Validating risk prediction models for multiple primaries and competing cancer outcomes in families with Li-Fraumeni syndrome using clinically ascertained data at a single institute

Purpose

There exists a barrier between developing and disseminating risk prediction models in clinical settings. We hypothesize this barrier may be lifted by demonstrating the utility of these models using incomplete data that are collected in real clinical sessions, as compared to the commonly used research cohorts that are meticulously collected.

Patients and methods

Genetic counselors (GCs) collect family history when patients (i.e., probands) come to MD Anderson Cancer Center for risk assessment of Li-Fraumeni syndrome, a genetic disorder characterized by deleterious germline mutations in the TP53 gene. Our clinical counseling-based (CCB) cohort consists of 3,297 individuals across 124 families (522 cases of single primary cancer and 125 cases of multiple primary cancers). We applied our software suite LFSPRO to make risk predictions and assessed performance in discrimination using area under the curve (AUC), and in calibration using observed/expected (O/E) ratio.

Results

For prediction of deleterious TP53 mutations, we achieved an AUC of 0.81 (95% CI, 0.70 - 0.91) and an O/E ratio of 0.96 (95% CI, 0.70 - 1.21). Using the LFSPRO.MPC model to predict the onset of the second cancer, we obtained an AUC of 0.70 (95% CI, 0.58 - 0.82). Using the LFSPRO.CS model to predict the onset of different cancer types as the first primary, we achieved AUCs between 0.70 and 0.83 for sarcoma, breast cancer, or other cancers combined.

Conclusion

We describe a study that fills in the critical gap in knowledge for the utility of risk prediction models. Using a CCB cohort, our previously validated models have demonstrated good performance and outperformed the standard clinical criteria. Our study suggests better risk counseling may be achieved by GCs using these already-developed mathematical models.

Other Primary Malignancies in Patients with Breast Cancer Who Undergo Germline Panel Testing

BACKGROUND

Women with a history of breast cancer (BC) more commonly have a diagnosis of other primary malignancies (OPMs) than the general population. This study sought to evaluate OPMs among patients with BC who underwent germline testing with a hereditary BC gene panel.

METHODS

The study identified women 18 years of age or older with a history of unilateral BC who underwent multi-gene panel testing between January 2014 and August 2019 at the authors' institution. Patient, tumor, and treatment factors for BC and OPM diagnoses were collected for descriptive, univariate, and overall survival (OS) analyses.

RESULTS

Among 1163 patients, 330 (28.4%) had an OPM. The median follow-up period was 4.1 years from BC diagnosis. Of the 1163 patients, 209 (18%) had a BRCA pathogenic variant (PV), 306 (26.4%) had a non-BRCA PV, and 648 (55.7%) had no PV. Development of an OPM varied according to germline testing result, with an OPM developing for 18.6% (39/209) of the patients with a BRCA PV, 31.8% (204/648) of the patients with no PV, and 28.4% (87/306) of the patients with a non-BRCA PV (p < 0.0001). The most common OPMs were ovarian (n = 60), uterine (n = 44), sarcoma (n = 36), melanoma (n = 27), colorectal (n = 22), and lymphoma (n = 20) malignancies. The 5-year OS was 96%. The patients with an OPM 5 years after BC diagnosis had a shorter OS than those who did not (93.4% vs 97.5%; p = 0.002).

CONCLUSION

More than 25% of women with BC who underwent germline panel testing had an OPM diagnosed during the short-term follow-up period, and the diagnosis of an OPM was associated with reduced OS. These data have implications for counseling BC patients who undergo germline testing regarding future cancer screening.

Clinical outcomes and Oncotype DX Breast Recurrence Score® in early-stage BRCA-associated hormone receptor-positive breast cancer

Background

BRCA‐associated breast cancers tend to have distinctive features compared to sporadic breast cancers; further characterization can aid in optimizing treatment.

Methods

The study evaluated a patient cohort with early‐stage estrogen receptor positive, HER2 negative invasive breast cancer who had Oncotype DX Breast Recurrence Score® analysis and genetic testing for hereditary breast and ovarian cancer syndrome. Data on patients and their breast cancers with outcomes were collected and analyzed.

Results

745 patients were included, of whom 33 had pathogenic BRCA mutations (8 BRCA1, 25 BRCA2). Patients with BRCA mutations were younger and received more adjuvant chemotherapy, but less endocrine therapy and radiation therapy. BRCA‐associated breast cancers had less progesterone receptor expression, higher nuclear grade, and higher Oncotype DX Breast Recurrence Scores® with median Recurrence Score® 29, compared to 16 in cancers without mutations (p < 0.0001). Breast cancer recurrence developed in 18% of patients with BRCA mutations and 9% of patient without mutations, although multivariate analysis of relapse‐free survival was not significant, HR 1.519 (95% confidence interval [CI] 0.64–3.58; p = 0.3401). After adjusting for Recurrence Score®, overall survival by BRCA status was improved HR 0.448 (95% CI 0.06–3.34; p = 0.4333).

Conclusions

BRCA‐associated early‐stage hormone receptor‐positive breast cancers have higher Oncotype DX Breast Recurrence Score® compared to those without mutations. BRCA status did not significantly impact relapse‐free survival and overall survival. Larger clinical trials are needed to further assess the findings, and if confirmed, could impact clinical management of BRCA‐associated breast cancers.

