacco smoking and cancer risk in BRCA mutation carriers is not clear. The aim of this study was to evaluate prospectively the association between tobacco smoking and cancer incidence in a cohort of BRCA1 and BRCA2 mutation carriers. The study population consisted of unaffected BRCA mutation carriers. Information on lifestyle including smoking histories, reproductive factors, and past medical histories was obtained through questionnaires. Incident cancers were updated biennially via follow-up questionnaires. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using time-dependent Cox regression models. There were 700 incident cancers diagnosed over 26,711 person-years of follow-up. The most frequent cancers seen in BRCA mutation carriers were breast (n = 428; 61%) and ovarian (n = 109; 15%) cancer. Compared to nonsmokers, (ever) smoking was associated with a modest increased risk of all cancers combined (HR = 1.17; 95%CI 1.01-1.37). Women in the highest group of total pack-years (4.3-9.8) had an increased risk of developing any cancer (HR = 1.27; 95%CI 1.04-1.56), breast cancer (HR = 1.33, 95%CI 1.02-1.75), and ovarian cancer (HR = 1.68; 95%CI 1.06-2.67) compared to never smokers. The associations between tobacco smoking and cancer did not differ by BRCA mutation type or by age at diagnosis. This prospective study suggests that tobacco smoking is associated with a modest increase in the risks of breast and ovarian cancer among women with BRCA1 or BRCA2 mutation.

Age-specific ovarian cancer risks among women with a BRCA1 or BRCA2 mutation

OBJECTIVES

For women at high risk of developing ovarian cancer, it is important to provide an accurate recommendation for the optimal age for preventive surgery in order to maximize the preventative effect while delaying symptoms associated with early surgical menopause. The goal of the current study was to estimate age-specific incidence rates of ovarian cancer among women with a BRCA1 or BRCA2 mutation.

METHODS

From our international registry, we identified 5689 women with no previous diagnosis of ovarian or fallopian tube cancer or preventive oophorectomy. Women were followed from the date of completion of the baseline questionnaire until either a diagnosis of ovarian or fallopian tube cancer, prophylactic oophorectomy, death or last follow-up. The annual and cumulative incidence rates of ovarian cancer were estimated.

RESULTS

Over a mean follow-up period of 4.7 years (ranges 0-22.6), 195 incident ovarian or fallopian tube cancers were diagnosed (169 [86%] ovarian cancers, 22 [11%] fallopian tube cancers and four [2%] cancers that involved both the ovaries and fallopian tubes). Of these, 45 (23%) cancers were diagnosed at preventive surgery (occult cancers). The cumulative risk of ovarian cancer to age 80 was 49% for BRCA1 and 21% for BRCA2 mutation carriers. The mean age at diagnosis was 51.3 years (ranges 33-84) among women with a BRCA1 mutation and 61.4 years (ranges 44-80) among women with a BRCA2 mutation.

CONCLUSION

Based on a cumulative risk of 0.55% to age 35 for BRCA1 mutation carriers and of 0.56% to age 45 for BRCA2 mutation carriers, we recommend bilateral salpingo-oophorectomy before age 40, but ideally by age 35, for women with a BRCA1 mutation and by age 45 for those with a BRCA2 mutation to maximize prevention and to minimize adverse effects.

The risk of breast cancer in BRCA1 and BRCA2 mutation carriers without a first-degree relative with breast cancer

The objective of this study was to estimate the lifetime risk of breast cancer in women with a BRCA1 or BRCA2 mutation with and without at least 1 first-degree relative with breast cancer. A total of 2835 women with a BRCA1 or BRCA2 mutation were followed. Age- and gene-specific breast cancer rates were calculated. The relative risks of breast cancer for subjects with a family history of breast cancer, compared to no family history were calculated. The mean age at baseline was 41.1 years, and they were followed for a mean of 6.0 years. The estimated penetrance of breast cancer to age 80 years was 60.8% for BRCA1 and 63.1% for BRCA2. For all BRCA carriers, the penetrance of breast cancer to age 80 for those with no first-degree relative with breast cancer was 60.4% and 63.3% for those with at least 1 first-degree relative with breast cancer. The risk of breast cancer for BRCA carriers with no first-degree relative with breast cancer is substantial, and as a result, clinical management for these women should be the same as those for women with an affected relative.

