Impact of rapid genetic testing for BRCA1 and BRCA2 at time of breast cancer diagnosis on psychosocial functioning

PURPOSE

Many women are being offered rapid genetic testing (RGT) for cancer predisposition genes, at the time of breast cancer diagnosis prior to surgery. The goal of this study was to determine if psychosocial functioning was affected in women receiving RGT for BRCA1 and BRCA2 at the time of breast cancer diagnosis.

METHODS

Participants were women with invasive breast cancer diagnosed between 2013 and 2018, at four centres in Toronto, Canada. Eligible women were referred into the study by their surgeon at the time of diagnosis. Participants received pre-test genetic counselling and were offered RGT for BRCA1 and BRCA2. Standardized questionnaires (Impact of Event Scale and Hospital Anxiety and Depression Scale) were completed before genetic counselling, and follow-up questionnaires at one-week and one-year post-genetic test result disclosure (higher scores indicate higher symptoms).

RESULTS

1007 women had RGT; 60 women (6.0%) were found to have a BRCA1 or BRCA2 mutation, 80 women (7.9%) had a VUS, and 867 (86.1%) had a negative test result. At one-week post-testing, there were no differences in distress (p = 0.32), anxiety (p = 0.14), or depression (p = 0.42) between women with a BRCA1/2 mutation and those with a negative result. At one year, there were no differences in distress (p = 0.75) or anxiety (p = 0.13) between women with a BRCA1 or BRCA/2 mutation and those with a negative result. However, women with a BRCA1 or BRCA2 mutation had significantly lower depression scores compared to women with a negative result (p = 0.03).

CONCLUSION

For women who have RGT for BRCA1 and BRCA2 at the time of breast cancer diagnosis, identifying a BRCA1 or BRCA2 mutation does not impair psychosocial functioning in the short or long term.

Blood Copper Levels and the Occurrence of Colorectal Cancer in Poland

There is a need for sensitive and specific biomarkers for the early detection of colorectal cancer. In this retrospective study, we assessed whether a high blood copper level was associated with the presence of colorectal cancer. The blood copper level was measured among 187 colorectal cancer patients and 187 matched controls. Cases and controls were matched for sex, smoking status (yes/no) and year of birth. Among the cases, the mean blood copper level was 1031 µg/L (range 657 µg/L to 2043 µg/L) and among the controls, the mean blood copper level was 864 µg/L (range 589 µg/L to 1433 µg/L). The odds ratio for colorectal cancer for those in the highest quartile of copper level (versus the lowest) was 12.7 (95% CI: 4.98–32.3; p < 0.001). Of the patients with stage I–II colon cancer, 62% had a copper level in the highest quartile. A blood copper level in excess of 930 µg/L is associated with an increase in the prevalence of colorectal cancer in the Polish population and its potential use in early detection programs should be considered.

Association between chronic bladder catheterisation and bladder cancer incidence and mortality: a population-based retrospective cohort study in Ontario, Canada

OBJECTIVES

To compare the risk of bladder cancer and bladder cancer mortality among patients with chronic bladder catheterisation (indwelling or intermittent) to patients from the general population.

DESIGN

Retrospective cohort study.

SETTING

Population-based study in Ontario, Canada between 2003 and 2018.

PARTICIPANTS

Adult patients 18-90 years of age with chronic bladder catheterisation were hard matched to patients from the general population without a history of bladder catheterisation.

INTERVENTIONS

The presence of a chronic catheter was defined as a minimum of two physician encounters for bladder catheterisation, suprapubic tube insertion or home care for catheter care separated by at least 28 days. Urinary tract infection (UTI) rates were collected.

MAIN OUTCOME MEASURES

Bladder cancer and bladder cancer-specific mortality after a 1-year lag period were compared between groups.

RESULTS

We identified 36 903 patients with chronic catheterisation matched to 110 709 patients without a history of catheterisation. Patients were followed for a median of 8.8 years (IQR: 5.2-11.9 years). The median age was 62 years (IQR: 50-71) and 52% were female. More patients in the catheter group developed bladder cancer (393 (1.1%) vs 304 (0.3%),p<0.001). There were 106 (0.3%) bladder cancer deaths in the catheter group and 59 (0.1%) in the comparison group (p<0.001). Chronic catheterisation (adjusted subdistribution HR (sdHR)=4.80, 95% CI: 4.26 to 5.42,p<0.001) and the number of UTIs (adjusted sdHR=1.04 per UTI, 95% CI: 1.04 to 1.05,p<0.001) were independent predictors of bladder cancer. The relative rate of bladder cancer-specific death was more than eightfold higher among patients with chronic catheterisation (adjusted sdHR=8.68, 95% CI: 6.97 to 10.81,p<0.001). Subgroup analysis among patients with neurogenic bladder and bladder calculi similarly revealed an increased risk of bladder cancer diagnosis and mortality. Bladder cancer risk was highest among patients in the two longest catheter duration quintiles (2.9-5.9 and 5.9-15.5 years).

CONCLUSIONS

This is the first study to quantify the increase in bladder cancer incidence and mortality in a large, diverse cohort of patients with chronic indwelling or intermittent bladder catheterisation. The risk was highest among patients with a chronic catheter beyond 2.9 years.

Genetic predisposition to male breast cancer in Poland

BACKGROUND

Breast cancer in men accounts for fewer than 1 % of all breast cancer cases diagnosed in men and women. Genes which predispose to male breast cancer include BRCA1 and BRCA2. The role of other genes is less clear. In Poland, 20 founder mutations in BRCA1, BRCA2, CHEK2, PALB2, NBN, RECQL are responsible for the majority of hereditary breast cancer cases in women, but the utility this genes panel has not been tested in men.

METHODS

We estimated the prevalence of 20 alleles in six genes (BRCA1, BRCA2, CHEK2, PALB2, NBN, RECQL) in 165 Polish male breast cancer patients. We compared the frequency of selected variants in male breast cancer cases and controls.

RESULTS

One of the 20 mutations was seen in 22 of 165 cases (13.3%). Only one BRCA1 mutation and two BRCA2 mutations were found. We observed statistically significant associations for PALB2 and CHEK2 truncating mutations. A PALB2 mutation was detected in four cases (OR = 11.66; p < 0.001). A CHEK2 truncating mutation was detected in five cases (OR = 2.93;p = 0.02).

CONCLUSION

In conclusion, we recommend that a molecular test for BRCA1, BRCA2, PALB2 and CHEK2 recurrent mutations should be offered to male breast cancer patients in Poland.

Weight Gain and the Risk of Ovarian Cancer in BRCA1 and BRCA2 Mutation Carriers

BACKGROUND

Weight gain and other anthropometric measures on the risk of ovarian cancer for women with BRCA mutations are not known. We conducted a prospective analysis of weight change since age 18, height, body mass index (BMI) at age 18, and current BMI and the risk of developing ovarian cancer among BRCA1 and BRCA2 mutation carriers.

METHODS

In this prospective cohort study, height, weight, and weight at age 18 were collected at study enrollment. Weight was updated biennially. Cox proportional hazards models were used to estimate the hazard ratio (HR) and 95% confidence intervals (CI) for ovarian cancer.

RESULTS

This study followed 4,340 women prospectively. There were 121 incident cases of ovarian cancer. Weight gain of more than 20 kg since age 18 was associated with a 2-fold increased risk of ovarian cancer, compared with women who maintained a stable weight (HR, 2.00; 95% CI, 1.13-3.54; P = 0.02). Current BMI of 26.5 kg/m² or greater was associated with an increased risk of ovarian cancer in BRCA1 mutation carriers, compared with those with a BMI less than 20.8 kg/m² (Q4 vs. Q1 HR, 2.13; 95% CI, 1.04-4.36; P = 0.04). There were no significant associations between height or BMI at age 18 and risk of ovarian cancer.

CONCLUSIONS

Adult weight gain is a risk factor for ovarian cancer in women with a BRCA1 or BRCA2 mutation.

IMPACT

These findings emphasize the importance of maintaining a healthy body weight throughout adulthood in women at high risk for ovarian cancer.

Incidence of Cancer Among Adults With Thrombocytosis in Ontario, Canada

IMPORTANCE

Individuals with newly diagnosed cancer often have a high platelet count (thrombocytosis). Whether thrombocytosis is associated with the presence of an undiagnosed cancer remains unknown.

OBJECTIVE

To assess whether a new diagnosis of thrombocytosis is associated with a subsequent risk of cancer among adults.

DESIGN, SETTING, AND PARTICIPANTS

This population-based retrospective cohort study was conducted using linked laboratory data from Ontario, Canada, from January 1, 2007, to December 31, 2017, with follow-up until December 31, 2018. The study cohort included adults aged 40 to 75 years on the date of a routine complete blood count (CBC) test (index test) who had a normal platelet count in the 2 previous years and no history of cancer. Data analysis was performed in December 2020.