Outcomes After Breast Radiation Therapy in a Diverse Patient Cohort With a Germline BRCA1/2 Mutation

PURPOSE

BRCA1/2 pathogenic variant (PV) mutations confer radiation sensitivity preclinically, but there are limited data regarding breast cancer outcomes after radiation therapy (RT) among patients with documented BRCA1/2 PV mutations versus no PV mutations.

METHODS AND MATERIALS

This retrospective cohort study included women with clinical stage I-III breast cancer who received definitive surgery and RT and underwent BRCA1/2 genetic evaluation at the The University of Texas MD Anderson Cancer Center. Rates of locoregional recurrence (LRR), disease-specific death (DSD), toxicities, and second cancers were compared by BRCA1/2 PV status.

RESULTS

Of the 2213 women who underwent BRCA1/2 testing, 63% self-reported their race as White, 13.6% as Black/African American, 17.6% as Hispanic, and 5.8% as Asian/American Indian/Alaska Native; 124 had BRCA1 and 100 had BRCA2 mutations; and 1394 (63%) received regional nodal RT. The median follow-up time for all patients was 7.4 years (95% confidence interval [CI], 7.1-7.7 years). No differences were found between the groups with and without BRCA1/2 PV mutations in 10-year cumulative incidences of LRR (with mutations: 11.6% [95% CI, 7.0%-17.6%]; without mutations: 6.6% [95% CI, 5.3%-8.0%]; P = .466) and DSD (with mutations: 12.3% [95% CI, 8.0%-17.7%]; without mutations: 13.8% [95% CI, 12.0%-15.8%]; P = .716). On multivariable analysis, BRCA1/2 status was not associated with LRR or DSD, but Black/African American patients (P = .036) and Asians/American Indians/Alaska Native patients (P = .002) were at higher risk of LRR compared with White patients, and Black/African American patients were at higher risk of DSD versus White patients (P = .004). No in-field, nonbreast second cancers were observed in the BRCA1/2 PV group. Rates of acute and late grade ≥3 radiation-related toxicity in the BCRA1/2 PV group were 5.4% (n = 12) and 0.4% (n = 1), respectively.

CONCLUSIONS

Oncologic outcomes in a diverse cohort of patients with breast cancer who had a germline BRCA1/2 PV mutation and were treated with RT were similar to those of patients with no mutation, supporting the use of RT according to standard indications in patients with a germline BRCA1/2 PV mutation.

Breast Radiation Therapy-Related Treatment Outcomes in Patients With or Without Germline Mutations on Multigene Panel Testing

PURPOSE

Multigene panel testing has increased the detection of germline mutations in patients with breast cancer. The implications of using radiation therapy (RT) to treat patients with pathogenic variant (PV) mutations are not well understood and have been studied mostly in women with only BRCA1 or BRCA2 PVs. We analyzed oncologic outcomes and toxicity after adjuvant RT in a contemporary, diverse cohort of patients with breast cancer who underwent genetic panel testing.

METHODS AND MATERIALS

We retrospectively reviewed the records of 286 women with clinical stage I-III breast cancer diagnosed from 1995 to 2017 who underwent surgery, breast or chest wall RT with or without regional nodal irradiation, multigene panel testing, and evaluation at a large cancer center's genetic screening program. We evaluated rates of overall survival, locoregional recurrence, disease-specific death, and radiation-related toxicities in 3 groups: BRCA1/2 PV carriers, non-BRCA1/2 PV carriers, and patients without PV mutations.

RESULTS

PVs were detected in 25.2% of the cohort (12.6% BRCA1/2 and 12.6% non-BRCA1/2). The most commonly detected non-BRCA1/2 mutated genes were ATM, CHEK2, PALB2, CDH1, TP53, and PTEN. The median follow-up time for the entire cohort was 4.4 years (95% confidence interval, 3.8-4.9 years). No differences were found in overall survival, locoregional recurrence, or disease-specific death between groups (P > .1 for all). Acute and late toxicities were comparable across groups.

CONCLUSION

Oncologic and toxicity outcomes after RT in women with PV germline mutations detected by multigene pane testing are similar to those in patients without detectable mutations, supporting the use of adjuvant RT as a standard of care when indicated.

Cytoplasmic Cyclin E Expression Predicts for Response to Neoadjuvant Chemotherapy in Breast Cancer

BACKGROUND

Pathologic complete response (pCR) has been shown to be associated with favorable outcomes in breast cancer. Predictors of pCR could be useful in guiding treatment decisions regarding neoadjuvant therapy. The objective of this study was to evaluate cyclin E as a predictor of response to neoadjuvant chemotherapy in breast cancer.

METHODS

Patients (n = 285) with stage II-III breast cancer were enrolled in a prospective study and received neoadjuvant chemotherapy with anthracyclines, taxanes, or combination of the two. Pretreatment biopsies from 190 patients and surgical specimens following chemotherapy from 192 patients were available for immunohistochemical analysis. Clinical and pathologic responses were recorded and associated with presence of tumor infiltrating lymphocytes, cyclin E, adipophilin, programmed cell death-ligand 1, and elastase staining and other patient, tumor and treatment characteristics.

RESULTS

The pCR rate was significantly lower in patients with cytoplasmic cyclin E staining compared with those who had no cyclin E expression (16.1% vs 38.9%, P = 0.0005). In multivariable logistic regression analysis, the odds of pCR for patients who had cytoplasmic negative tumors was 9.35 times (P value < 0.0001) that compared with patients with cytoplasmic positive tumors after adjusting for ER, PR, and HER2 status. Cytoplasmic cyclin E expression also predicts long-term outcome and is associated with reduced disease free, recurrence free, and overall survival rates, independent of increased pretreatment tumor infiltrating lymphocytes.