Germline Lysine-Specific Demethylase 1 (LSD1/KDM1A) Mutations Confer Susceptibility to Multiple Myeloma

Given the frequent and largely incurable occurrence of multiple myeloma, identification of germline genetic mutations that predispose cells to multiple myeloma may provide insight into disease etiology and the developmental mechanisms of its cell of origin, the plasma cell (PC). Here, we identified familial and early-onset multiple myeloma kindreds with truncating mutations in lysine-specific demethylase 1 (LSD1/KDM1A), an epigenetic transcriptional repressor that primarily demethylates histone H3 on lysine 4 and regulates hematopoietic stem cell self-renewal. In addition, we found higher rates of germline truncating and predicted deleterious missense KDM1A mutations in patients with multiple myeloma unselected for family history compared with controls. Both monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma cells have significantly lower KDM1A transcript levels compared with normal PCs. Transcriptome analysis of multiple myeloma cells from KDM1A mutation carriers shows enrichment of pathways and MYC target genes previously associated with myeloma pathogenesis. In mice, antigen challenge followed by pharmacologic inhibition of KDM1A promoted PC expansion, enhanced secondary immune response, elicited appearance of serum paraprotein, and mediated upregulation of MYC transcriptional targets. These changes are consistent with the development of MGUS. Collectively, our findings show that KDM1A is the first autosomal-dominant multiple myeloma germline predisposition gene providing new insights into its mechanistic roles as a tumor suppressor during post-germinal center B-cell differentiation.Significance: KDM1A is the first germline autosomal dominant predisposition gene identified in multiple myeloma and provides new insights into multiple myeloma etiology and the mechanistic role of KDM1A as a tumor suppressor during post-germinal center B-cell differentiation. Cancer Res; 78(10); 2747-59. ©2018 AACR.

Prospective evaluation of body size and breast cancer risk among BRCA1 and BRCA2 mutation carriers

BACKGROUND

Although evidence suggests that larger body size in early life confers lifelong protection from developing breast cancer, few studies have investigated the relationship between body size and breast cancer risk among BRCA mutation carriers. Therefore, we conducted a prospective evaluation of body size and the risk of breast cancer among BRCA mutation carriers.

METHODS

Current height and body mass index (BMI) at age 18 were determined from baseline questionnaires. Current BMI and weight change since age 18 were calculated from updated biennial follow-up questionnaires. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI).

RESULTS

Among 3734 BRCA mutation carriers, there were 338 incident breast cancers over a mean follow-up of 5.5 years. There was no association between height, current BMI or weight change and breast cancer risk. Women with BMI at age 18 ≥22.1 kg/m2 had a decreased risk of developing post-menopausal breast cancer compared with women with a BMI at age 18 between 18.8 and 20.3 kg/m2 (HR 0.49; 95% CI 0.30-0.82; P = 0.006). BMI at age 18 was not associated with risk of pre-menopausal breast cancer.

CONCLUSIONS

There was no observed association between height, current BMI and weight change and risk of breast cancer. The inverse relationship between greater BMI at age 18 and post-menopausal breast cancer further supports a role of early rather than current or adulthood exposures for BRCA-associated breast cancer development. Future studies with longer follow-up and additional measures of adiposity are necessary to confirm these findings.

Efficacy of proximal colectomy for surgical management of right-sided first colorectal cancer in Lynch Syndrome mutation carriers

BACKGROUND

This study analyzes the occurrence of colorectal cancer (CRC) in Lynch syndrome (LS) mutation carriers, interval until diagnosis of metachronous CRC, and survival after proximal colectomy (PC) compared with total (TC) and subtotal colectomy (STC) for right-sided first CRC in LS mutation carriers.

METHODS

Sixty-four LS mutation carriers with right-sided first CRC treated with PC or TC + STC were confirmed by clinical records. Bivariate analyses were examined for significance and life tables were generated for risk of metachronous CRC and survival estimates following surgery.

RESULTS

One of 16 (6.3%) mutation carriers treated with TC + STC developed subsequent CRC compared with 13/48 (27%) treated by PC. There was no significant difference in survival estimates between PC compared with TC + STC through 25 years after surgery.

CONCLUSION

Risk of subsequent CRC and survival estimates following PC and TC + STC should be considered in surgical management of right-sided first CRC in LS mutation carriers.

