Pregnancy After Breast Cancer in Young BRCA Carriers: An International Hospital-Based Cohort Study

Importance

Young women with breast cancer who have germline pathogenic variants in BRCA1 or BRCA2 face unique challenges regarding fertility. Previous studies demonstrating the feasibility and safety of pregnancy in breast cancer survivors included limited data regarding BRCA carriers.

Objective

To investigate cumulative incidence of pregnancy and disease-free survival in young women who are BRCA carriers.

Design, Setting, and Participants

International, multicenter, hospital-based, retrospective cohort study conducted at 78 participating centers worldwide. The study included female participants diagnosed with invasive breast cancer at age 40 years or younger between January 2000 and December 2020 carrying germline pathogenic variants in BRCA1 and/or BRCA2. Last delivery was October 7, 2022; last follow-up was February 20, 2023.

Exposure

Pregnancy after breast cancer.

Main Outcomes and Measures

Primary end points were cumulative incidence of pregnancy after breast cancer and disease-free survival. Secondary end points were breast cancer-specific survival, overall survival, pregnancy, and fetal and obstetric outcomes.

Results

Of 4732 BRCA carriers included, 659 had at least 1 pregnancy after breast cancer and 4073 did not. Median age at diagnosis in the overall cohort was 35 years (IQR, 31-38 years). Cumulative incidence of pregnancy at 10 years was 22% (95% CI, 21%-24%), with a median time from breast cancer diagnosis to conception of 3.5 years (IQR, 2.2-5.3 years). Among the 659 patients who had a pregnancy, 45 (6.9%) and 63 (9.7%) had an induced abortion or a miscarriage, respectively. Of the 517 patients (79.7%) with a completed pregnancy, 406 (91.0%) delivered at term (≥37 weeks) and 54 (10.4%) had twins. Among the 470 infants born with known information on pregnancy complications, 4 (0.9%) had documented congenital anomalies. Median follow-up was 7.8 years (IQR, 4.5-12.6 years). No significant difference in disease-free survival was observed between patients with or without a pregnancy after breast cancer (adjusted hazard ratio, 0.99; 95% CI, 0.81-1.20). Patients who had a pregnancy had significantly better breast cancer-specific survival and overall survival.

Conclusions and Relevance

In this global study, 1 in 5 young BRCA carriers conceived within 10 years after breast cancer diagnosis. Pregnancy following breast cancer in BRCA carriers was not associated with decreased disease-free survival.

Trial Registration

ClinicalTrials.gov Identifier: NCT03673306.

Abstract P2-09-16: Clinicopatological features and outcome of breast cancer in CHEK2 germline mutation carriers

Background: Carriers of CHEK2 germline mutations are at moderately increased (20-40%), lifetime risk for developing breast cancer (BC), in part depending on specific family history and mutation type and location. CHEK2 mutation associated BC is commonly associated with positive estrogen receptor(ER) tumor subtype, but other tumor features are less evident. Long term follow up and outcome of patients with CHEK2 -associated BC has not been reported. The clinical and tumoral features as well as and clinical outcome of a consecutive series of 57 BC patients (63 primary tumors) harboring pathogenic CHEK2 mutation is presented. Methods: Following IRB approval, hospital records from 3 major cancer centers in Israel were reviewed to identify female CHEK2 pathogenic/likely pathogenic sequence variant (P/LPSV) carriers who were diagnosed with BC between 2001-2021.Relevant clinical features, tumor data, treatment details and outcome were retrieved and. Mann-Whitney U-test was performed for continuous variables and descriptive statistics were used for non-continuous variables.Results:104 BC cases with documented CHEK2 sequence variant were obtained. 57 were carriers of CHEK2germline P/LPSV, and 63 primary tumors were diagnosed in these participants. Median age at diagnosis was 50 years (mean 51, range 31-73) and median follow up time of 23.5 months (mean 47,range 1-228). Six of 57 [10.5%] were diagnosed with synchronous bilateral tumors, and 6 [10.5%]with multifocal ipsilateral tumors. Twenty-three (41%) of the invasive tumors had positive regional lymph nodes at diagnosis and median tumor size was 1.2cm (mean 1.9, range 0.3-11.3cm). Seventy seven percent were invasive ducal carcinoma, 8% were invasive lobular, 11% DCIS, and two cases -unknown histology. Fifty-seven of 63 tumors (90%) were ER positive, and only two cases were triple negative. Ten (16%)tumors were HER2 positive. Most tumors (66%) were intermediate grade, 18% - low-grade, and 16%- high-grade tumors. Eighty percent opted for breast conserving surgery and 29 received chemotherapy, all were AC-T regimen, with anti HER2 agents in HER2 positive tumors. The most common PSV were c.1100delC (17 patients) and p.S428P (17 patients). Mean age at diagnosis for these two PSVs were 47 and 57 years, respectively (p=0.00438). Seven (12%) patients developed metastatic disease during the follow up period. Conclusion: This descriptive study shows some unique features of CHEK2 associated BC: early age at diagnosis(for the c.1100delC PSV) and high percentage of ER positivity. Synchronous and multifocal tumors were common. Further long term follow up and larger detailed description is warranted in this unique population.