CONCLUSIONS

Cyclin E independently predicted response to neoadjuvant chemotherapy. Hence, its routine immunohistochemical analysis could be used clinically to identify those breast cancer patients expected to have a poor response to anthracycline/taxane-based chemotherapy.

Abstract PS8-04: Clinical and pathological characteristics and screening outcome for secondary cancers in breast cancer patients with li-fraumeni syndrome attending the MD anderson li-fraumeni education and early detection program clinic

Background: Germline TP53 mutations predispose to early onset breast cancer (BC) and are associated with Li-Fraumeni syndrome (LFS) Published data on the clinical and pathological characteristics and screening outcome for secondary cancers among women with BC and TP53 mutations is limited. The UTMD Anderson's Li-Fraumeni Education and Early Detection (LEAD) program conducts comprehensive cancer screening for patients with LFS. Here we report characteristics and screening outcome of patients with BC and LFS who were referred to the LEAD program.

Methods: Patients with BC and LFS were identified from a prospective BC database between 2001 to 2018. Patients had genetic testing at The University of Texas MD Anderson Cancer Center (MDACC) Clinical Cancer Genetics (CCG) program and confirmed to have germline TP53 mutations. Data reviewed included clinical and pathological characteristics of their BC, the pattern of referral to the LEAD program, adherence to screening recommendation and rate of secondary cancer detection in the LEAD program.

Results: A total of 78 female patients with positive germline TP53 mutation and BC diagnosis were identified. The clinical and pathological characteristics of these patients are provided in table 1. Out of the 78 patients, 62 patients were referred and followed at the LEAD clinic. 50 were referred after BC diagnosis and 12 were referred to LEAD clinic before BC diagnosis. A total of 137 cancers were diagnosed in the total population. The cancers were further grouped into diagnosed before or after BC diagnosis. (table 2). 24 cancers were diagnosed in LEAD clinic including 12 breast cancers, 2 soft tissue tumors, 2 thyroid cancers, 2 acute myeloid leukemia, 1 brain tumor, 1 lung cancer, 1 pancreatic cancer, 1 melanoma, 1 parotid cancer and 1 Merkel cell cancer. Adherence to follow up and recommended screening in the first year was 77%, second year 75% and third year 65%. 6 patients, who were diagnosed with leukemia, had received adjuvant chemotherapy with anthracycline and/or cyclophosphamide-based therapy for breast cancer with median time from chemotherapy to leukemia diagnosis of 9 years (5-10yrs). 8 patients developed chest wall sarcoma in the same location of prior radiation therapy for breast cancer with median time from radiation therapy to chest wall sarcoma diagnosis of 7 years (3-11yrs).

Conclusion: Patients with LFS associated breast cancer are at significant increased risk to develop secondary cancers. Increased surveillance for secondary cancers in a dedicated program can increase adherence to screening, lead to early detection that could potentially lead to improved outcomes. Patient outcome of this cohort will be presented at the meeting.

Table 1: Clinical and Pathological Characteristics of Women with Breast cancer and LFSN(%)N(%)Median Age (Range)33 (20, 63)——Hormonal receptor/HER-2 status+/+22(31.4%)RaceAsian/Pacific islander7(9%)+/-27(38.6%)Black8(10.3%)-/+14(20%)Hispanic12(15.4%)-/-7(10%)White51(65.4%)Menopausal status at the time of BC diagnosis.Pre-menopausal(72%)Stage013(16.9%)Post-menopausal(28%)I21(27.3%)HistologyDCIS12(15.6%)II31(40.3%)IDC49(63.6%)III9(11.7%)ILC3(3.9%)IV3(3.9%)LCIS1(1.3%)Breast cancer diagnosisMRI4(5.2%)Mixed8(10.4%)Palpated lesion51(66.2%)Mucinous2(2.6%)Screening mammogram22(28.6%)Phyllodes2(2.6%)

Table 2: Cancer diagnosed in the total population N=78 grouped into before and after to BC diagnosisCancer diagnosed before BC diagnosisNCancer diagnosed after BC diagnosisNSoft tissue sarcoma13Soft tissue sarcoma18CNS1Lung2Thyroid3Thyroid3leukemia2Merkel cell1Adrenal2Leukemia6Uterus1CNS3Renal1pancreas1Melanoma1Parotid1

Citation Format: Aydah Al-Awadhi, Nour Abuhadra, Diane D Liu, Angelica M Gutierrez Barrera, Jessica Corredor, Louise C Strong, Banu K Arun. Clinical and pathological characteristics and screening outcome for secondary cancers in breast cancer patients with li-fraumeni syndrome attending the MD anderson li-fraumeni education and early detection program clinic [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 PS8-04.