EXPOSURES

Exposed individuals were those with a platelet count greater than 450 × 109/L. Matched unexposed control individuals had a platelet count within the reference range (150 × 109/L to 450 × 109/L) reported within 30 days of the exposure.

MAIN OUTCOMES AND MEASURES

Incident cancers within 5 years after diagnosis of thrombocytosis. Absolute and relative risks for cancer associated with thrombocytosis were estimated for all cancers and for cancers at specific sites.

RESULTS

Of the 3 386 716 Ontario residents with a recorded routine CBC test result, 53 339 (1.6%) had thrombocytosis and a prior normal platelet count. Among individuals with thrombocytosis, the median age was 59.7 years (interquartile range, 50.2-67.4 years) and 37 349 (70.0%) were women. Among the 51 624 individuals with thrombocytosis included in the matched analysis, 2844 (5.5%) had received a diagnosis of a solid cancer in the 2-year follow-up period and 3869 (7.5%) had received a diagnosis within 5 years. The relative risk (RR) for developing any solid cancer within 2 years was 2.67 (95% CI, 2.56-2.79). Associations were found between thrombocytosis and cancers of the ovary (RR, 7.11; 95% CI, 5.59-9.03), stomach (RR, 5.53; 95% CI, 4.12-7.41), colon (RR, 5.41; 95% CI, 4.80-6.10), lung (RR, 4.41; 95% CI, 4.02-4.85), kidney (RR, 3.64; 95% CI, 2.94-4.51), and esophagus (RR, 3.64; 95% CI, 2.46-5.40).

CONCLUSIONS AND RELEVANCE

In this cohort study, an increased platelet count was associated with an increased risk of cancer for at least 2 years. The results suggest that individuals with unexplained thrombocytosis should be offered screening for several cancers.

The risk of contralateral breast cancer: a SEER-based analysis

BACKGROUND

We sought to estimate the annual risk and 25-year cumulative risk of contralateral breast cancer among women with stage 0-III unilateral breast cancer.

METHODS

We identified 812,851 women with unilateral breast cancer diagnosed between 1990 and 2015 in the SEER database and followed them for contralateral breast cancer for up to 25 years. Women with a known bilateral mastectomy were excluded. We calculated the annual risk of contralateral breast cancer by age at diagnosis, by time since diagnosis and by current age. We compared risks by ductal carcinoma in situ (DCIS) versus invasive disease, by race and by oestrogen receptor (ER) status of the first cancer.

RESULTS

There were 25,958 cases of contralateral invasive breast cancer diagnosed (3.2% of all patients). The annual risk of contralateral breast cancer over the 25-year follow-up period was 0.37% and the 25-year actuarial risk of contralateral invasive breast cancer was 9.9%. The annual risk varied to a small degree by age of diagnosis, by time elapsed since diagnosis and by current age. The 25-year actuarial risk was similar for DCIS and invasive breast cancer patients (10.1 versus 9.9%). The 25-year actuarial risk was higher for black women (12.7%) than for white women (9.7%) and was lower for women with ER-positive breast cancer (9.5%) than for women with ER-negative breast cancer (11.2%).

CONCLUSIONS

Women with unilateral breast cancer experience an annual risk of contralateral breast cancer ~0.4% per year, which persists over the 25-year follow-up period.

Survival Differences in Chinese Versus White Women With Breast Cancer in the United States: A SEER-Based Analysis

PURPOSE

The affect of race on breast cancer prognosis is not well understood. We compared crude and adjusted breast cancer survival rates of Chinese women versus White women in the United States.

METHODS

We conducted a cohort study of Chinese and White women with breast cancer diagnosed between 2004 to 2015 in the SEER 18 registries database. We abstracted information on age at diagnosis, tumor size, grade, lymph node status, receptor status, surgical treatment, receipt of radiotherapy and chemotherapy, and death. We compared crude breast cancer–specific mortality between the two ethnic groups. We calculated adjusted hazard ratios (HRs) in a propensity-matched design using the Cox proportional hazards model. P < .05 was considered statistically significant.

RESULTS

There were 7,553 Chinese women (1.8%) and 414,618 White women (98.2%) with stage I-IV breast cancer in the SEER database. There were small differences in demographics, nodal burden, and clinical stage between Chinese and White women. Ten-year breast cancer–specific survival was 88.8% for Chinese women and 85.6% for White women (HR, 0.73; 95% CI, 0.67 to 0.80; P < .0001). In a propensity-matched analysis among women with stage I–IIIC breast cancer, the HR was 0.71 (95% CI, 0.62 to 0.81; P < .0001). Annual mortality rates in White women exceeded those in Chinese women for the first 9 years after diagnosis.

CONCLUSION

Chinese women in the United States have superior breast cancer–specific survival compared with White women. The reason for the observed difference is not clear. Differences in demographic and tumor features between Chinese and White women with breast cancer may contribute to the disparity, as may the possibility of intrinsic biologic differences.

Abstract 878: Contraceptive use and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers: A prospective cohort study

Background: Oral contraceptive use is associated with a significantly reduced risk of ovarian cancer among BRCA1 and BRCA2 mutation carriers. To date, there have been no prospective analyses of this relationship, and the impact of other types of contraception (e.g. intrauterine device (IUD), implant, patch, injection) on BRCA-associated ovarian cancer risk is unknown. The goal of this study is to prospectively evaluate the relationship between types of contraception and ovarian cancer incidence in women with a BRCA1 or BRCA2 mutation.

Methods: The longitudinal study included 3,298 eligible BRCA1/2 mutation carriers. Self-reported information regarding contraceptive use, including medication name, start year, end year, duration of use and method of administration were collected by biennial questionnaire. Women were classified according to history of contraceptive use (ever/never), duration of use, contraceptive method, calendar year of initiation and time since last use. Time-dependent Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) of ovarian cancer associated with each contraceptive method.

Results: There were 84 incident ovarian cancer cases diagnosed over a mean follow-up period of 5.1 years. There was no significant association between ever use of an IUD (HR: 0.78; 95% CI: 0.28-2.14) and risk of ovarian cancer compared to IUD never users. Ongoing analyses will focus on the relationships between other contraceptive methods, formulations and duration of use on ovarian cancer risk, further stratified by histology and site of origin.

Conclusions: Preliminary findings from this prospective analysis suggest that IUD use may not be protective among BRCA1/2 mutation carriers. Ongoing results will elucidate the impact of contraceptive formulation and method on ovarian cancer risk to inform clinical recommendations surrounding the use of contraceptive agents for chemoprevention in high risk women.

Citation Format: Yue Yin Xia, Jan Lubinski, Barry Rosen, Pal Moller, Andrea Eisen, Peter Ainsworth, Leigha Senter, Louise Bordeleau, Susan L. Neuhausen, Christian F. Singer, Jennifer Brooks, Ping Sun, Steven A. Narod, Joanne Kotsopoulos. Contraceptive use and ovarian cancer risk in BRCA1 and BRCA2 mutation carriers: A prospective cohort study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 878.

Abstract 857: Evaluating the relationship between arsenic exposure and cancer risk in Canada

Background: Arsenic is an established carcinogen for cancers of the skin, bladder and lungs; it is also the most prevalent environmental toxin, resulting in all Canadians being exposed to some extent. In a recent prospective study of a low-exposure population, our team found that women in the highest quartile of circulating arsenic had a significant 13-fold increased risk of developing breast cancer, compared to the lowest quartile. This suggests that even at low-doses, arsenic may be an important risk factor for breast, and potentially other cancers not previously recognized. To date, the sources of arsenic in Canada, a low-exposure population, are unclear.

Objectives: To describe the status of arsenic exposure, identify the key predictors of arsenic status, and evaluate the relationship between arsenic exposure and cancer risk within the Canadian population.

Methods: Using data from Cycles 1-5 (2007-2017) of the Canadian Health Measures Survey (CHMS), exposure data (e.g., diet, water), demographic information, and urinary arsenic biomarkers will be analyzed. The CHMS is an ongoing, nationally representative survey, collecting objective health measures and food intake information from participants in biennial cycles. Data will be described using weighted percentages or means, and arsenic levels (total and speciated urinary arsenic metabolite concentrations) will be reported by percentile. Weighted multivariate regression models will be used to identify predictors of total urinary arsenic. Linkage to the Canadian Cancer Registry will be performed to ascertain incident cancers, and Cox proportional hazards regression used to estimate the relationship between arsenic status and cancer risk (total and site-specific).

Results: This analysis included 15,700 individuals, aged 18-80. The median total urinary arsenic level was 7.5 ug/g of creatinine. Significant predictors of total urinary arsenic levels were found to be weekly intake of fish and seafood (β= 0.3, 95%CI 0.27,0.33, P &lt; 0.001), grains (β=-0.02, 95%CI -0.02, -0.01, P&lt; 0.001) and consumption of well and/or cistern water (β = 0.13, 95%CI 0.04, 0.22, P=0.005). Linkage and data analysis are ongoing.