Citation Format: Shir Schlosser, Rinat Bernstein Molho, Natalia Karminsky, Daphna Barsuk, Yael Goldberg, Eitan Friedman, Rinat Yerushalmi, Keren Drumea, Inbal Kedar, Irina Jiveliouk, Merav Akiva Ben David. Clinicopatological features and outcome of breast cancer in CHEK2 germline mutation carriers [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-09-16.

The spectrum of tumors harboring BAP1 gene alterations

Germline mutations in the BRCA1-associated protein (BAP1) gene (MIM # 603089) are associated with a substantially increased risk for developing melanoma, mesothelioma, and renal cell carcinoma. Somatic inactivation of the BAP1 gene was noted in these and other tumors types, including esophageal cancer and cholangiocarcinoma. The favorable response of BRCA1/2-associated tumors to poly (ADP-ribose) polymerase (PARP) inhibitor therapy, raises the possibility that tumors harboring BAP1 mutations may exhibit similar sensitivity to PARP inhibitor therapy. Given the possibility that BAP1 alterations may have therapeutic implications, this study was aimed to describe the spectrum of tumors that harbor BAP1 alterations. The Foundation Medicine database was queried for known or likely pathogenic BAP1 genomic variants through July 2019. Overall, 4982/374,694 (1.81%) tumors harbored pathogenic BAP1 genomic alterations. Highest rates were noted in mesothelioma (45.24%), cholangiocarcinoma (13.37%), renal cell carcinoma (10.52%), thymic cancer (8.16%), salivary gland cancer (6.18%), and melanoma (5.1%). There were 59 unique BAP1 short variants detected in at least 10 samples. More same tissue tumors of squamous cell histology harbored BAP1 alterations than adenocarcinomas. The current study highlights tumor types that display higher than previously appreciated rates of somatic BAP1 genomic alterations.

Abstract P5-08-10: Surveillance for BRCA1/2 mutation carriers - Is "early detection" really early enough?

Background: Annual MRI screening is associated with a significant reduction in the incidence of advanced-stage breast cancer (BC) in BRCA1/2 mutation carriers. The purpose of our study was to assess stage at diagnosis and therapeutic approaches in BRCA1/2 carriers and compare these parameters in women who developed BC while adhering to the recommended surveillance scheme ("known carriers"), with BC cases who became aware of their BRCA carreirship after BC diagnosis ("latent carriers").

Methods: Retrospective data were collected on BRCA1/2 mutation carriers treated for BC at the Sheba medical center, both at the oncology institute and the high-risk clinic. The main variables evaluated were tumor characteristics, stage at diagnosis, and treatment decisions.

Results: Overall, 529 BRCA1/2 carriers were identified. At the time of data summary, relevant clinical information was available for 297 patients. Median follow-up time was 77.4 months (range, 2.5-519).

The group of known carriers included 95 women (median age at diagnosis 41.9 [range 27.8-80.3 years]), 70 (74%) were BRCA1 carriers, 23 (24%) BRCA2 carriers, and 2 (2.1%) carried mutations in both genes. The median age at diagnosis of 202 latent carriers was 43.7 (range 23.8-75 years), p=0.8284. Of latent carriers 117 (58%) were BRCA1 mutation carriers and 85 (42%) harbored a BRCA2 mutation.