Clinical outcome and toxicity from taxanes in breast cancer patients with BRCA1 and BRCA2 pathogenic germline mutations

Germline variations in genes coding for proteins involved in the oxidative stress and DNA repair greatly influence drug response and toxicity. Because BRCA1 and BRCA2 proteins play a role in DNA damage repair, we postulated that taxane-related toxicity is potentially higher and clinical outcome in different in patients with BRCA pathogenic variants (PV). Seven hundred nineteen women who underwent BRCA genetic testing and were treated with taxane-containing chemotherapy for early-stage breast cancer between 1997 and 2018 were included in the study. Patients with BRCA variants of uncertain significance were excluded. The Kaplan-Meier product-limit method was used to estimate recurrence-free survival (RFS) and overall survival (OS) rates. Logistic regression models were used to assess the association between chemotherapy toxicity and factors of interest. Cox regression models were used to assess the association between RFS and OS and factors of interest. Ninety-four (13%) and 54 (7%) patients had BRCA1 and BRCA2-PVs, respectively. While anemia (P = .0025) and leukopenia (P = .001) were more frequently seen in BRCA noncarriers, there was no difference in regards to peripheral neuropathy or other toxicities between the groups. Increasing doses of taxane were associated with increased risk of neutropenia, stomatitis, nausea, vomiting, acne/rash, and peripheral neuropathy across all groups. In a multivariate logistic regression model, BRCA2 status remained as an independent significant predictor for decreased hematologic toxicity (HR: 0.36; 95% CI: 0.20-0.67; P = .001) and increased gastrointestinal toxicity (HR: 1.93; 95% CI: 1.02-3.67; P = .04). Being overweight, obese and African-American race were significant predictors for peripheral neuropathy (P = .04; P = .03; P = .06, respectively). Total taxane dose received did not have any impact on survival outcomes. Our study demonstrates that taxane-containing chemotherapy regimens do not increase risk of peripheral neuropathy or hematologic toxicity in patients with BRCA PVs. The mechanisms for this finding need to be further investigated as it may provide an opportunity to combine taxanes with other agents, such as platinum salts or PARP inhibitors, with less anticipated toxicity.

Contralateral Risk-Reducing Mastectomy in Breast Cancer Patients Who Undergo Multigene Panel Testing

BACKGROUND

An increasing number of breast cancer patients are undergoing expanded genetic testing and are being identified as germline mutation carriers. We sought to determine rates of contralateral risk-reducing mastectomy (CRRM) in patients with various germline mutations.

PATIENTS AND METHODS

All women ≥ 18 years of age with unilateral breast cancer who underwent multigene panel testing between January 1, 2014 and August 1, 2019 at our academic institution were identified. Demographic, tumor, and treatment variables were identified from the medical record. Multivariable analyses were performed to compare factors associated with performance of CRRM.

RESULTS

We identified 1613 patients, of whom 28.1% had a pathogenic variant and 40.1% had variants of uncertain significance (VUS). Overall, 420 patients (26.0%) underwent a CRRM. On multivariable analysis, factors associated with CRRM included age < 50 years (OR 3.8, 95% CI 3.0, 5.0), race (OR 0.5, 95% CI 0.3, 0.7 and OR 0.4, 95% CI 0.2, 0.7 for Black and Asian women, respectively, versus White women), and the presence of any germline mutation or VUS (OR 13.2, 95% CI 8.7, 20.2 for BRCA1/2; OR 3.9, 95% CI 2.7, 5.8 for non-BRCA germline mutation; and OR 1.8, 95% CI 1.3, 2.6 for VUS).

CONCLUSIONS

In breast cancer patients who undergo multigene panel testing, a sizeable number of women with pathogenic non-BRCA germline findings are opting for CRRM. Given that the risk of contralateral breast cancer in women with most pathogenic mutations other than BRCA1/2 remains poorly characterized, these data have implications for risk counseling and for ascertaining the true risks of contralateral breast cancer in this population.

Abstract P6-08-06: Characteristics of ductal carcinoma in situ (DCIS) in patients who underwent multigene panel testing for hereditary breast cancer

Background: Multigene panel testing (MPG) for hereditary breast cancer has recently increased significantly. While clinical and pathological characteristics for invasive breast cancer in patients with non BRCA germline mutations is emerging, there is very limited data in patients with ductal carcinoma in situ (DCIS). This study evaluates the clinical and pathological characteristics of patients with DCIS who underwent MPG testing for hereditary breast cancer.

Methods: Patients with DCIS who underwent MPG testing between 2014-2019 were identified from our prospectively maintained and IRB-approved research registry study and included in this analysis. Clinical and tumor characteristics were analyzed using descriptive statistics. Variables included in the analysis included: Age at diagnosis, family history of breast and ovarian cancer, tumor characteristics including ER/PR and nuclear grade and genetic testing results.

Results: In this prospective cohort, 324 patients with DCIS underwent multigene panel testing. Age of diagnosis was 50.5 years (range: 18-86), a family history of breast and/or ovarian cancer was positive in 283 (87.3%) patients. Genetic testing results were as follows: Pathogenic or likely pathogenic mutations were found in 28 (8.6%) patients: BRCA1 2 (7.1%), BRCA2 6 (21.4%), PALB2 6 (21.4%), CHEK2 5 (17.9%), ATM 3 (10.7%), APC 2 (7.1%), BARD1 1 (3.6%), BRIP1 1 (3.6%), MSH2 1 (3.6%), MUTYH 1 (3.6%). The variant of uncertain significance rate was 16% (52): 7 (13.5%) in BRCA1 or 2 and 45 (86.5%) in other genes. 244 (75.3%) of patients had negative results.

Conclusion: Our data demonstrates that, in addition to BRCA 1 and 2 genes, patients with DCIS have other hereditary genes involved. In fact, 71.4% of the germline mutations were in non-BRCA genes. Regardless of gene status, most patients had ER positive disease, this can have implications for chemopreventive therapy. Furthermore, patients with germline mutations have a higher percentage of nuclear grade III DCIS than gene negative patients. Larger studies are needed to evaluate the clinical implications of these findings. Genetic testing with a larger panel, other than BRCA1 and BRCA2 genes only, should be considered for patients with DCIS.