Familial atypical multiple mole melanoma (FAMMM) syndrome: history, genetics, and heterogeneity

Approximately 5-10 % of cutaneous melanoma occurs in kindreds with a hereditary predisposition. Mutations in the CDKN2A gene are found to occur in approximately 20-40 % of these kindreds. The first historical mention of what is now called the familial atypical multiple mole melanoma syndrome appears to be from 1820, with more reports throughout the 1950s, 1960s, and later years. In 1991, Lynch and Fusaro described an association between familial multiple mole melanoma and pancreatic cancer and work continues to elucidate the syndrome's genotypic and phenotypic heterogeneity. Individuals at risk for familial melanoma need periodic screenings. Unfortunately, adequate screening for pancreatic cancer does not currently exist, but pancreatic cancer's prominence in the hereditary setting will hopefully act as a stimulus for development of novel screening measures.

Curcumin: An age-old anti-inflammatory and anti-neoplastic agent

Curcumin is a natural anti-inflammatory agent that has been used for treating medical conditions for many years. Several experimental and pharmacologic trials have demonstrated its efficacy in the role as an anti-inflammatory agent. Curcumin has been shown to be effective in treating chronic conditions like rheumatoid arthritis, inflammatory bowel disease, Alzheimer's and common malignancies like colon, stomach, lung, breast, and skin cancers. As treatments in medicine become more and more complex, the answer may be something simpler. This is a review article written with the objective to systematically analyze the wealth of information regarding the medical use of curcumin, the "curry spice", and to understand the existent gaps which have prevented its widespread application in the medical community.

Preferences for breast cancer risk reduction among BRCA1/BRCA2 mutation carriers: a discrete-choice experiment

Purpose

Unaffected women who carry BRCA1 or BRCA2 mutations face difficult choices about reducing their breast cancer risk. Understanding their treatment preferences could help us improve patient counseling and inform drug trials. The objective was to explore preferences for various risk-reducing options among women with germline BRCA1/2 mutations using a discrete-choice experiment survey and to compare expressed preferences with actual behaviors.

Methods

A discrete-choice experiment survey was designed wherein women choose between hypothetical treatments to reduce breast cancer risk. The hypothetical treatments were characterized by the extent of breast cancer risk reduction, treatment duration, impact on fertility, hormone levels, risk of uterine cancer, and ease and mode of administration. Data were analyzed using a random-parameters logit model. Women were also asked to express their preference between surgical and chemoprevention options and to report on their actual risk-reduction actions. Women aged 25–55 years with germline BRCA1/2 mutations who were unaffected with breast or ovarian cancer were recruited through research registries at five clinics and a patient advocacy group.

Results

Between January 2015 and March 2016, 622 women completed the survey. Breast cancer risk reduction was the most important consideration expressed, followed by maintaining fertility. Among the subset of women who wished to have children in future, the ability to maintain fertility was the most important factor, followed by the extent of risk reduction. Many more women said they would take a chemoprevention drug than had actually taken chemoprevention.

Conclusions

Women with BRCA1/2 mutations indicated strong preferences for breast cancer risk reduction and maintaining fertility. The expressed desire to have a safe chemoprevention drug available to them was not met by current chemoprevention options.

Electronic supplementary material

The online version of this article (doi:10.1007/s10549-017-4332-3) contains supplementary material, which is available to authorized users.

Major hereditary gastrointestinal cancer syndromes: a narrative review

Gastrointestinal cancer is one of the major causes of death worldwide. Hereditary gastrointestinal cancer syndromes constitute about 5-10% of all cancers. About 20-25% of undiagnosed cases have a possible hereditary component, which is not yet established. In the last few decades, the advance in genomics has led to the discovery of multiple cancer predisposition genes in gastrointestinal cancer. Physicians should be aware of these syndromes to identify high-risk patients and offer genetic testing to prevent cancer death. In this review, we describe clinical manifestations, genetic testing and its challenges, diagnosis and management of the major hereditary gastrointestinal cancer syndromes.

Abstract P3-08-08: Preferences for breast cancer risk reduction among BRCA1 and BRCA2 mutation carriers: A discrete choice experiment

This abstract was withdrawn by the authors.

Bilateral Oophorectomy and Breast Cancer Risk in BRCA1 and BRCA2 Mutation Carriers

Background

Whether oophorectomy reduces breast cancer risk among BRCA mutation carriers is a matter of debate. We undertook a prospective analysis of bilateral oophorectomy and breast cancer risk in BRCA mutation carriers.