Impact: This work is the first to ascertain national exposure estimates to an environmental carcinogen. Fish, seafood, grains, and consumption of well and/or cistern water represent significant predictors of total urinary arsenic levels in Canada. Ultimately, this information is needed to develop critical population-level intervention strategies to reduce the Canadian, and global burden of cancer.

Citation Format: Katherine Pullella, Shelley A. Harris, John R. McLaughlin, Jan Lubinski, Steven A. Narod, Joanne Kotsopoulos. Evaluating the relationship between arsenic exposure and cancer risk in Canada [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 857.

An evaluation of memory and attention in BRCA mutation carriers using an online cognitive assessment tool

BACKGROUND

The objective of this study was to evaluate the impact of various surgical, hormonal, and lifestyle factors on memory and attention in women with a BRCA1 or BRCA2 mutation.

METHODS

BRCA mutation carriers enrolled in a longitudinal study were invited to complete an online brain health assessment tool designed to screen for cognitive deficits. Four measures of memory and executive attention were assessed individually, and an overall score was compiled adjusting for age. Exposures, including preventive surgery, hormone use, and lifestyle factors, were captured by questionnaire. Performance on each of the 5 subtasks was analyzed according to various exposures. Analysis of covariance was used to compare overall scores.

RESULTS

In total, 880 women completed the online cognitive assessment. The average age of the participants was 54 years (range, 23-86 years). The mean overall test score was 54.4 (range, 0-93). The individual subtask scores declined with age at test completion (P < .0001) and increased with level of education (P ≤ .01). Women who underwent a preventive oophorectomy had a significantly higher overall score compared with women who did not undergo this surgery (55.5 vs 50.5; P = .01). Reconstructive breast surgery was also associated with a higher overall score (56.5 vs 52.3; P = .005). Chemotherapy and hormone-replacement therapy were not predictive of the overall score.

CONCLUSIONS

These findings are reassuring to high-risk women who undergo early surgical menopause for their cancer predisposition. Further studies are needed to evaluate cognitive function over time when memory deficits become more prevalent.

Factors associated with use of hormone therapy after preventive oophorectomy in BRCA mutation carriers

OBJECTIVE

Bilateral salpingo-oophorectomy (oophorectomy) is recommended to women with a germline BRCA1 or BRCA2 mutation before natural menopause to prevent ovarian and fallopian tube cancer. The adverse effects of early surgical menopause are well established. Although many of the side effects can be ameliorated by the use of hormone therapy (HT); use of HT in this group of predominantly young patients remains suboptimal. The goal of this study was to identify the frequency of HT use, as well as predictors of HT uptake in BRCA mutation carriers who underwent preventive oophorectomy before natural menopause.

METHODS

Eligible participants were identified from a longitudinal study of BRCA mutation carriers. We included premenopausal women with no personal history of cancer who underwent oophorectomy before age 50 and who had a minimum of 2 years of follow-up. Detailed information on HT use and other important variables was collected by a research questionnaire every 2 years. Descriptive statistics were used to evaluate the use of HT in various subgroups.

RESULTS

A total of 793 women with a BRCA1 or BRCA2 mutation were included in this analysis. The mean age at oophorectomy was 42 years (range 28-49). Sixty-one percent of the women reported using HT after oophorectomy. Factors associated with HT use included young age at surgery, a high level of education and preventive mastectomy.

CONCLUSIONS

The uptake of HT after oophorectomy in women with a BRCA1 or BRCA2 mutation varies by age, education, and surgical history. Clinician and patient awareness may lead to better utilization of HT in women who undergo oophorectomy at an early age to help mitigate the adverse effects associated with surgical menopause.

Frequency of Contralateral Prophylactic Mastectomy in Breast Cancer Patients with a Negative BRCA1 and BRCA2 Rapid Genetic Test Result

BACKGROUND

There is an increasing desire for contralateral prophylactic mastectomy (CPM) among patients with unilateral breast cancer. It is unknown if risk assessment and genetic testing at the time of diagnosis will aid women in their surgical choice. We report on the uptake and predictors of CPM in women receiving a negative genetic test result for BRCA1 and BRCA2 mutations before surgery.

METHODS

Women diagnosed with breast cancer between June 2013 and May 2018 were recruited from four academic health sciences centers in Toronto, Canada. Genetic counseling (risk assessment) and genetic testing was performed prior to surgery. Women were asked about their surgical preference before surgery. At 1 year post-surgery we asked what surgery was completed. This study reports on women who received a negative BRCA1/BRCA2 result.

RESULTS

A total of 766 women with a mean age of 46 years (range 21-82) were included in the analysis. Before genetic counseling and testing, 37% of the women were undecided or leaning towards CPM; however, after receiving a negative BRCA test, 15% of the women opted for CPM. Thirty percent of women whose mother died of breast cancer elected for CPM, compared with 15% of women whose mother did not die of breast cancer (p = 0.03).

CONCLUSIONS

Women receiving a risk assessment and negative BRCA1/BRCA2 genetic test result before surgery use this information to guide their surgical decision. Uptake of CPM for women who were planning on CPM before genetic testing decreases after receiving a negative BRCA1/BRCA2 genetic test result.

Gene Sequencing for Pathogenic Variants Among Adults With Breast and Ovarian Cancer in the Caribbean

IMPORTANCE

Rates of breast and ovarian cancer are high in the Caribbean; however, to date, few published data quantify the prevalence of inherited cancer in the Caribbean population.

OBJECTIVE

To determine whether deleterious variants in genes that characterize the hereditary breast and ovarian cancer syndrome are associated with the development of breast and ovarian cancer in the English- and Creole-speaking Caribbean populations.

DESIGN, SETTING, AND PARTICIPANTS

This multisite genetic association study used data from germline genetic test results between June 2010 and June 2018 in the Bahamas, Cayman Islands, Barbados, Dominica, Jamaica, Haiti, and Trinidad and Tobago. Next-generation sequencing on a panel of 30 genes and multiplex ligation-dependent probe amplification (BRCA1 and BRCA2) were performed. Medical records were reviewed at time of study enrollment. Women and men diagnosed with breast and ovarian cancer with at least 1 grandparent born in the participating study sites were included; 1018 individuals were eligible and consented to participate in this study. Data were analyzed from November 4, 2019, to May 6, 2020.

EXPOSURES

Breast and/or ovarian cancer diagnosis.

MAIN OUTCOMES AND MEASURES

Rate of inherited breast and ovarian cancer syndrome and spectrum and types of variants.

RESULTS

Of 1018 participants, 999 (98.1%) had breast cancer (mean [SD] age, 46.6 [10.8] years) and 21 (2.1%) had ovarian cancer (mean [SD] age, 47.6 [13.5] years). Three individuals declined to have their results reported. A total of 144 of 1015 (14.2%) had a pathogenic or likely pathogenic (P/LP) variant in a hereditary breast and ovarian cancer syndrome gene. A total of 64% of variant carriers had P/LP variant in BRCA1, 23% in BRCA2, 9% in PALB2 and 4% in RAD51C, CHEK2, ATM, STK11 and NBN. The mean (SD) age of variant carriers was 40.7 (9.2) compared with 47.5 (10.7) years in noncarriers. Individuals in the Bahamas had the highest proportion of hereditary breast and ovarian cancer (23%), followed by Barbados (17.9%), Trinidad (12%), Dominica (8.8%), Haiti (6.7%), Cayman Islands (6.3%), and Jamaica (4.9%). In Caribbean-born women and men with breast cancer, having a first- or second-degree family member with breast cancer was associated with having any BRCA1 or BRCA2 germline variant (odds ratio, 1.58; 95% CI, 1.24-2.01; P < .001). A BRCA1 vs BRCA2 variant was more strongly associated with triple negative breast cancer (odds ratio, 6.33; 95% CI, 2.05-19.54; P = .001).

CONCLUSIONS AND RELEVANCE

In this study, among Caribbean-born individuals with breast and ovarian cancer, 1 in 7 had hereditary breast and ovarian cancer. The proportion of hereditary breast and ovarian cancer varied by island and ranged from 23% in the Bahamas to 4.9% in Jamaica. Each island had a distinctive set of variants.

Blood cadmium levels as a marker for early lung cancer detection

BACKGROUND

We assessed whether blood cadmium levels were associated with incident lung cancer and could be used in the context of a screening program for early-stage lung cancer.

MATERIAL AND METHODS

We measured blood cadmium levels among 205 lung cancer patients and 205 matched controls. Cases and controls were matched for sex, age and smoking history (total pack-years, years since cessation for former smokers).