NegativeBRCA1+BRCA2+PALB2+CHEK2+ATM+Variablesn%n%n%n%n%n%ERpositive17471.32100.0583.3350.0480.03100.0negative187.400.000.0116.7120.000.0unknown5120.900.0116.7233.300.000.0PRpositive15262.3150.0583.3350.0480.03100.0negative3815.6150.000.0116.7120.000.0unknown5422.100.0116.7233.300.000.0NGI187.4150.000.000.0240.000.0II10041.000.0116.7350.0240.0133.3III8534.8150.0466.7233.300.0266.7unknown4116.800.0116.7116.7120.000.0Totals244100.02100.06100.06100.05100.03100.0

Citation Format: Loredana Militello, Angelica M Gutierrez Barrera, Henry Kuerer, Constance Albarracin, Banu K Arun. Characteristics of ductal carcinoma in situ (DCIS) in patients who underwent multigene panel testing for hereditary breast cancer [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 P6-08-06.

Abstract P6-08-26: Clinical characteristics of breast cancer patients with ATM mutations

Background: Pathogenic ATM gene mutations are associated with increased risk of developing several cancers such as lymphoid, gastric, breast, central nervous system, skin, and other cancers. The relative risk of breast cancer is 2.3, with a higher risk seen for women under the age of 50 years. Only few and small studies have reported on the characteristics of breast cancers in women with ATM mutations. Here, we aimed to describe the clinical and pathological characteristics of a single institution largest cohort, to the best of our knowledge, of breast cancer patients with ATM mutations.

Methods: Patients with breast cancer who presented to the University of Texas MD Anderson Cancer Center Clinical Cancer Genetics clinics and underwent genetic testing for hereditary breast cancer and were found to have an ATM mutation were included. A retrospective review of a prospectively maintained research database was performed for ATM mutation status as well as patient clinical and pathological characteristics. IRB approval was granted for this analysis.

Results: Between 2012 and 2019, a total of 4093 breast cancer patients underwent genetic testing for hereditary breast cancer that included ATM gene testing. The median age of diagnosis of breast cancer was 49.3 (17-89), and median age at genetic testing was 52.1 (18-86). 72% of patients had stage 0-III and 3.2% stage 4 disease. Among patients with ATM pathogenic mutations, 37.7% (10) versus 21.7% (843) of ATM negative patients had a history of multiple primaries of any cancers. The table below shows characteristics of ATM pathogenic mutation carriers versus ATM negative patients.

Conclusion: This is a single institution cohort of breast cancer patients with ATM mutations that show distinct clinical characteristics, such as multiple primary cancers. These findings could have therapeutic implications and should be confirmed in larger cohorts.

Pathogenic Mutation of ATM ATM NegativesVariablesn%n%ERPositive4075.5221757.1Negative11.976019.6Unknown1222.690423.3PRPositive3667.9188448.5Negative59.4107027.6Pos/Neg00.010.03Unknown1222.692623.9Her2Positive1018.958611.3Negative2241.5206257.0Unknown2139.6123314.2Stage059.43178.2I1324.597825.2II1120.8106527.4III713.243611.2IV47.51243.2Unknown1324.596124.8Nuclear GradeI23.82596.7II1935.8111228.7III1120.8115629.8Unknown2139.6135434.9Triple Negative?Yes00.053913.9No3769.8222757.4Unknown1630.2111528.7

Citation Format: Loredana Militello, Angelica M Gutierrez Barrera, Constance Albarracin, Isabelle Bedrosian, Banu K Arun. Clinical characteristics of breast cancer patients with ATM mutations [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 P6-08-26.

Abstract P2-09-04: Reclassification of variant of unknown significance in BRCA1 and BRCA2 genes based on loss of heterozigosity assay

Variants of unknown significance (VUS) occur in approximately 10% of BRCA1 and BRCA2 genetic testing. Definition of VUS as pathogenic or of benign potential is a crucial step in the reporting and counseling process. Thus limiting the clinical utility of a genetic test and impairs the correct patient management. BRCA1 and 2 are tumor suppressor genes and loss of heterozygosity (LoH) as a second hit for inactivating wildtype allele is a relatively common event in tumor. Previously, in a multi-institutional effort, AC Camargo Cancer Center (Brazil), Barretos Cancer Hospital (Brazil) and UTMD Anderson Cancer Center (USA) compiled a total of 332 BRCA1/2 VUS supposedly from unrelated carriers (46 of BRCA1 and 286 of BRCA2). From them, 256 were distinct VUS (37 in BRCA1 and 219 in BRCA2). Breast cancer sub-classification were collected from medical records and in silico analyzes were performed using four software (SIFT, Polyphen2, CADD and REVEL). Based on this analysis, VUS were categorized into five classes: very high, high, medium, low and very low risk of pathogenicity, according to agreement level among the four in silico software. However, all these analysis are not sufficient for supporting the reclassification of VUS. Therefore we proposed to analyze LoH in matched tumor tissue to assess the pathogenic potential of BRCA1 and 2 VUS. Normal (leucocytes or normal breast tumor tissue) samples, when available, were used for correcting PCR amplification bias between the two alleles. DNA was extracted and subjected to PCR reaction. Amplicons libraries were performed according to manufacturing protocol (Ion Plus Fragment Library Kit) and sequenced on the Ion Proton™ System (ThermoFisher Scientific). Specific variants were called in the TVC program (ThermoFisher Scientific) with standard criteria. A total of 12 VUS were investigated (5 in BRCA1 and 7 in BRCA2). LoH was detected in 7 (60%) tumor samples (3 in BRCA1 and 4 in BRCA2). Of these, 4 VUS were classified as very high or high risk of pathogenicity [2 in BRCA1 (BR1p.Y1703C; BR1p.S1655P) and 2 in BRCA2 (BR2p.S2670L; BR2p.E3002K)]. Variant of allele frequency (VAF) of 94, 65, 70 and 75%, respectively, were detected in tumor tissues. Additionally, recent functional assays described these 4 VUS as non-functional or deleterious variants showing complete agreement with the current LoH results. According to ACMG guidelines considering all available data, LoH, deleterious function and concordant pathogenicity probability. These 4 VUS might be reclassified as pathogenic variants. On the other hand, the same combined analysis did not allow reclassification of 3 other VUS. Although VAF were 74, 73 and 70% respectively, they were previously classified as very or low risk of pathogenicity and there are no functional assays describing them until now. Our results showed that LoH analyses can substantially contribute to VUS reclassification, improving the management and counseling of BRCA1/2 VUS-carriers.