Methods

Subjects had no history of cancer, had both breasts intact, and had information on oophorectomy status (n = 3722). Women were followed until breast cancer diagnosis, prophylactic bilateral mastectomy, or death. A Cox regression model was used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of breast cancer associated with oophorectomy (coded as a time-dependent variable). All statistical tests were two-sided.

Results

Over a mean follow-up of 5.6 years, 350 new breast cancers were diagnosed. Among women with a BRCA1 or BRCA2 mutation, oophorectomy was not associated with breast cancer risk compared with women who did not undergo an oophorectomy. The age-adjusted hazard ratio associated with oophorectomy was 0.96 (95% CI = 0.73 to 1.26, P = 76) for BRCA1 and was 0.65 (95% CI = 0.37 to 1.16, P = 14) for BRCA2 mutation carriers. In stratified analyses, the effect of oophorectomy was statistically significant for breast cancer in BRCA2 mutation carriers diagnosed prior to age 50 years (age-adjusted HR = 0.18, 95% CI = 0.05 to 0.63, P = 007). Oophorectomy was not associated with risk of breast cancer prior to age 50 years among BRCA1 mutation carriers (age-adjusted HR = 0.79, 95% CI = 0.55 to 1.13, P = 51).

Conclusions

Findings from this large prospective study support a role of oophorectomy for the prevention of premenopausal breast cancer in BRCA2, but not BRCA1 mutation carriers. These findings warrant further evaluation.

Commentary on Almassalha et al., "The Greater Genomic Landscape: The Heterogeneous Evolution of Cancer"

In this issue of Cancer Research, Almassalha and colleagues have proposed a new concept of the development of malignancy, that of the greater genomic landscape. They propose a stressor-related exploration of intracellular genomic sites as a response mechanism. This process can express sites with beneficial or deleterious effects, among them those that promote cell proliferation. They point out that their conception is broader, although certainly inclusive, of the process of gene induction. The authors view the physical process of chromatin reorganization as central to the exploration of the genomic landscape. Accordingly, they advocate the development of agents to limit chromatin structural modification as a chemotherapeutic approach in cancer. We found their theory relevant to understand the phenotypic heterogeneity of malignancy, particularly in familial cancer syndromes. For example, the familial atypical multiple mole melanoma (FAMMM) syndrome, related to a gene mutation, is characterized by a diversity of melanocytic lesions, only some of which become malignant melanoma. This new conceptualization can do much to increase understanding of the diversity of malignancy in families with hereditary cancer. Cancer Res; 76(19); 5602-4. ©2016 AACR.

Risk factors for endometrial cancer among women with a BRCA1 or BRCA2 mutation: a case control study

BRCA mutation carriers may use tamoxifen for breast cancer prevention or treatment. Hormone replacement therapy is often prescribed after surgical menopause and oral contraceptives are recommended for ovarian cancer prevention. The objective of this study was to assess the impact of these medications and other risk factors on endometrial cancer risk in BRCA carriers. Women with a BRCA1 or BRCA2 mutation were identified from a registry of mutation carriers. Cases were 83 women who had a diagnosis of endometrial cancer. Controls were 1027 matched women who did not develop endometrial cancer and who had an intact uterus. All women completed a baseline questionnaire, which included questions about ages at menarche and menopause, oral contraceptive use, hormone replacement therapy use, hysterectomy, oophorectomy, breast cancer history and tamoxifen use. We estimated the odds ratio associated with each risk factor in a multivariate analysis. No differences were found between cases and controls in terms of age at menarche, BMI, smoking, or oral contraceptive use. In a multivariate analysis, for women taking estrogen-only hormone replacement therapy, the odds ratio was 0.23 (95% CI 0.03-1.78, p = 0.16), and for women taking progesterone-only hormone replacement therapy the odds ratio was 6.91 (95% CI 0.99-98.1, p = 0.05). The adjusted odds ratio for endometrial cancer associated with a history of tamoxifen use was 3.50 (95% CI 1.51-8.10, p = 0.003). The observed increased risk of endometrial cancer associated with progesterone-only therapy merits further study.