RESULTS

The odds ratio for those in the highest quartile of cadmium level (versus lowest) was four-fold (OR = 4.41, 95 % CI:2.01-9.67, p < 0.01). The association was present in former smokers (OR = 16.8, 95 % CI:3.96-71.2, p < 0.01), but not in current smokers (OR = 1.23, 95 % CI: 0.34-4.38) or in never smokers (OR not defined). Among former smokers, the association was present in both early- and late-stage lung cancer.

CONCLUSION

Blood cadmium levels may be a marker to help with the early detection of lung cancer among former smokers.

Abstract PS7-39: Survival differences in chinese versus white women with breast cancer in the United States: A SEER-based analysis

Purpose: Several studies have reported lower breast cancer survival rates among Black women compared to White women, but less is known regarding outcomes in Chinese women. We compared survival rates for Chinese and White women with breast cancer in the Surveillance, Epidemiology, and End Results (SEER) database diagnosed between 2004 and 2015.

Methods: We conducted a cohort study of Chinese and White women with breast cancer diagnosed between 2004 to 2015 in the SEER18 registries database. We abstracted information on age and year of diagnosis, marital status, median household income, tumour size and grade, lymph node status, clinical stage, receptor status (estrogen, progesterone, and HER-2/neu receptor), surgical treatment (lumpectomy versus mastectomy), receipt of radiotherapy and chemotherapy, and death. Chinese and White women were compared for demographic, pathologic and treatment variables and differences were assessed using standardized differences. Our primary outcome was death from breast cancer. We compared crude breast cancer-specific mortality rates between the two ethnic groups. We also calculated adjusted hazard ratios (HR) in a propensity-matched design using the Cox proportional hazards model. Women were matched on the year of diagnosis and age at diagnosis (both within 2 years), tumour grade, nodal status, clinical stage, estrogen receptor status, HER2/neu status and propensity score. The propensity score accounted for marital status, household income, tumour size, progesterone receptor status and surgical procedure. A log-rank test was used to compare differences between groups using the Kaplan-Meier method. P values &lt; .05 were considered statistically significant.

Results: There were 7,553 Chinese women (1.8%) and 414,618 White women (98.2%) with stage I-IV breast cancer registered in the SEER database. There were only small differences in tumour size, stage at presentation, node-positivity, the proportion of HER2-positive cancers, and the treatments received. Among women with stage I-IIIC breast cancer, 10-year breast cancer-specific survival was 88.8% for Chinese women, compared with 85.6% for White women. The cumulative mortality from breast cancer after 11 years of follow-up was 12.9% for Chinese women and 16.4% for White women; crude HR 0.73 (95% CI 0.67 - 0.80; P &lt; .0001). In the first nine years after diagnosis, annual mortality rates are higher in White women than for Chinese women. Following the first nine years after diagnosis, the annual mortality rate for Chinese women then exceeds that of White women. In a propensity-matched analysis, the cumulative mortality from breast cancer after 11 years of follow-up was 8.9% for Chinese women and 11.9% for White women (P = .0002). The adjusted hazard ratio was 0.71 (95% CI 0.62 - 0.81) and was similar to the crude hazard ratio of 0.73 (95% CI 0.67 - 0.90). The adjusted hazard ratios demonstrate that Chinese women had better survival than White women in subgroups defined by age of diagnosis, tumour size and grade, clinical stage, nodal status and estrogen receptor status. The largest effects were observed for stage I cancers (HR 0.57, 95% CI 0.36-0.90) and for node-negative cancers (HR 0.61, 95% CI 0.46-0.82).

Conclusion: Chinese women diagnosed with breast cancer in the SEER database between 2004 to 2015 had significantly better survival rates than White women with breast cancer. Over a 10-year follow-up period, Chinese women with stage I-IIIC breast cancer experienced a 30% lower risk of death than a comparable group of White women with breast cancer. The observed difference cannot be accounted for by clinical presentation or by differences in treatment and suggests that there are intrinsic biological differences in breast cancer between Chinese and White women.

Citation Format: David Wai Lim, Vasily Giannakeas, Steven A Narod. Survival differences in chinese versus white women with breast cancer in the United States: A SEER-based analysis [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-39.

Bilateral Mastectomy in Women With Unilateral Breast Cancer: A Review

Importance

Rates of bilateral mastectomy continue to increase in average-risk women with unilateral in situ and invasive breast cancer. Contralateral prophylactic mastectomy rates increased from 5% to 12% of all operations for breast cancer in the US from 2004 to 2012. Among women having mastectomy, rates of contralateral prophylactic mastectomy have increased from less than 2% in 1998 to 30% in 2012.

Observations

The increased use of breast magnetic resonance imaging and genetic testing has marginally increased the number of candidates for bilateral mastectomy. Most bilateral mastectomies are performed on women who are at no special risk for contralateral cancer. The true risk of contralateral breast cancer is not associated with the decision for contralateral prophylactic mastectomy; rather, the clinical factors associated with the probability of distant recurrence are associated with bilateral mastectomy. Several changes in society and health care delivery appear to act concurrently and synergistically. First, the anxiety engendered by a fear of cancer recurrence is focused on the contralateral cancer because this is most easily conceptualized and provides a ready target that can be acted upon. Second, the modern woman with breast cancer is supported by the surgeon and the social community of breast cancer survivors. Surgeons want to respect patient autonomy, despite guidelines discouraging bilateral mastectomy, and most women have their expenses covered by a third-party payer. Satisfaction with the results is high, but the association with improved psychosocial well-being remains to be fully understood.

Conclusions and Relevance

Reducing the use of medically unnecessary contralateral prophylactic mastectomy in women with nonhereditary, unilateral breast cancer requires a social change that addresses patient-, physician-, cultural-, and systems-level enabling factors. Such a transformation begins with educating clinicians and patients. The concerns of women who want preventive contralateral mastectomy must be explored, and women need to be informed of the anticipated benefits (or lack thereof) and risks. Areas requiring further study are considered.

The impacts of neoadjuvant chemotherapy and of cytoreductive surgery on 10-year survival from advanced ovarian cancer

OBJECTIVE

To compare the long-term survival outcomes for women with advanced ovarian cancer treated with chemotherapy either before or after surgery (neoadjuvant chemotherapy vs primary cytoreductive surgery) at a single tertiary cancer center.

METHODS

Retrospective cohort study of 326 patients with Stage IIIC or IV high-grade serous ovarian cancer who received neoadjuvant chemotherapy or primary cytoreductive surgery between 2001 and 2011. Clinical treatments were recorded and 10-year survival rates were measured.

RESULTS

A total of 183 women (56.1%) underwent primary cytoreductive surgery and 143 women (43.9%) received neoadjuvant chemotherapy. Women who received neoadjuvant chemotherapy were more likely to have no residual disease than those who underwent primary cytoreductive surgery (51.4% vs 41.5%; P = 0.030) but experienced inferior 10-year overall survival (9.1% vs 19.3%; P < 0.001). Among those who had primary cytoreductive surgery, those with no residual disease had superior 10-year overall survival than those who had any evidence of residual disease (36.0% vs 7.2%; P < 0.001).

CONCLUSION

Among women with advanced ovarian cancer, those who underwent primary cytoreductive surgery had better survival than those who received neoadjuvant chemotherapy. Neoadjuvant chemotherapy should be reserved for those in whom optimal primary cytoreductive surgery is not feasible.

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.

Assessment of Secondary Sarcomas Among Patients With Cancer of the Abdomen or Pelvis Who Received Combinations of Surgery, Radiation, and Chemotherapy vs Surgery Alone

IMPORTANCE

The association of radiation and chemotherapy with the development of secondary sarcoma is known, but the contemporary risk has not been well characterized for patients with cancers of the abdomen and pelvis.

OBJECTIVE

To compare the risk of secondary sarcoma among patients treated with combinations of surgery, radiation, or chemotherapy with patients treated with surgery alone and the general population.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included 173 580 patients in Ontario, Canada, with nonmetastatic cancer of the prostate, bladder, colon, rectum or anus, cervix, uterus, or testis. Patients were enrolled from January 1, 2002, to January 31, 2017. Data analysis was conducted from March 1, 2019, to January 31, 2020.

EXPOSURES

Treatment combinations of radiation, chemotherapy, and surgery.

MAIN OUTCOME AND MEASURES

Diagnosis of sarcoma based on histologic codes from the Ontario Cancer Registry. Time to sarcoma was compared using a cause-specific proportional hazard model.