Citation Format: Dirce M Carraro, Edenir I Palmero, Carolina M Berra, Giovana T Torrezan, Rafael C Brianese, Gabriela C Fernandes, Angelica M Gutierrez Barrera, Henrique C Galvo, Maria NC Formiga, Banu K Arun. Reclassification of variant of unknown significance in BRCA1 and BRCA2 genes based on loss of heterozigosity assay [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 P2-09-04.

Prospective Evaluation of Universal BRCA Testing for Women With Triple-Negative Breast Cancer

Background

Limited published literature exists on women with triple-negative breast cancer (TNBC) diagnosed over the age of 60 years with breast cancer gene (BRCA) pathogenic variants. Our study determined whether the rate of BRCA pathogenic variants in a prospective cohort of TNBC patients outside the definition of current clinical genetic testing (GT) guidelines warrants a change in recommendations.

Methods

A prospective study of 395 women with TNBC underwent genetic counseling and 380 (96.2%) underwent clinical BRCA GT regardless of age of diagnosis beginning January 2014 to October 2015 at The University of Texas MD Anderson Cancer Center, Houston. TNBC patients older than 60 years who did not meet clinical GT guidelines had comprehensive sequencing and large rearrangement GT as part of the research protocol.

Results

Fifty-one of 380 (13.4%) women with TNBC who underwent clinical BRCA GT were BRCA positive. Of the 86 patients diagnosed at age over 60 years and underwent GT, only two (2.3%) were positive for BRCA. These two patients would have met clinical testing criteria due to family or ancestral history.

Conclusions

Our study does not support universal BRCA testing for TNBC patients diagnosed older than 60 years as their only risk factor for a BRCA pathogenic variant. Both of the positive BRCA patients older than 60 years identified would have met current National Comprehensive Cancer Network criteria for testing. Therefore, our study demonstrates that the National Comprehensive Cancer Network guidelines provide sufficient criteria for identifying BRCA pathogenic variants in women with TNBC at 60 years or younger.

Elevated serum levels of sialyl Lewis X (sLeX) and inflammatory mediators in patients with breast cancer

PURPOSE

The carbohydrate sialyl Lewis^X (sLe^X) mediates cell adhesion, is critical in the normal function of immune cells, and is frequently over-expressed on cancer cells. We assessed the association, differential levels, and prognostic value of sLe^X and inflammatory cytokines/chemokines in breast cancer sera.

METHODS

We retrospectively measured sLe^X and a panel of cytokines/chemokines in the sera of 26 non-invasive ductal carcinoma in situ (DCIS), 154 invasive non-metastatic breast cancer (non-MBC), 63 metastatic breast cancer (MBC) patients, and 43 healthy controls. Differences in sLe^X and inflammatory cytokines among and between patient groups and healthy controls were assessed with nonparametric tests and we performed survival analysis for the prognostic potential of sLe^X using a cut-off of 8 U/mL as previously defined.

RESULTS

Median serum sLe^X was significantly higher than controls for invasive breast cancer patients (MBC and non-MBC) but not DCIS. In univariate analysis, we confirmed patients with serum sLe^X > 8 U/mL have a significantly shorter progression-free survival (PFS) (P = 0.0074) and overall survival (OS (P = 0.0003). Similarly, patients with high serum MCP-1 and IP-10 had shorter OS (P = 0.001 and P < 0.001, respectively) and PFS (P = 0.010 and P < 0.001, respectively). sLe^X, MCP-1 and IP-10 remained significant in multivariate survival analysis.

CONCLUSION

Elevated serum sLe^X was associated with invasive cancer but not DCIS. High serum sLe^X levels were associated with inflammatory mediators and may play a role in facilitating local invasion of breast tumor. Furthermore, serum MCP-1, IP-10 and sLe^X may have prognostic value in breast cancer.

