Breast Cancer

Familial Breast Cancer Research Unit

Read our newsletters to learn about the latest hereditary cancer research updates.
Issue 1 – 2021
Issue 2 – 2022
Issue 3 – 2025

The Familial Breast Cancer Research Unit, led by Tier 1 Canada Research Chair Dr. Steven Narod, is a world leader in the study of inherited cancers. With a particular focus on breast and ovarian cancers, Dr. Narod leads this WCRI team in the study of genetic mutations that are known to increase the risk of many cancers – most notably the BRCA1 and BRCA2 mutations. Through its extensive research, publications, data collection, genetic testing programs and collaborations, the team has become an internationally renowned leader in identifying and developing effective strategies to prevent and manage these cancers women and families with a high inherited risk.

Virtual Hereditary Cancer Series

This free virtual series, run with The Peter Gilgan Centre for Women’s Cancers at Women’s College Hospital in partnership with the Canadian Cancer Society, highlights the most relevant advances in hereditary breast and ovarian cancer research. Topics are tailored to women who carry a BRCA1 and BRCA2 mutation.

Missed a 2022 webinar? Watch it here

Missed a 2021 webinar? What it here

Genetic Counseling

The Familial Breast Cancer Research Unit provides genetic testing and other clinical services to families who may carry a BRCA1/2 genetic mutation. Genetic counselors based at the unit offer information and support to women and their families about their options. Their interactions with patients have also helped inspire new research questions. By documenting the experiences of women living with a high risk of developing cancer, the team enhances and expands Cancer Information Registries and additional breast cancer resources, improving the world’s understanding of inherited breast and ovarian cancers. For example, WCRI’s findings have helped to justify the expense of offering MRI breast screening to high-risk women, and have documented the efficacy of specific surgical and medical interventions.

International Capacity Building

Dr. Steven Narod leads international collaborations with researchers studying the prevalence and impact of BRCA1 and BRCA2 mutations. The incidence of these genes varies in many diverse populations around the world. Dr. Narod currently leads new research projects in Mexico, Colombia, Venezuela, Vietnam, Uruguay, Greece, Pakistan, Peru, and Costa Rica, focusing on both genetic and environment factors that contribute to higher than normal incidences of cancer in these specific populations. Since no genetic testing or genetic counselling is currently offered in these countries, these collaborations will ultimately help build research skills and the capacity to study cancer genetics.

Research Team

Key Findings

Get Involved

Our Team

Steven Narod, MD, FRCP

Kelly Metcalfe, RN, PhD

Joanne Kotsopoulos, PhD

Mohammad Akbari, MD, PhD

Vasily Giannakeas, PhD

David Lim, MD, PhD

Aletta Poll, MSc

Angelina Tryon, MSc, CGC

Alyssa Joynt, MSc, CGC

Ping Sun, PhD

Ellen MacDougall, MBT

Christianne Hoey, MSc

Patricia Nguyen, PhD

Shana Kim, MSc

Pooja Patel, BSc

Emily Panzarella, BSc

Rebecca Raj, BSc

Angela Cheriyan, BSc

Banafsheh Mesbani, BSc

Mastoora Rizai, BSc

Alessandra Rodriguez, BSc

Siham Karamali, BSc

Mehar Chahal, BSc

Neda Zemani, PhD candidate

Victoria Sopik, PhD, Postdoctoral Fellow

Katherine Pullella, PhD, Postdoctoral Fellow

Anita Rajkumar, BSc, MSc Candidate

Cynthia Ji, BSc Candidate

Last updated December 16, 2024.

Learn More

For more information about our unit or if you need assistance, please contact:

Familial Breast Cancer Research Unit

Women’s College Research Institute
76 Grenville Street, 6th Floor, Toronto ON M5S 1B2
Phone: (416) 351-3765
Fax: (416) 351- 3767
Email: narodstudy@wchospital.ca

Findings: Familial Breast Cancer Research Unit

Carriers of the BRCA1 and BRCA2 gene mutations who have children are significantly more likely to develop breast cancer by age 40 than carriers who have not had any children. Each pregnancy is associated with an increased cancer risk. An early first pregnancy does not mean protection for carriers of BRCA1 or BRCA2 mutations.¹

Women who have a BRCA1 mutation and breast-fed for a cumulative total of more than one year had a statistically significant reduced risk of breast cancer.²

Oral-contraceptive use may reduce the risk of ovarian cancer in women with mutations in the BRCA1 or BRCA2 gene.³

Among BRCA1 mutation carriers, women who first used oral contraceptives before 1975, who used them before age 30, or who used them for five or more years may have an increased risk of early-onset breast cancer. Oral contraceptives do not appear to be associated with risk of breast cancer in BRCA2 carriers, but data for BRCA2 carriers is limited.⁴