RESULTS

Of 173 580 patients, most were men (125 080 [72.1%]), and the largest group was aged between 60 and 69 years (58 346 [33.6%]). Most patients had genitourinary cancer (86 235 [51.4%]) or colorectal cancer (69 241 [39.9%]). Overall, 64 301 (37.1%) received surgery alone, 51 220 (29.5%) received radiation alone, 15 624 (9.0%) were treated with radiation and chemotherapy, 15 252 (8.8%) received radiation with surgery, and 11 822 (6.8%) received all 3 treatments. A total of 332 patients (0.2%) had sarcomas develop during a median (interquartile range) follow-up of 5.7 (2.2-8.9) years. The incidence of sarcoma was 0.3% among those who underwent radiation alone (138 of 51 220) and radiation with chemotherapy (40 of 15 624), 0.2% among those who received radiation and surgery (36 of 15 252) and all 3 modalities (25 of 11 822), and 0.1% among those who received surgery with chemotherapy (13 of 14 861) and surgery alone (80 of 64 801). Compared with a reference group of patients who had surgery alone, the greatest risk of sarcoma was found among patients who underwent a combination of radiation and chemotherapy (cause-specific relative hazard [csRH], 4.07; 95% CI, 2.75-6.01; P < .001), followed by patients who had radiation alone (csRH, 2.35; 95% CI, 1.77-3.12; P < .001), radiation with surgery (csRH, 2.33; 95% CI, 1.57-3.46; P < .001), and all 3 modalities (csRH, 2.27; 95% CI, 1.44-3.58; P < .001). In the general population, 7987 events occurred during 46 554 803 person-years (17.2 events per 100 000 person-years). The standardized incidence ratio for sarcoma among patients treated with radiation compared with the general population was 2.41 (95% CI, 1.57-3.69; 41.3 events per 100 000 person-years). The annual number of cases of sarcoma increased from 2009 (15 per 100 000 persons) to 2016 (32 per 100 000 persons), but the annual rate did not change during the study period.

CONCLUSIONS AND RELEVANCE

In this cohort study, patients treated with radiation or chemotherapy for abdominopelvic cancers had an increased rate of sarcoma. Although the absolute rate is low, patients and physicians should be aware of this increased risk of developing sarcoma.

Rapid Genetic Testing for BRCA1 and BRCA2 Mutations at the Time of Breast Cancer Diagnosis: An Observational Study

BACKGROUND

This study aimed to evaluate the impact of rapid genetic testing (RGT) for BRCA1 and BRCA2 at the time of breast cancer diagnosis on treatment choices. Bilateral mastectomy for the treatment of breast cancer in women with a BRCA1 or BRCA2 mutation offers a reduction in the risk of contralateral breast cancer. It is unclear whether offering RGT at the time of breast cancer diagnosis has an impact on women's surgical decision-making.

METHODS

Women with breast cancer diagnosed between June 2013 and May 2018 were recruited from four academic health sciences centers in Toronto, Canada. The participants completed a questionnaire before genetic testing, then one week and one year after disclosure of the genetic test result. Before surgery, RGT was performed. Diagnostic, pathologic, and treatment data were compared between those with and those without a BRCA mutation.

RESULTS

The study enrolled 1007 women who consented to RGT. The mean age of the participants was 46.3 years, and the median time to result disclosure was 10 days. A BRCA mutation was found in 6% of the women. The women with a BRCA mutation were significantly more likely to elect for bilateral mastectomy than the women without a BRCA mutation (p < 0.0001). Of the BRCA-positive patients, 95.7% reported that they used their genetic test result to make a surgical decision.

CONCLUSIONS

The women provided with RGT at the time of breast cancer diagnosis use the genetic information to make treatment decisions, and the majority of those identified with a BRCA mutation elect for a bilateral mastectomy.

Patient reported experiences following laparoscopic prophylactic bilateral salpingo-oophorectomy or salpingectomy in an ambulatory care hospital

Women at risk of developing ovarian cancer because of a BRCA1 or BRCA2 pathogenic variant are candidates for prophylactic bilateral salpingo-oophorectomy (BSO). While BSO surgeries are routinely performed, to our knowledge there are no studies that have examined patient-reported experiences following laparoscopic BSO performed in an ambulatory care setting. The objective of this study was to examine whether women undergoing prophylactic laparoscopic BSO felt they were adequately informed about post-operative outcomes. A telephone interview was conducted among 46 women undergoing laparoscopic BSO to collect detailed information regarding surgical outcomes, complications, symptoms, and time to return to daily activities. The average age at surgery was 45.0 years (range 34-66) and 67% of women underwent BSO prior to age 50. The mean reported hospital stay was 7.2 h (range 4-12 h) and at time of discharge, 78% of the women felt well enough to go home. None of the women required a readmission to hospital. Forty-three percent (n = 20) of the women did not feel well informed about what to expect post-operatively. Most of the patient-reported outcomes (including pain, vaginal bleeding, and nausea/vomiting) were expected and patient-reported menopausal symptoms were more common among women who were premenopausal at surgery. In terms of returning to regular activities, premenopausal women (n = 36) resumed sexual activity on average at 43 days (range 2-365), which is later than postmenopausal women (n = 15) at 19 days (range 7-30). On average, women returned to full-time work in 16 days (range 1-56 days). Despite patients receiving pre-surgery counselling, our findings suggest that there is a need to provide supplemental, reinforcing patient materials in preparing patients for what to expect after surgery.

Breast cancer survival in Nordic BRCA2 mutation carriers-unconventional association with oestrogen receptor status

Background

The natural history of breast cancer among BRCA2 carriers has not been clearly established. In a previous study from Iceland, positive ER status was a negative prognostic factor. We sought to identify factors that predicted survival after invasive breast cancer in an expanded cohort of BRCA2 carriers.

Methods

We studied 608 women with invasive breast cancer and a pathogenic BRCA2 mutation (variant) from four Nordic countries. Information on prognostic factors and treatment was retrieved from health records and by analysis of archived tissue specimens. Hazard ratios (HR) were estimated for breast cancer-specific survival using Cox regression.

Results

About 77% of cancers were ER-positive, with the highest proportion (83%) in patients under 40 years. ER-positive breast cancers were more likely to be node-positive (59%) than ER-negative cancers (34%) (P < 0.001). The survival analysis included 584 patients. Positive ER status was protective in the first 5 years from diagnosis (multivariate HR = 0.49; 95% CI 0.26–0.93, P = 0.03); thereafter, the effect was adverse (HR = 1.91; 95% CI 1.07–3.39, P = 0.03). The adverse effect of positive ER status was limited to women who did not undergo endocrine treatment (HR = 2.36; 95% CI 1.26–4.44, P = 0.01) and patients with intact ovaries (HR = 1.99; 95% CI 1.11–3.59, P = 0.02).

Conclusions

The adverse effect of a positive ER status in BRCA2 carriers with breast cancer may be contingent on exposure to ovarian hormones.

Mutations in ATM, NBN and BRCA2 predispose to aggressive prostate cancer in Poland

In designing national strategies for genetic testing, it is important to define the full spectrum of pathogenic mutations in prostate cancer (PCa) susceptibility genes. To investigate the frequency of mutations in PCa susceptibility genes in Polish familial PCa cases and to estimate gene-related PCa risks and probability of aggressive disease, we analyzed the coding regions of 14 genes by exome sequencing in 390 men with familial prostate cancer and 308 cancer-free controls. We compared the mutation frequencies between PCa cases and controls. We also compared clinical characteristics of prostate cancers between mutation carriers and noncarriers. Of the 390 PCa cases, 76 men (19.5%) carried a mutation in BRCA1, BRCA2, NBN, ATM, CHEK2, HOXB13, MSH2 or MSH6 genes. No mutations were found in BRIP1, PTEN, TP53, MLH1, PMS2 and SPOP. Significant associations with familial PCa risk were observed for CHEK2, NBN, ATM, and HOXB13. High-grade (Gleason 8-10) tumors were seen in 56% of BRCA2, NBN or ATM carriers, compared to 21% of patients who tested negative for mutations in these genes (OR = 4.7, 95% CI 2.0-10.7, P = .0003). In summary, approximately 20% of familial prostate cancer cases in Poland can be attributed to mutations in eight susceptibility genes. Carriers of mutations in BRCA2, NBN and ATM develop aggressive disease and may benefit from intensified screening and/or chemotherapy.

Association of a Diagnosis of Ductal Carcinoma In Situ With Death From Breast Cancer

IMPORTANCE

It is not clear to what extent a diagnosis of ductal carcinoma in situ (DCIS) impacts a woman's lifetime risk of dying of breast cancer. Under ideal circumstances, treatment will eliminate the risk of invasive ipsilateral recurrence and prevent subsequent mortality from breast cancer. The risk of dying of breast cancer after a diagnosis of DCIS had not been compared with that of women without cancer in the general population.