Mutations in the Histone Modifier PRDM6 Are Associated with Isolated Nonsyndromic Patent Ductus Arteriosus

Nonsyndromic patent ductus arteriosus (PDA) is a common congenital heart defect (CHD) with both inherited and acquired causes, but the disease mechanisms have remained elusive. Using combined genome-wide linkage analysis and whole-exome sequencing (WES), we identified independent mutations in PRDM6, which encodes a nuclear protein that is specific to vascular smooth muscle cells (VSMC), has histone methyl transferase activities, and acts as a transcriptional suppressor of contractile proteins. In vitro assays showed that the mutations cause loss of function either by intracellular redistribution of the protein and/or by alteration of its methyltransferase activities. Wild-type embryonic ductus arteriosus (DA) exhibited high levels of PRDM6, which rapidly declined postnatally as the number of VSMCs necessary for ductus contraction increased. This dynamic change suggests that PRDM6 plays a key role in maintaining VSMCs in an undifferentiated stage in order to promote their proliferation and that its loss of activity results in premature differentiation and impaired remodeling of the DA. Our findings identify PRDM6 mutations as underlying genetic causes of nonsyndromic isolated PDA in humans and implicates the wild-type protein in epigenetic regulation of ductus remodeling.

Effect of Oophorectomy on Survival After Breast Cancer in BRCA1 and BRCA2 Mutation Carriers

IMPORTANCE

Women who carry a germline mutation in either the BRCA1 or BRCA2 gene face a lifetime risk of breast cancer of up to 70%, and once they receive a diagnosis of breast cancer, they face high risks of both second primary breast and ovarian cancers. Preventive bilateral salpingo-oophorectomy is recommended to women with a BRCA mutation at age 35 years or thereafter to prevent breast and ovarian cancer, but it is unclear whether oophorectomy has an impact on survival in women with BRCA-associated breast cancer.

OBJECTIVE

To estimate the impact of oophorectomy on survival in women with breast cancer with a BRCA1 or BRCA2 mutation.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective analysis of patients selected by pedigree review of families who received counseling at 1 of 12 participating clinical genetics centers. Patients were 676 women with stage I or II breast cancer and a BRCA1 or BRCA2 mutation who were observed for up to 20 years after receiving a diagnosis between 1975 and 2008. Survival experience was compared for women who did and who did not undergo oophorectomy.

MAIN OUTCOMES AND MEASURES

In all analyses, the primary end point was death due to breast cancer.

RESULTS

Of the 676 women, 345 underwent oophorectomy after the diagnosis of breast cancer and 331 retained both ovaries. The 20-year survival for the entire patient cohort was 77.4%. The adjusted hazard ratio for death attributed to breast cancer in women who underwent oophorectomy was 0.38 (95% CI, 0.19-0.77; P = .007) for BRCA1 carriers and 0.57 (95% CI, 0.23-1.43; P = .23) for BRCA2 carriers. The hazard ratio for breast cancer-specific mortality was 0.76 (95% CI, 0.32-1.78; P = .53) for women with estrogen receptor-positive breast cancer and 0.07 (95% CI, 0.01-0.51; P = .009) for women with estrogen receptor-negative breast cancer.

CONCLUSIONS AND RELEVANCE

Oophorectomy is associated with a decrease in mortality in women with breast cancer and a BRCA1 mutation. Women with estrogen receptor-negative breast cancer and a BRCA1 mutation should undergo oophorectomy shortly after diagnosis.

Lynch syndrome in the 21st century: clinical perspectives

Lynch syndrome (LS) is the most common of all inherited cancer syndromes, associated with substantially elevated risks for colonic and extracolonic malignancies, earlier onset and high rates of multiple primary cancers. At the genetic level, it is caused by a defective mismatch repair (MMR) system due to presence of germline defects in at least one of the MMR genes- MLH1, MSH2, MSH6, PMS2 or EPCAM. An impaired MMR function during replication introduces infidelity in DNA sequence and leads to ubiquitous mutations at simple repetitive sequences (microsatellites), causing microsatellite instability (MSI). Although previously, clinicopathological criteria such as Amsterdam I/II and Revised Bethesda Guidelines were commonly used to identify suspected LS mutation carriers, there has been a recent push towards universally testing, especially in case of colorectal cancers (CRCs), through immunohistochemistry for expression of MMR proteins or through molecular tests (polymerase chain reaction, PCR) for MSI, in order to identify LS mutation carriers and subject them to genetic testing to ascertain the specific gene implicated. In this review, we have discussed the latest diagnostic strategies and the current screening and treatment guidelines for colonic and extracolonic cancers in clinically affected and at-risk individuals for LS.