The use of fertility medications does not adversely affect the risk of breast cancer among BRCA mutation carriers. However, the impact of fertility drug use among BRCA mutation carriers has not been studied closely due to the small number of carriers who have used fertility drugs. Any findings should be interpreted with caution. Further studies are required in this field.⁵

Tubal ligation is a suitable option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.⁶

The high incidence of ovarian cancer suggests that oophorectomy (surgical removal of the ovaries) should be recommended in female BRCA1 and BRCA2 mutation carriers with a diagnosis of breast cancer, especially those with stage I disease. Breast cancer systemic therapy did not significantly alter the risk of ovarian cancer.⁷

Oophorectomy is an effective means of reducing the risk of breast cancer in carriers of BRCA1 mutations. The data suggests oophorectomy is protective in BRCA2 carriers as well, but this needs to be confirmed in other studies.⁸

Oophorectomy is associated with a reduced risk of ovarian and fallopian tube cancer in high-risk women, although there is a substantial residual risk for peritoneal cancer in BRCA1 and BRCA2 mutation carriers following prophylactic salpingo-oophorectomy (a type of preventive surgery performed by removing the fallopian tubes and ovaries).⁹

Tamoxifen, a drug used in the treatment of breast cancer, has been shown to reduce the risk of contralateral (affecting both breasts) breast cancer in women with mutations in the BRCA1 or BRCA2 gene. The protective effect of tamoxifen seems independent of that of removal of the ovaries.¹⁰

The protective effect of tamoxifen was not seen among women who had their ovaries removed but this subgroup was small. In contrast, a strong protective effect of tamoxifen was apparent among women who were premenopausal or who had undergone natural menopause.¹¹

The risk of contralateral breast cancer in women with a BRCA mutation is approximately 40 per cent at 10 years after the first breast cancer diagnosis, and is reduced in women who take tamoxifen or who undergo an ovary-removal surgery.¹²

We found no association between ever having screening mammography and risk of breast cancer. Prospective studies are needed to confirm the results.¹³

Early chest X-rays may be a risk factor for breast cancer in BRCA1 carriers.¹⁴

Men with BRCA2 mutations have been found to be at increased risk of developing prostate cancer. It may be important to develop targeted chemotherapies to treat prostate cancer in men with a BRCA2 mutation.¹⁵

1. Jernström H, Lerman C, Ghadirian P, Lynch H, Weber B, Garber J, Daly M, Olopade O, Foulkes WE, Warner E, Brunet J-S and Narod SA. Pregnancy and risk of early breast cancer in carriers of BRCA1 and BRCA2. Lancet, 354:1846-50, 1999.

2. Jernström H, Lubinski L, Lynch HT, Ghadirian P, Neuhausen S, Isaacs C, Weber B, Horsman D, Rosen B, Foulkes WD, Friedman E, Gershoni-Baruch R, Ainsworth P, Daly M, Garber J, Olsson H, Sun P, Narod SA. Breast-feeding and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers. J Natl Cancer Inst, 96:1094-8, 2004.

3. Narod SA, Risch H, Moslehi R, Neuhausen S, Moller P, Olsson H, Provencher D, Radice P, Evans G, Bishop S, Brunet J-S and Ponder B. Oral contraceptives and the risk of hereditary ovarian cancer. N Engl J Med, 339:424-8, 1998.

4. Narod SA, Dubé M-P, Klijn J, Lubinski J, Lynch HT, Ghadirian P, Provencher D, Heimdal K, Moller P, Isaacs C, Weber B, Friedman E, Gershoni-Baruch R, Rennert G, Pasini B, Wagner T, Daly M, Garber JE, Neuhausen S, Robson M, Offit K, Ainsworth P, Olsson H, Evans G, Osborne M, Couch F, Foulkes W, Warners E, Kim-Sing C, Olopade O, Tung N, Saal HM, Weitzel J, Merajver S, Gauthier-Villars M, Jernstrom H, Sun P, Brunet J-S. Oral contraceptives and the risk of breast cancer in BRCA1 and BRCA2 carriers. J Natl Can Inst, 94:1773-9, 2002.

5. Pal T, Vadaparampil S, Betts J, Miree C, Li S, Narod SA. BRCA1/2 in high-risk African American women with breast cancer: providing genetic testing through various recruitment strategies. Genet Test, 12:401-7, 2008.

6. Narod SA, Sun P, Ghadirian P, Lynch H, Isaacs C, Garber J, Weber B, Karlan B, Fishman D, Rosen B, Tung N, Neuhausen SL and the Hereditary Ovarian Cancer Clinical Study Group. Tubal ligation and the risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: A case-control study. Lancet, 357:1467-70, 2001.