OBJECTIVE

To determine the risk of death from breast cancer in a large cohort of patients treated for DCIS and to compare the risk with that of women in the general population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included data for women who had first primary DCIS diagnosed between 1995 and 2014 from the Surveillance, Epidemiology and End Results (SEER) registries database. Women with DCIS underwent surgical treatment, and approximately half also received radiotherapy. These women were followed from the date of DCIS diagnosis until death from breast cancer or date of last follow-up. Women in the general population without breast cancer were analyzed as controls. Follow-up information was available up to December 2016. The data were analyzed in March 2020.

EXPOSURES

Patients with DCIS who underwent surgical treatment.

MAIN OUTCOMES AND MEASURES

Breast cancer death was the main outcome. Standardized mortality ratios were estimated by comparing deaths from breast cancer among women diagnosed with DCIS with expected deaths from breast cancer among women in the general population who did not have cancer. Expected probability of death from breast cancer in the general population was calculated by an incidence-based mortality approach using standardized SEER-based incidence and case-fatality rates. Probability of breast cancer death was estimated based on the assumption that a cancer-free control was cancer free on the date the woman with DCIS was diagnosed and was studied until the end of follow-up.

RESULTS

A total of 144 524 women diagnosed with first primary DCIS were included (mean [SD] age at diagnosis, 57.4 [11.0] years). There were 1540 deaths from breast cancer in the cohort. Based on SEER-based incidence and case-fatality rates, 458 breast cancer deaths were expected in an equivalent number of cancer-free women from the general population with equal follow-up. The standardized mortality ratio for death from breast cancer among women with DCIS was 3.36 (95% CI, 3.20-3.53). The elevated risk of death persisted more than 15 years after diagnosis.

CONCLUSIONS AND RELEVANCE

In the population studied, the risk of dying of breast cancer was increased 3-fold after a diagnosis of DCIS. This suggests that our current treatment focus on preventing invasive recurrence is insufficient to eliminate all deaths from breast cancer after DCIS.

Prevalence of Recurrent Mutations Predisposing to Breast Cancer in Early-Onset Breast Cancer Patients from Poland

There are twenty recurrent mutations in six breast-cancer-predisposing genes in Poland (BRCA1, BRCA2, CHEK2, PALB2, NBN, and RECQL). The frequencies of the twenty alleles have not been measured in a large series of early-onset breast cancer patients from Poland unselected for family history. We genotyped 2464 women with breast cancer diagnosed below age 41 years for twenty recurrent germline mutations in six genes, including BRCA1, BRCA2 CHEK2, PALB2, NBN, and RECQL. A mutation in one of the six genes was identified in 419 of the 2464 early-onset breast cancer cases (17%), including 22.4% of those cases diagnosed below age 31. The mutation frequency was 18.8% for familial breast cancer cases and 6% for non-familial cases. Among women with breast cancer below age 31, the mutation frequency was 23.6% for familial cases and 17.4% in non-familial cases. The majority of mutations (76.2%) were seen in BRCA1 and BRCA2. In Poland, a panel of twenty recurrent mutations in six genes can identify a genetic basis for a high percentage of early-onset cases and testing is recommended for all women with breast cancer at age 40 or below.

Long-term outcomes following a diagnosis of ovarian cancer at the time of preventive oophorectomy among BRCA1 and BRCA2 mutation carriers

INTRODUCTION

Preventive bilateral salpingo-oophorectomy is the most effective means of reducing the risk of ovarian cancer among women with an inherited BRCA1 or BRCA2 mutation. Some women are diagnosed with an invasive cancer (ovarian or fallopian tube) at the time of preventive surgery, referred to as an 'occult' cancer. The survival experience of these women is not known.

METHODS

We estimated the 10-year survival for 52 BRCA mutation carriers diagnosed with an occult ovarian or fallopian tube cancer at the time of preventive bilateral salpingo-oophorectomy.

RESULTS

The mean age at diagnosis was 51.6 (range 33-69) years. All were serous cancers (although 14 were missing information on histologic subtype). Of the 20 cases with information available on stage at diagnosis, 10 were stage I, 1 was stage II, and 9 were stage III (n=32 missing). After a mean of 6.8 years, 12 women died (23%). The 10-year all-cause survival was 74%.

CONCLUSION

Although based on only 52 cases, these findings suggest a more favorable prognosis for BRCA mutation carriers diagnosed with an occult rather than incident disease.

Association between genetically predicted polycystic ovary syndrome and ovarian cancer: a Mendelian randomization study

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder with an estimated prevalence of 4-21% in reproductive aged women. Recently, the Ovarian Cancer Association Consortium (OCAC) reported a decreased risk of invasive ovarian cancer among women with self-reported PCOS. However, given the limitations of self-reported PCOS, the validity of these observed associations remains uncertain. Therefore, we sought to use Mendelian randomization with genetic markers as a proxy for PCOS, to examine the association between PCOS and ovarian cancer.

METHODS

Utilizing 14 single nucleotide polymorphisms (SNPs) previously associated with PCOS we assessed the association between genetically predicted PCOS and ovarian cancer risk, overall and by histotype, using summary statistics from a previously conducted genome-wide association study (GWAS) of ovarian cancer among European ancestry women within the OCAC (22 406 with invasive disease, 3103 with borderline disease and 40 941 controls).

RESULTS

An inverse association was observed between genetically predicted PCOS and invasive ovarian cancer risk: odds ratio (OR)=0.92 [95% confidence interval (CI)=0.85-0.99; P = 0.03]. When results were examined by histotype, the strongest inverse association was observed between genetically predicted PCOS and endometrioid tumors (OR = 0.77; 95% CI = 0.65-0.92; P = 0.003). Adjustment for individual-level body mass index, oral contraceptive use and parity did not materially change the associations.

CONCLUSION

Our study provides evidence for a relationship between PCOS and reduced ovarian cancer risk, overall and among specific histotypes of invasive ovarian cancer. These results lend support to our previous observational study results. Future studies are needed to understand mechanisms underlying this association.

Prophylactic salpingectomy for the prevention of ovarian cancer: Who should we target?

Ovarian cancer is the most fatal gynecologic malignancy (50% 5-year survival) due to a typically advanced stage at diagnosis and a high rate of recurrence. Chemoprevention options are limited, and few interventions have been shown to reduce cancer risk or mortality. Emerging data support the model that fallopian tubes are the site of origin for a proportion of high-grade serous cancers. This implies that a subset of cancers may be prevented by removing the fallopian tubes while leaving the ovaries intact. Accordingly, there has been shift in clinical practice for average risk women; some now recommend removal of both the fallopian tubes only instead of tubal ligation for sterilization or at the time of benign gynecologic surgery. This has been termed opportunistic salpingectomy and represents a means of decreasing the burden of ovarian cancer by preventing cancers that arise in the fallopian tubes. There have been no detailed, prospective reports that have estimated ovarian cancer risk reduction with opportunistic salpingectomy, neither among women at baseline population risk nor among women at a high risk of developing the disease. The situation is complicated for women with a BRCA mutation-bilateral salpingo-oophorectomy is a proven means of risk reduction and salpingectomy alone is not the standard of care. Based on the existing data, salpingectomy alone should only be reserved for women with a lifetime risk of ovarian cancer of less than 5%.

Abstract P5-07-07: A generalizable relationship between mortality and time-to-death among breast cancer patients can be explained by tumor dormancy

Background: Women with ER-positive breast cancer may recur as late as twenty years post diagnosis. The reason for this delayed recurrence is unknown. We studied survival patterns, including time-to-death in 123,705 women with stage I to III invasive breast cancer, enrolled in the SEER database. We sought to determine if time from diagnosis to death could be explained by variation in tumor dormancy.

Methods: We divided the cohort into ten classes based on their 20-year risks of death from breast cancer. Probability of death at 20 years was estimated for each patient using year of diagnosis, patient characteristics (age, race, household income), tumor characteristics (grade, tumor size, nodal status, stage, ER and PR-status) and treatment (radiotherapy, chemotherapy). The 20-year mortality for women in the highest risk decile (decile 10) was 69% versus 5% for women in the lowest decile (decile 1). We define a variable α which represents the annual rate of reactivation from tumor dormancy. Using the highest risk decile as a reference distribution, we determined what α value gives the best fit for the time-to-death distribution of each decile. As a complementary analysis we performed quantile regression to determine independent predictors of time-to-death among women who died from breast cancer.

Results: The duration of tumor dormancy was much longer, on average, for ER-positive breast cancers than for ER-negative breast cancers. Time at peak mortality rate monotonically decreased by decile, ranging from 19 years post-diagnosis in the lowest risk decile to two years post-diagnosis in the highest risk decile (Table 1). The difference in the time-to-death distributions by decile could be explained by the variable α which represents the annual rate of reactivation from tumor dormancy.

In the regression analysis, ER-positive breast cancers had a median time-to-death 3.67 years longer than ER-negative breast cancers (Table 2). However, this effect was attenuated by risk factors correlated with ER status (adjusted difference 1.76 years). Notable independent predictors of time-to-death include ethnicity, tumor size, grade, nodal status and PR-status.