In the group of known carriers, 19% were diagnosed with carcinoma in situ (DCIS) vs. 5% in the group of latent carriers (p=00012). Stage T1N0 disease was diagnosed in 54/95 (56.8%) of known carriers vs. 59/202 (29.2%) of latent carriers (p<0.00001). Node-positive disease was diagnosed in 11/95 (11.6%) of known carriers vs. 98/202 (48.5%) of latent carriers (p<0.00001). Metastatic disease was diagnosed at presentation in none of the known carriers vs. 4/202 (2%) of latent carriers (p=0.16758).

Overall, in the group of known carriers (including all stages) 46/95 (48.4%) received neoadjuvant (n=12) or adjuvant (n=34) chemotherapy (71.7% of them for triple-negative disease), and 41/95 (43.2%) received radiotherapy. In the group of latent carriers, 162/202 (80.2%) received neoadjuvant (n=74) or adjuvant (n=88) chemotherapy (p<0.00001), 59.3% of them for triple-negative disease, and 173/202 (85.6%) underwent radiotherapy.

Contralateral risk-reducing mastectomy (CRRM) was performed by 59/95 (62%) of the known carriers, 73% of them at the time of primary tumor resection and the rest – at a later stage. Among latent carriers, 82/202 (40.6%) underwent CRRM, 44% at the time of primary tumor resection (p=0.00054).

Conclusions: As expected, diagnosis of early stage disease (DCIS or T1N0) was significantly higher in the group of known BRCA1/2 carriers - disease that was diagnosed in the course of tight surveillance. Yet, despite this early stage diagnosis, chemotherapy and radiotherapy treatments were employed in a substantial proportion of these cases. Healthy BRCA1/2 mutation carriers should be informed about these chemotherapy and radiotherapy rates while discussing risk-reducing surgical options. There is an urgent need for a more accurate ability to predict individual mutation carrier cancer risk, as well as tools for selection of patients with stage I triple-negative disease who will do well without chemotherapy.

Citation Format: Rinat Bernstein Molho, Bella Kaufman, Merav A Ben David, Miri Sklair-Levy, Yael Laitman, Eitan Friedman. Surveillance for BRCA1/2 mutation carriers - Is "early detection" really early enough? [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 P5-08-10.

De novo pathogenic germline variant in PALB2 in a patient with pancreatic cancer

De novo mutations in the major breast/ovarian cancer susceptibility genes BRCA1 and BRCA2 are rare. De novo mutations in the PALB2 gene have never been reported. Here we report a de novo PALB2 germ line mutation (c.3455delC (p.Pro1152Hisfs*11) in a patient with pancreatic cancer, where non-paternity and somatic parental mosaicism have to the extent possible been excluded as a mechanism for detecting the de novo mutation. The lack of previous reports on de novo PALB2 mutations maybe the limited number of PALB2germline mutations reported overall.

The spectrum of BRCA1 and BRCA2 pathogenic sequence variants in Middle Eastern, North African, and South European countries

BRCA1 BRCA2 mutational spectrum in the Middle East, North Africa, and Southern Europe is not well characterized. The unique history and cultural practices characterizing these regions, often involving consanguinity and inbreeding, plausibly led to the accumulation of population-specific founder pathogenic sequence variants (PSVs). To determine recurring BRCA PSVs in these locales, a search in PUBMED, EMBASE, BIC, and CIMBA was carried out combined with outreach to researchers from the relevant countries for unpublished data. We identified 232 PSVs in BRCA1 and 239 in BRCA2 in 25 of 33 countries surveyed. Common PSVs that were detected in four or more countries were c.5266dup (p.Gln1756Profs), c.181T>G (p.Cys61Gly), c.68_69del (p.Glu23Valfs), c.5030_5033del (p.Thr1677Ilefs), c.4327C>T (p.Arg1443Ter), c.5251C>T (p.Arg1751Ter), c.1016dup (p.Val340Glyfs), c.3700_3704del (p.Val1234Glnfs), c.4065_4068del (p.Asn1355Lysfs), c.1504_1508del (p.Leu502Alafs), c.843_846del (p.Ser282Tyrfs), c.798_799del (p.Ser267Lysfs), and c.3607C>T (p.Arg1203Ter) in BRCA1 and c.2808_2811del (p.Ala938Profs), c.5722_5723del (p.Leu1908Argfs), c.9097dup (p.Thr3033Asnfs), c.1310_1313del (p. p.Lys437Ilefs), and c.5946del (p.Ser1982Argfs) for BRCA2. Notably, some mutations (e.g., p.Asn257Lysfs (c.771_775del)) were observed in unrelated populations. Thus, seemingly genotyping recurring BRCA PSVs in specific populations may provide first pass BRCA genotyping platform.