Mutation spectrum and risk of colorectal cancer in African American families with Lynch syndrome

BACKGROUND & AIMS

African Americans (AAs) have the highest incidence of and mortality resulting from colorectal cancer (CRC) in the United States. Few data are available on genetic and nongenetic risk factors for CRC among AAs. Little is known about cancer risks and mutations in mismatch repair (MMR) genes in AAs with the most common inherited CRC condition, Lynch syndrome. We aimed to characterize phenotype, mutation spectrum, and risk of CRC in AAs with Lynch syndrome.

METHODS

We performed a retrospective study of AAs with mutations in MMR genes (MLH1, MSH2, MSH6, and PMS2) using databases from 13 US referral centers. We analyzed data on personal and family histories of cancer. Modified segregation analysis conditioned on ascertainment criteria was used to estimate age- and sex-specific CRC cumulative risk, studying members of the mutation-carrying families.

RESULTS

We identified 51 AA families with deleterious mutations that disrupt function of the MMR gene product: 31 in MLH1 (61%), 11 in MSH2 (21%), 3 in MSH6 (6%), and 6 in PMS2 (12%); 8 mutations were detected in more than 1 individual, and 11 have not been previously reported. In the 920 members of the 51 families with deleterious mutations, the cumulative risks of CRC at 80 years of age were estimated to be 36.2% (95% confidence interval [CI], 10.5%-83.9%) for men and 29.7% (95% CI, 8.31%-76.1%) for women. CRC risk was significantly higher among individuals with mutations in MLH1 or MSH2 (hazard ratio, 13.9; 95% CI, 3.44-56.5).

CONCLUSIONS

We estimate the cumulative risk for CRC in AAs with MMR gene mutations to be similar to that of individuals of European descent with Lynch syndrome. Two-thirds of mutations were found in MLH1, some of which were found in multiple individuals and some that have not been previously reported. Differences in mutation spectrum are likely to reflect the genetic diversity of this population.

Weight gain after oophorectomy among women with a BRCA1 or BRCA2 mutation

AIM

To measure weight gain among unaffected women with a BRCA1 or BRCA2 mutation after undergoing an oophorectomy.

PATIENTS & METHODS

We compared the bodyweight of women with (n = 405) and without an oophorectomy (n = 741) at baseline as well as the rate of weight change prior to and following surgery among 1454 BRCA mutation carriers who had an oophorectomy.

RESULTS

There was a small and non-significant difference in bodyweight between BRCA mutation carriers who had an oophorectomy compared with those women who did not (151.5 vs 149.1 pounds; p = 0.26). There was an increase in bodyweight with increasing age, but this relationship did not differ prior to and following surgery (p comparing the slope parameters = 0.78).

CONCLUSION

Oophorectomy is not associated with significant weight gain in high-risk women.

Genetics, biomarkers, hereditary cancer syndrome diagnosis, heterogeneity and treatment: a review

OPINION STATEMENT

Molecular genetic pathways that drive the phenotypic and genotypic heterogeneity of hereditary colorectal cancer also can affect response to chemotherapy and chemoprevention. These mutations also can alter patients' response to therapy. Environmental differences can affect this highly complex conundrum. We will use Lynch syndrome as a model to explore this issue. However, to begin with, after more than a century of documentation, we must ask what is meant by the eponym "Lynch syndrome". Germline mutations may act as drivers of chemoprevention and chemotherapy and therein may act positively or conversely they may have a negative effect in terms of inhibiting the inactivation of cancer-causing germline mutations. A relatively new field of hereditary cancer therapeutics has significantly impacted cancer care, from the standpoint of the sensitivity or resistance to a particular form of chemotherapy and/or chemoprevention. The question for the diagnostician and therapist must always concern what is the best possible management approach for the patient, particularly when he or she harbors a cancer-causing germline mutation, which, in this case, causes Lynch syndrome. Continued molecular genetic research might yield a more tailored effective treatment for Lynch syndrome. The ultimate goal of such hereditary oncologic research is to better understand the mutation's therapeutic task, namely, its potential to benefit the patient in terms of its treatment goal, thereby fulfilling the essence of personalized medicine. However, this goal may be exceedingly complicated. For example, in the natural clinical and molecular genetic history of hereditary forms of cancer, there will be a predominance of early-onset cancers of multiple anatomic sites. In our Lynch syndrome model, these will be most commonly colorectal, endometrial, and ovarian cancer. Attention must initially be focused upon cancer's early age of onset coupled with the tendency to multiple primary cancers so that, in the case of CRC, colonoscopic screening must be initiated by age 20-25 years and repeated every other year until age 40 years and then annually thereafter. However, screening will be of limited efficacy in the gynecologic cancers (endometrial and ovarian) so that once the family is completed, particularly by age 35-40 years, careful attention must be given to the option of prophylactic hysterectomy and bilateral salpingo-oophorectomy. Given issues of tumor heterogeneity, selected Lynch syndrome families may show an excess of urologic cancers or cancers of the small bowel, and highly targeted screening should be given serious consideration for these as well as cancers of other anatomic sites in such high-risk, cancer-prone patients.