Contralateral prophylactic mastectomy rate and predictive factors among patients with breast cancer who underwent multigene panel testing for hereditary cancer

Although multigene panel testing is increasingly common in patients with cancer, the relationship between its use among breast cancer patients with non-BRCA mutations or variants of uncertain significance (VUS) and disease management decisions has not been well described. This study evaluated the rate and predictive factors of CPM patients who underwent multigene panel testing. Three hundred and fourteen patients with breast cancer who underwent multigene panel testing between 2014 and 2017 were included in the analysis. Of the 314 patients, 70 elected CPM. Election of CPM by gene status was as follows: BRCA carriers (42.3%), non-BRCA carriers (30.1%), and VUS (10.6%). CPM election rates did not differ between non-BRCA carriers and BRCA carriers (P = 0.6205). Among non-BRCA carriers, negative hormone receptor status was associated with CPM (P = 0.0115). For those with a VUS, hormone receptor status was not associated with CPM (P = 0.1879). Although the rate of CPM between BRCA carriers and non-BRCA carriers was not significantly different, the predictors of CPM were different in each group. Our analyses shed the light on the increasing use of CPM among patients who are non-BRCA carriers as well those with a VUS. Our study elucidates the differing predictive factors of CPM election among BRCA carriers, non-BRCA carries, and those with a VUS. Our findings reveal the need for providers to be cognizant that non-BRCA genes and VUS drive women to elect CPM despite the lack of data for contralateral breast cancer risk associated with these genes.

BRCA mutations in women with inflammatory breast cancer

BACKGROUND

Inflammatory breast cancer (IBC) often affects women at a relatively young age. To the authors' knowledge, the rate of BRCA variants among patients with IBC is not known. To determine the association between BRCA status and IBC, the authors evaluated its rate and compared the clinicopathologic characteristics of patients with IBC with those of patients with other breast cancers (non-IBC).

METHODS

Patients who presented at the study institution's cancer genetics program and who underwent BRCA genetic testing were included in the current study. The authors compared clinicopathologic data between patients with IBC and those with non-IBC using propensity score matching to identify predictors.

RESULTS

A total of 1789 patients who underwent BRCA genetic testing (1684 with non-IBC and 105 with IBC) were included. BRCA pathogenic variants were found in 27.3% of patients with non-IBC and 18.1% of patients with IBC (P = .0384). After propensity score matching, there were no significant differences noted between patients with IBC and those with non-IBC, including the rate of BRCA pathogenic variants (P = .5485). However, a subgroup analysis of the 479 patients with BRCA pathogenic variants demonstrated that patients with IBC (19 patients) were diagnosed at significantly younger ages compared with patients with non-IBC (P = .0244).

CONCLUSIONS

There was no clear association observed between BRCA pathogenic variants and IBC. However, among patients who tested positive for BRCA pathogenic variants, those with IBC were younger at the time of diagnosis compared with those with non-IBC breast cancers. These results confirm that genetic testing is important for patients with IBC who meet the current clinical criteria for genetic testing in breast cancer. Cancer 2018;124:466-74. © 2017 American Cancer Society.

Inflammatory breast cancer: a proposed conceptual shift in the UICC-AJCC TNM staging system

In the absence of histological criteria that distinguish between inflammatory and non-inflammatory breast cancer, diagnosis of inflammatory breast cancer relies entirely on the existence of clinical criteria as outlined by the TNM classification. This classification restricts patients presenting with clinical criteria characteristic of inflammatory breast cancer to subcategory T4d, which immediately relegates all patients with non-metastatic inflammatory breast cancer to stage 3, regardless of tumour size or nodal spread. Patients who present with metastatic disease are consigned to stage 4, and the TNM classification does not distinguish patients on the basis of the presence of inflammatory criteria. Evidence by our group and others suggests that patients with inflammatory breast cancer have significantly reduced overall survival among those who present with distant metastasis at diagnosis (stage 4). In light of these results, this Personal View addresses whether the current TNM staging classification accurately represents a distinction between patients with inflammatory and those with non-inflammatory breast cancer.

Evaluation of BRCAPRO Risk Assessment Model in Patients with Ductal Carcinoma In situ Who Underwent Clinical BRCA Genetic Testing

The authors retrospectively aimed to determine which of the following three scenarios, related to DCIS entry into BRCAPRO, predicted BRCA mutation status more accurately: (1) DCIS as an invasive breast cancer (IBC) entered using the actual age of diagnosis, (2) DCIS as IBC entered with 10 years added to the actual age of diagnosis, and (3) DCIS entered as no cancer. Of the 85 DCIS patients included in the study, 19% (n = 16) tested positive for a BRCA mutation, and 81% (n = 69) tested negative. DCIS patients who tested positive for a BRCA mutation had a higher BRCAPRO risk estimation (34.61%) than patients who tested negative (11.4%) when DCIS was entered at the actual age of diagnosis. When DCIS was entered with 10 years added to the actual age at diagnosis, the BRCAPRO estimate was still higher amongst BRCA positive patients (25.4%) than BRCA negative patients (7.1%). When DCIS was entered as no cancer, the BRCAPRO estimate remained higher among BRCA positive patients (2.56%) than BRCA negative patents (1.98%). In terms of accuracy of BRCA positivity, there was no statistically significant difference between DCIS at age at diagnosis, DCIS at 10 years later than age at diagnosis, and DCIS entered as no cancer (AUC = 0.77, 0.784, 0.75, respectively: p = 0.60). Our results indicate that regardless of entry approach into BRCAPRO, there were no significant differences in predicting BRCA mutation in patients with DCIS.

Predictors that Influence Election of Contralateral Prophylactic Mastectomy among Women with Ductal Carcinoma in Situ who are BRCA-Negative

The authors retrospectively examined the contralateral prophylactic mastectomy (CPM) rate among 100 women with ductal carcinoma in situ who are BRCA negative. Of 100 women with ductal carcinoma in situ, 31 elected contralateral prophylactic mastectomy (CPM). Factors associated with increased likelihood of undergoing contralateral prophylactic mastectomy (CPM) among this cohort were: family history of ovarian cancer, marital status, reconstruction, mastectomy of the affected breast, and tamoxifen use.