Conclusion: Reactivation from tumor dormancy appears to occur at random wherein the rate of tumor activation is correlated with probability of death from breast cancer. This model may explain the very long time to cancer recurrence in women with ER-positive node-negative breast cancers. The clinical course of women with low-risk breast cancer is inherently unpredictable.

Table 1: Factors related to breast cancer mortality and time-to-death by decile.Risk DecileNumber of patients (N)Annual death rate (per 100 person-years)20-year actuarial mortality (%)Peak mortality time (years)Median time-to-death (years)10th percentile time-to-death (years)90th percentile time-to-death (years)Optimal α (reactivations per person-year)112,3700.255.3%19.012.24.018.70.10212,3710.438.6%19.511.04.318.40.16312,3700.6011.3%9.510.33.517.60.20412,3710.7413.2%5.58.93.016.70.32512,3700.9016.0%3.58.62.617.40.32612,3711.1720.0%4.08.12.616.90.35712,3711.5124.8%3.07.62.316.70.41812,3702.1231.7%3.06.41.915.90.74912,3713.2242.5%2.55.61.714.81.291012,3706.6463.0%2.03.81.112.3InF (Ref.)

Table 2: Predictors of time-to-death in breast cancer patients.PredictorValueUnadjustedAdjustedMedian time-to-death (years)Difference* (years)Difference (years)**POverall/ Reference5.6713.05***&lt;.0001Year of diagnosis19905.42Reference19915.670.250.170.360919925.670.250.220.289919935.580.170.350.059919946.000.580.530.0054Age at diagnosis&lt;505.58Reference50-595.920.330.070.580760-696.170.58-0.060.655170-805.25-0.33-1.18&lt;.0001EthnicityWhite5.75ReferenceBlack4.33-1.42-0.320.009East Asian6.670.920.930.0058Southeast Asian6.080.330.090.8208Other/Unknown6.170.420.420.4176Tumor size (cm)&lt;1cm8.33Reference1-2cm7.33-1.00-0.650.07922-3cm5.58-2.75-1.42&lt;.00013-5cm4.75-3.58-1.76&lt;.00015+cm3.83-4.50-2.16&lt;.0001Tumor gradeI11.17ReferenceII7.58-3.58-2.82&lt;.0001III4.25-6.92-4.78&lt;.0001IV3.92-7.25-5.18&lt;.0001Unknown6.25-4.92-3.57&lt;.0001Nodal statusN06.83ReferenceN15.67-1.17-0.69&lt;.0001N25.00-1.83-1.08&lt;.0001N33.83-3.00-2.03&lt;.0001Unknown2.42-4.42-2.32&lt;.0001ER statusPositive7.17ReferenceNegative3.50-3.67-1.76&lt;.0001PR statusPositive7.25ReferenceNegative3.83-3.42-1.7&lt;.0001Unknown5.08-2.17-1.35&lt;.0001RadiotherapyNo5.42ReferenceYes6.080.670.260.0214Unknown5.08-0.33-0.470.1043ChemotherapyNo/Unknown6.58ReferenceYes5.17-1.42-0.310.0091*Difference in median time-to-death relative to reference value.**Independent difference in median time-to-death after adjusting for all covariates in table.***Median time-to-death of the reference group.

Citation Format: Vasily Giannakeas, Steven A Narod. A generalizable relationship between mortality and time-to-death among breast cancer patients can be explained by tumor dormancy [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-07-07.

Fine-mapping of 150 breast cancer risk regions identifies 191 likely target genes

Genome-wide association studies have identified breast cancer risk variants in over 150 genomic regions, but the mechanisms underlying risk remain largely unknown. These regions were explored by combining association analysis with in silico genomic feature annotations. We defined 205 independent risk-associated signals with the set of credible causal variants in each one. In parallel, we used a Bayesian approach (PAINTOR) that combines genetic association, linkage disequilibrium and enriched genomic features to determine variants with high posterior probabilities of being causal. Potentially causal variants were significantly over-represented in active gene regulatory regions and transcription factor binding sites. We applied our INQUSIT pipeline for prioritizing genes as targets of those potentially causal variants, using gene expression (expression quantitative trait loci), chromatin interaction and functional annotations. Known cancer drivers, transcription factors and genes in the developmental, apoptosis, immune system and DNA integrity checkpoint gene ontology pathways were over-represented among the highest-confidence target genes.

Serum selenium level and cancer risk: a nested case-control study

Background

Epidemiologic studies have demonstrated a relationship between selenium status and cancer risk among those with low selenium levels. It is of interest to prospectively evaluate the relationship between selenium and cancer among women who reside in a region with ubiquitously low selenium levels.

Methods

We performed a nested case-control study of baseline serum selenium levels and cancer risk using data and biological samples from 19,573 females that were participants in a biobanking initiative between 2010 and 2014 in Szczecin Poland. Cases included women with any incident cancer (n = 97) and controls (n = 184) were women with no cancer at baseline or follow-up. Serum selenium was quantified using mass spectroscopy.

Results

The odds ratio associated being below the cutoff of 70.0 μg/L compared to a level above 70.0 μg/L was 2.29 (95% CI 1.26–4.19; P = 0.007). The risks for women in the two middle categories were similar and suggests that the normal range be between 70 μg/L and 90 μg/L. There was evidence for an increased risk of cancer among women in the highest category of selenium levels (i.e., > 90 μg/L), but this association did not achieve statistical significance (OR = 1.63; 95%CI 0.63–4.19; P = 0.31).

Conclusions

Results from this study suggest that suggest that the optimum serum level of selenium in women living in Poland should be between 70 μg/L and 90 μg/L.

Countercurrents: The bias of choice

Of the several kinds of bias that might corrupt an epidemiology study, selection bias is the most insidious […]

Retesting of women who are negative for a BRCA1 and BRCA2 mutation using a 20-gene panel

BACKGROUND

The value of retesting women who previously tested negative for a pathogenic variant (mutation) in BRCA1 and BRCA2 using an expanded panel of breast and ovarian cancer genes is unclear.

METHODS

We studied 110 BRCA1/2-negative women who were retested using a panel of 20 breast and/or ovarian cancer susceptibility genes at the Advanced Molecular Diagnostics Laboratory (AMDL) at Mount Sinai Hospital in Toronto between March 2017 and March 2019. All patients had previously tested negative for BRCA pathogenic variants at the AMDL between January 2012 and March 2018 and were subsequently referred for retesting by their physician.

RESULTS

Overall, six pathogenic variants in genes other than BRCA1 and BRCA2 were found (prevalence 5.5%). There were two pathogenic variants found in RAD51C, and one found in each of BRIP1, PALB2, PMS2 and PTEN. The prevalence of pathogenic variants was 6.5% for women affected with cancer (6 of 93), including 4.9% for women with breast cancer (4 of 82) and 22.2% for women with ovarian cancer (2 of 9). None of the 17 unaffected women had a clinically significant or pathogenic variant. There were 44 women (40%) for whom the result of the panel test was inconclusive due to the detection of a variant of uncertain significance.

CONCLUSIONS

Our findings indicate that the retesting of BRCA1/2-negative individuals with an expanded panel of 20 breast and ovarian cancer genes can produce clinically relevant results, with a yield of 5.5% for pathogenic variants in genes other than BRCA1 and BRCA2.

Exome Sequencing in BRCA1- and BRCA2-Negative Greek Families Identifies MDM1 and NBEAL1 as Candidate Risk Genes for Hereditary Breast Cancer

Approximately 10% of breast cancer (BC) cases are hereditary BC (HBC), with HBC most commonly encountered in the context of hereditary breast and ovarian cancer (HBOC) syndrome. Although thousands of loss-of-function (LoF) alleles in over 20 genes have been associated with HBC susceptibility, the genetic etiology of approximately 50% of cases remains unexplained, even when polygenic risk models are considered. We focused on one of the least-studied European populations and applied whole-exome sequencing (WES) to 52 individuals from 17 Greek HBOC families, in which at least one patient was negative for known HBC risk variants. Initial screening revealed pathogenic variants in known cancer genes, including BARD1:p.Trp91* detected in a cancer-free individual, and MEN1:p.Glu260Lys detected in a BC patient. Gene- and variant-based approaches were applied to exome data to identify candidate risk variants outside of known risk genes. Findings were verified in a collection of Canadian HBOC patients of European ancestry (FBRCAX), in an independent group of Canadian BC patients (CHUM-BC) and controls (CARTaGENE), as well as in individuals from The Cancer Genome Atlas (TCGA) and the UK Biobank (UKB). Rare LoF variants were uncovered in MDM1 and NBEAL1 in Greek and Canadian HBOC patients. We also report prioritized missense variants SETBP1:c.4129G > C and C7orf34:c.248C > T. These variants comprise promising candidates whose role in cancer pathogenicity needs to be explored further.