Prospective evaluation of alcohol consumption and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers

Given the adverse effect of alcohol in the development of breast cancer among women in the general population, we evaluated whether a similar association exists among women with a BRCA1 or BRCA2 mutation. Information regarding baseline daily alcohol consumption was abstracted from a research questionnaire for 3067 BRCA mutation carriers enrolled in a prospective cohort study. Women were followed biennially until the date of the last follow-up questionnaire, date of breast cancer diagnosis, date of prophylactic bilateral mastectomy, or date of death. Cox proportional hazards models were used to estimate relative risks (RRs) and 95 % confidence intervals (CIs) for invasive breast cancer associated with alcohol consumed at or prior to completion of the baseline questionnaire. After a mean of 5.4 years of follow-up, we observed 259 incident cases of primary invasive breast cancer. Compared with non-users, the adjusted RRs were 1.06 (95 % CI 0.78-1.44) for ever use and 1.08 (0.79-1.47) for current alcohol use. For women in the highest versus lowest quintile of cumulative alcohol consumption, the RR was 0.94 (95 % CI 0.63-1.40; P trend = 0.65). Our findings suggest that alcohol consumption is not a risk factor for breast cancer among women with a BRCA1 or BRCA2 mutation.

Practical genetics of colorectal cancer

Hereditary colorectal cancer (CRC) is highly heterogeneous, both genotypically and phenotypically. The most frequently occurring hereditary colorectal cancer syndrome is Lynch syndrome, accounting for approximately 3% of the total colorectal cancer burden. Polyposis syndromes, such as familial adenomatous polyposis, account for a lesser percentage. Familial colorectal cancer, defined by family history, occurs in an estimated 20% of all colorectal cancer cases. With a worldwide annual colorectal cancer incidence of over one million, and annual mortality of over 600,000, hereditary and familial forms of colorectal cancer are a major public health problem. Lynch syndrome is attributable to DNA mismatch repair germline mutations, with the MSH2, MLH1, MSH6, and PMS2 genes being implicated. The characteristics of Lynch syndrome-associated colorectal tumors, including early age of onset and predilection to the proximal colon, mandate surveillance by colonoscopy beginning by age 20 to 25 and repeated every other year through age 40 and annually thereafter. Besides colorectal cancer, Lynch syndrome also predisposes to a litany of extracolonic cancers, foremost of which is endometrial cancer, followed by cancer of the ovary, stomach, renal pelvis and ureter, small bowel, hepatobiliary tract, pancreas, glioblastoma multiforme in the Turcot's variant, and sebaceous skin tumors in the Muir-Torre variant and, more recently identified, cancers of the breast and prostate. The most common polyposis syndrome is familial adenomatous polyposis, caused by mutations in the APC gene. Affected individuals have multiple colonic adenomas and, without treatment invariably develop colorectal cancer. Colonic surveillance with polypectomy may be pursued until the appearance of multiple colonic adenomas, at which time prophylactic colectomy should be considered. Extra-intestinal manifestations include desmoid tumor, hepatoblastoma, thyroid carcinoma, and medulloblastoma. Other polyposis syndromes include the hamartomatous polyp syndromes, including juvenile polyposis syndrome, Peutz-Jeghers syndrome, Cowden syndrome, and Bannayan-Ruvalcaba-Riley syndrome.

Milestones of Lynch syndrome: 1895-2015

Lynch syndrome, which is now recognized as the most common hereditary colorectal cancer condition, is characterized by the predisposition to a spectrum of cancers, primarily colorectal cancer and endometrial cancer. We chronicle over a century of discoveries that revolutionized the diagnosis and clinical management of Lynch syndrome, beginning in 1895 with Warthin's observations of familial cancer clusters, through the clinical era led by Lynch and the genetic era heralded by the discovery of causative mutations in mismatch repair (MMR) genes, to ongoing challenges.