Assessment of breast cancer risk in BRCA carriers with ovarian cancer: Evaluation of data from longitudinal observation

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Background: To confirm data from older studies reporting reduced risks of breast cancer (BC) in BRCA mutated (BRCA+) ovarian cancer (OC) patients and to re-evaluate BC surveillance and/or prophylactic mastectomy in OC patients. Methods: Data on 430 BRCA+ mutation carriers diagnosed with OC between 2000 and 2017 in 6 medical centers (one in the USA and five in Israel) were analyzed. Data included demographics, breast surveillance type, family history, BRCA mutation types, timing of BC diagnosis (before or after OC diagnosis) and family history of cancer. Results: Median age at diagnosis of OC was 55.4 years (range, 31.3-90) and median follow-up was 4.6 years. Most patients were BRCA1 (66.6%), and 35.7% had 185delAG. Most patients (68.4%) were Ashkenazi Jews, 27.4% had a family history of BC and 16.5% were diagnosed with BC before OC. Five percent developed BC following OC diagnosis with a median time to BC diagnosis of 68 months (range, 11-210). Of those diagnosed with BC, 50% had triple-negative BC, 40% had luminal B ER+, PR-, Her2-neg and 10% had luminal A -ER+, PR+, her2-neg. There was a non-significant increase in BC after OC, and in BC prior to OC diagnosis; there was no correlation of BC with family history. No definite deaths from BC were recorded. Conclusions: The incidence of BC after OC diagnosis in the BRCA+ population at a median follow-up of 4.6 years is consistent with prior series. Prophylactic bilateral Surveillance measures should be re-evaluated in this population and may only be needed in long-term disease-free survivors and/or subpopulations to be identified. Clinical trial information: 07-146.

The complexity of management of pregnancy-associated malignant soft tissue and bone tumors

OBJECTIVE

The incidence of musculoskeletal tumors during pregnancy is very low. The aim of this study was to summarize our experience in treating a large cohort of pregnant patients diagnosed with these rare tumors.

METHODS

Women diagnosed with musculoskeletal tumors during pregnancy or immediately after delivery were identified retrospectively in our database between 1996 and 2006. Relevant maternal and neonatal data were collected.

RESULTS

Twenty patients, 8 with bone sarcomas (BS) and 12 with soft tissue sarcomas (STS) were identified. Two women were treated by wide excision of mass during pregnancy. In all other cases oncological treatment was delayed until delivery or termination of pregnancy. Vaginal delivery was possible in 9 patients, cesarean section was performed in 7, spontaneous abortion occurred in 1, and 3 underwent termination of pregnancy. Three newborns were premature, but normal growth and development were observed. Different techniques of fertility preservation were used in our patients. Five patients with BS and 5 patients with STS received preoperative chemotherapy, with different grades of toxicity. The degree of tumor necrosis tended to correlate with dose-intensity of chemotherapy. Seven patients with BS received adjuvant chemotherapy. Two patients with STS received adjuvant chemotherapy, two - radiotherapy, and four - both modalities. Median disease-free survival was 15.1 months, median overall survival - 25.4 months.

CONCLUSIONS

Musculoskeletal tumors diagnosed during pregnancy, or after delivery, do not appear to have a significant impact on the prognosis. A multidisciplinary team should tailor the oncological approach individually.