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.

BRCA1 promoter methylation in peripheral blood is associated with the risk of triple-negative breast cancer

Methylation of the promoter of the BRCA1 gene in DNA derived from peripheral blood cells is a possible risk factor for breast cancer. It is not clear if this association is restricted to certain types of breast cancer or is a general phenomenon. We evaluated BRCA1 methylation status in peripheral blood cells from 942 breast cancer patients and from 500 controls. We also assessed methylation status in 262 paraffin-embedded breast cancer tissues. Methylation status was assessed using methylation-sensitive high-resolution melting and was categorized as positive or negative. BRCA1 methylation in peripheral blood cells was strongly associated with the risk of triple-negative breast cancer (TNBC) (odds ratio [OR] 4.70; 95% confidence interval [CI]: 3.13-7.07; p < 0.001), but not of estrogen-receptor positive breast cancer (OR 0.80; 95% CI: 0.46-1.42; p = 0.46). Methylation was also overrepresented among patients with high-grade cancers (OR 4.53; 95% CI: 2.91-7.05; p < 0.001) and medullary cancers (OR 3.08; 95% CI: 1.38-6.88; p = 0.006). Moreover, we detected a significant concordance of BRCA1 promoter methylation in peripheral blood and paired tumor tissue (p < 0.001). We found that BRCA1 promoter methylation in peripheral blood cells is associated with approximately five times greater risk of TNBC. We propose that BRCA1 methylation in blood-derived DNA could be a novel biomarker of increased breast cancer susceptibility, in particular for triple-negative tumors.

Inherited variants in XRCC2 and the risk of breast cancer

Background

XRCC2 participates in homologous recombination and in DNA repair. XRCC2 has been reported to be a breast cancer susceptibility gene and is now included in several breast cancer susceptibility gene panels.

Methods

We sequenced XRCC2 in 617 Polish women with familial breast cancer and found a founder mutation. We then genotyped 12,617 women with breast cancer and 4599 controls for the XRCC2 founder mutation.

Results

We identified a recurrent truncating mutation of XRCC2 (c.96delT, p.Phe32fs) in 3 of 617 patients with familial breast cancer who were sequenced. The c.96delT mutation was then detected in 29 of 12,617 unselected breast cancer cases (0.23%) compared to 11 of 4599 cancer-free women (0.24%) (OR = 0.96; 95% CI 0.48–1.93). The mutation frequency in 1988 women with familial breast cancer was 0.2% (OR = 0.84, 95% CI 0.27–2.65). Breast cancers in XRCC2 mutation carriers and non-carriers were similar with respect to age of diagnosis and clinical characteristics. Loss of the wild-type XRCC2 allele was observed only in one of the eight breast cancers from patients who carried the XRCC2 mutation. No cancer type was more common in first- or second-degree relatives of XRCC2 mutation carriers than in relatives of the non-carriers.

Conclusion

XRCC2 c.96delT is a protein-truncating founder variant in Poland. There is no evidence that this mutation predisposes to breast cancer (and other cancers). It is premature to consider XRCC2 as a breast cancer-predisposing gene.

Blood arsenic levels and the risk of familial breast cancer in Poland

Arsenic is recognized as a potent carcinogen at high concentrations, but the relationship between environmental arsenic and breast cancer risk has not well been studied. Most research has focused on the effect of arsenic in populations with high endemic exposure, and not in populations with arsenic levels within normal limits. We sought to determine if blood arsenic levels predict the risk of breast and other cancers risk among women in northern Poland. The cohort consisted of 1,702 healthy women, aged 40 and above, identified between 2010 and 2017. Blood arsenic level was determined by inductively coupled plasma mass spectrometry. After an average of 4.5 years of follow‐up (range 0.7–7.3 years), there were 110 incident cases of cancer diagnosed in the cohort, including 68 cases of breast cancer. Women in the highest quartile of arsenic had a highly significant 13‐fold increased risk of developing breast cancer, compared to women in the lowest quartile (hazard ratio [HR] = 13.2; 95% confidence interval [CI] 4.02–43.0). Results were similar for arsenic and all incident cancers (HR quartile 4 vs. quartile 1 = 13.3; 95% CI 4.78–37.0). If confirmed, our study suggests that the blood arsenic level may be a useful predictive marker of cancer risk in women.

What's new?

Arsenic has long been recognized as a potent carcinogen at high concentrations. But can it affect cancer risk at “normal,” environmental concentrations? In this Polish study, the authors found that women whose blood levels of arsenic were in the highest quartile had a 13‐fold increased risk of developing breast cancer, compared to women in the lowest quartile. If confirmed in further studies, these results suggests that blood arsenic level may be a useful predictive marker of cancer risk in women.

Allelic modification of breast cancer risk in women with an NBN mutation

BACKGROUND

NBN 657del5 founder mutation predisposes to breast and prostate cancer. Recently, it has been reported that the pathogenicity of this mutation with regard to prostate cancer risk is modified by a missense variant of the same gene (E185Q).

METHODS

To evaluate the interaction of the 657del5 and E185Q founder alleles of NBN on breast cancer risk in Poland, 4964 women with breast cancer and 6152 controls were genotyped for these two recurrent variants of NBN (657del5 truncating variant and E185Q missense variant).

RESULTS

The NBN 657del5 mutation was detected in 57 of 4964 unselected cases and in 35 of 6152 controls (OR = 2.0, p = 0.001). The E185Q GG genotype was detected in 2167 of 4964 unselected cases and in 2617 of 6152 controls (OR = 1.04, p = 0.3). In carriers of the 657del5 deletion, the elevated cancer risk was restricted to women with the GG genotype of the E185Q variant (OR = 3.6, 95% CI 1.9-6.6; p < 0.0001). Among women with other E185Q genotypes, the OR associated with 657del5 was 1.0 (95% CI 0.5-1.8; p = 0.9). The interaction between the two alleles was statistically significant (homogeneity p = 0.003).

CONCLUSION

In Poland, the pathogenicity of the NBN 657del5 mutation is restricted to women with a homozygous GG genotype of missense variant of the same gene (E185Q). This is the first clear example whereby a moderate penetrance breast cancer gene is impacted by a genetic modifier.

Changes in Bone Mineral Density After Prophylactic Bilateral Salpingo-Oophorectomy in Carriers of a BRCA Mutation

IMPORTANCE

Preventive surgery is strongly recommended for individuals with a BRCA mutation at a young age to prevent ovarian cancer and improve overall survival. The overall effect of early surgical menopause on various health outcomes, including bone health, has not been clearly elucidated.

OBJECTIVE

To evaluate the association of prophylactic bilateral salpingo-oophorectomy with bone mineral density (BMD) loss among individuals with a BRCA mutation.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study of participants with a BRCA mutation who underwent oophorectomy through the University Health Network, Toronto, Ontario, Canada, recruited participants from January 2000 to May 2013. Eligibility criteria included having a BRCA mutation, at least 1 ovary intact prior to surgery, and no history of any cancer other than breast cancer. Bone mineral density was measured using dual-energy x-ray absorptiometry before and after surgery. Data analysis began in December 2018 and finished in January 2019.

MAIN OUTCOMES AND MEASURES

The annual change in BMD from baseline to follow-up was calculated for the following 3 anatomical locations: (1) lumbar spine, (2) femoral neck, and (3) total hip.

RESULTS

A total of 95 women had both a baseline and postsurgery BMD measurement with a mean (SD) follow-up period of 22.0 (12.7) months. The mean (SD) age at oophorectomy was 48.0 (7.4) years. Among women who were premenopausal at time of surgery (50 [53%]), there was a decrease in BMD from baseline to follow-up across the lumbar spine (annual change, -3.45%; 95% CI, -4.61% to -2.29%), femoral neck (annual change, -2.85%; 95% CI, -3.79% to -1.91%), and total hip (annual change, -2.24%; 95% CI, -3.11% to -1.38%). Self-reported hormone therapy use was associated with significantly less bone loss at the lumbar spine (-2.00% vs -4.69%; P = .02) and total hip (-1.38% vs -3.21; P = .04) compared with no hormone therapy use. Among postmenopausal women at time of surgery (45 [47%]), there was also a significant decrease in BMD across the lumbar spine (annual change, -0.82%; 95% CI, -1.42% to -0.23%) and femoral neck (annual change, -0.68%; 95% CI, -1.33% to -0.04%) but not total hip (annual change, -0.18%; 95% CI, -0.82% to 0.46%).

CONCLUSIONS AND RELEVANCE

This study found that oophorectomy was associated with postoperative bone loss, especially among women who were premenopausal at the time of surgery. Targeted management strategies should include routine BMD assessment and hormone therapy use to improve management of bone health in this population.