7. Metcalfe K, Lynch H, Ghadirian P, Tung N, Olivotto I, Foulkes W, Warner E, Olopade O, Eisen A, Weber B, McLennan J, Sun P, Narod SA. The risk of ovarian cancer after breast cancer in BRCA1 and BRCA2 carriers. Gynecol Oncol, 96:222-6, 2005.

8. Eisen A, Lubinski J, Klijn J, Moller P, Lynch H, Offit K, Weber B, Rebbeck T, Neuhausen S, Ghadirian P, Foulkes W, Gershoni-Baruch R, Friedman E, Rennert G, Isaacs C, Kim-Sing C, Ainsworth P, Couch F, Garber J, Daly M, Rosen B, Olopade O, Karlan B, Tung N, Saal H, Weitzel J, Eng C, Sun P, Narod SA. Breast cancer risk following bilateral oophorectomy in BRCA1 and BRCA2 mutation carriers: An international case-control study. J Clin Oncol, 23: 7491-6, 2005.

9. Finch A, Beiner M, Lubinksi J, Lynch HT, Moller P, Rosen B, Murphy J, Ghadirian P, Friedman E, Foulkes WD, Kim-Sing C, Wagner T, Tung N, Couch F, Stoppa-Lyonnet D, Ainsworth P, Daly M, Pasini B, Gershoni-Baruch R, Eng C, Olopade OI, Mclennan J, Karlan B, Sun P, Narod SA. Salpingo-oophorectomy and the risk of ovarian, fallopian and peritoneal cancers in women with BRCA1 or BRCA2 mutations. JAMA, 96:185-92, 2006.

10. Narod SA, Brunet J-S, Ghadirian P, Robson M, Heimdahl K, Neuhausen S, Stoppa-Lyonnet D, Lerman C, Radice P, de los Rios P, Weber B, Lynch H for the Hereditary Breast Cancer Clinical Study Group. Tamoxifen and the risk of contralateral breast cancer in BRCA1 and BRCA2 carriers: a case-control study. Lancet, 356:1876-81, 2000.

11. Gronwald J, Tung N, Foulkes WD, Offit K, Gershoni R, Daly M, Kim-Sing C, Olsson H, Ainsworth P, Eisen A, Saal H, Friedman E, Olopade O, Osborne M, Weitzel J, Lynch HT, Ghadirian P, Lubinski J, Sun P, Narod SA and the Hereditary Breast Cancer Clinical Study Group. Tamoxifen and contralateral breast cancer in BRCA1 and BRCA2 carriers: An update. Int J Cancer, 118:2281-4, 2006.

12. Metcalfe K, Lynch HT, Ghadirian P, Tung N, Olivotto I, Warner E, Olopade OI, Eisen A, Weber B, McLennan J, Sun P, Foulkes WD, Narod SA. Contralateral breast cancer in BRCA1 and BRCA2 mutation carriers. J Clin Oncol, 22:2328-35, 2004.

13. Narod SA, Lubinksi J, Ghadirian P, Lynch HT, Moller P, Foulkes WD, Rosen B, Kim-Sing C, Isaacs C, Domchek S, Sun P, and the Hereditary Breast Cancer Clinical Study Group. Screening mammography and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers. Lancet Oncol, 5:402-406, 2006.

14. Gronwald J, Pijpe A, Byrski T, Huzarski T, Stawicka M, Cybulski C, Leeuwen F, Lubinski J, Narod SA. Early radiation exposures and BRCA1-associated breast cancer in young women from Poland. Breast Cancer Res Treat. 112:581-4, 2008.

15. Narod SA, Neuhausen S, Vichodez G, Armel S, Lynch HT, Ghadirian P, Cummings S, Olopade O, Couch F, Wagner T, Warner E, Foulkes WD, Saal H, Weitzel J, Tulman A, Poll AS, Nam R, Sun P and the Hereditary Breast Cancer Study Group. Rapid progression of prostate cancer in men with a BRCA2 mutation. Br J Cancer, 99:371-4, 2008.

Training Opportunities

There are many different forms of training available at the Familial Breast Cancer Research Unit, from academic supervision to summer student volunteer positions. If you are interested in finding out more about these opportunities, please contact us at narodstudy@wchospital.ca.

Research Participation

We appreciate your interest in our research. Our studies would not be possible without the ongoing support, dedication, and collaboration from the many women that participate in them. We are actively recruiting interested participants for our many initiatives. If you are unsure if you are eligible to participate in a study, one of our staff members would be happy to help you.