Predictors that influence contralateral prophylactic mastectomy election among women with ductal carcinoma in situ who were evaluated for BRCA genetic testing

BACKGROUND

Patients with ductal carcinoma in situ (DCIS) are at increased risk for developing contralateral breast cancer (CBC). Consequently, more women with DCIS are electing to undergo contralateral prophylactic mastectomy (CPM). We evaluated factors associated with CPM in patients with DCIS who underwent genetic counseling for BRCA testing.

METHODS

This retrospective study involved 165 women with DCIS referred for genetic counseling between 2003 and 2011. Patient characteristics were age, marital and educational status, tumor markers, nuclear grade, family history of breast cancer (BC) and ovarian cancer (OC), race, Ashkenazi Jewish ancestry, and BRCA results. Univariate and multivariate logistic regression analyses were used to determine predictive factors associated with CPM election.

RESULTS

Of 165 patients, 44 (27 %) underwent CPM. Patients <45 years of age were more likely to elect CPM (p = 0.0098). A BRCA+ mutation was found in 17 patients (10.3 %), and BRCA+ women were more likely to elect CPM than BRCA or untested women (p = 0.0001). Patients who had a family history of OC (57.7 %) were more likely to choose CPM than those with no family history (p = 0.0004). Younger age, BRCA+, and an OC family history remained significant in the multivariate model (p < 0.008).

CONCLUSION

The CPM rate among patients with DCIS who undergo genetic counseling is high. Factors associated with increased likelihood of CPM among this group were age, BRCA+, and a family history of OC. Further studies are needed to evaluate patients' perceptions of CBC risk and their role in the likelihood of CPM choice.

Response to neoadjuvant systemic therapy for breast cancer in BRCA mutation carriers and noncarriers: a single-institution experience

PURPOSE

To compare the pathologic complete response (pCR) rate and relapse-free survival (RFS) and overall survival (OS) after neoadjuvant systemic chemotherapy (NST) in patients with breast cancer with and without deleterious BRCA1 and BRCA2 mutations.

PATIENTS AND METHODS

A total of 317 women who underwent BRCA genetic testing and were treated with NST for breast cancer between 1997 and 2009 were included in the study. The Kaplan-Meier product-limit method was used to estimate RFS and OS rates. Logistic regression models were fit to determine the associations between BRCA status, pCR, and survival.

RESULTS

Fifty-seven (18%) and 23 (7%) patients had BRCA1 and BRCA2 mutations, respectively. Twenty-six (46%) of 57 BRCA1 carriers achieved a pCR, compared with three (13%) of 23 BRCA2 carriers and 53 (22%) of 237 BRCA noncarriers (P < .001). In the multivariate logistic model, BRCA1 status (odds ratio [OR] = 3.16; 95% CI, 1.55 to 6.42; P = .002), estrogen receptor (ER) negativity (OR = 1.96; 95% CI:1.05 to 3.65; P = .03) and concurrent trastuzumab use (OR = 4.18; 95% CI, 2.04 to 8.57; P < .001) remained as independent significant predictors for a pCR. At a median follow-up of 3.2 years, 69 patients (22%) experienced a disease recurrence or death. No significant differences were noted in survival outcomes with respect to BRCA status and type of NST received. However, among BRCA1 carriers, patients who achieved a pCR had better 5-year RFS (P = .001) and OS (P = .01) rates than patients who did not.

CONCLUSION

BRCA1 status and ER negativity are independently associated with higher pCR rates in patients with breast cancer. Overall prognosis of breast cancer in BRCA carriers is similar to sporadic breast cancers.

Predictive factors for BRCA1/BRCA2 mutations in women with ductal carcinoma in situ

BACKGROUND

It is unclear whether women with ductal carcinoma in situ (DCIS), like their counterparts with invasive breast cancer, warrant genetic risk assessment and testing on the basis of high-risk variables. The authors of this report identified predictive factors for mutations in the breast cancer-susceptibility genes BRCA1 and BRCA2 in women who were diagnosed with DCIS.

METHODS

One hundred eighteen women with DCIS who were referred for genetic counseling and underwent genetic testing for BRCA1/BRCA2 mutations between 2003 and 2010 were included in the study. Logistic regression models were fit to determine the associations between potential predictive factors and BRCA status.

RESULTS

Of 118 high-risk women with DCIS, 27% (n = 32) tested positive for BRCA1/BRCA2 mutations. Of those, 10% (n = 12) and 17% (n = 20) had BRCA1 and BRCA2 mutations, respectively. Age, race, and tumor characteristics did not differ between BRCA noncarriers and carriers. In a multivariate logistic model, ≥2 relatives with ovarian cancer (OC) (odds ratio [OR], 8.81; 95% confidence interval [CI], 1.38-56.29; P = .034), and a score ≥10% according to the BRCAPRO mathematical model for calculating the probability that a particular family member carries a germline BRCA mutation (OR, 6.37; 95% CI, 2.23-18.22; P = .0005) remained as independent significant predictors for a BRCA mutation. Fifty-seven percent of mutation carriers but only 25% of noncarriers underwent prophylactic mastectomy(P = .0037). This difference remained significant for patients aged ≤40 years (P = .025).

CONCLUSIONS

Women who had DCIS and a family history of OC or who had BRCAPRO scores ≥10% had a high rate of BRCA positivity regardless of age at diagnosis. These findings suggest that high-risk patients with DCIS are appropriate candidates for genetic testing for BRCA mutations in the presence of predictive factors even if they do not have invasive breast cancer.