A diagnosis of a rare breast cancer means you have a type of breast cancer that is not common. Out of every 100 people with breast cancer, 5 cases are a rare subtype. Because there are so few cases, only some doctors have experience in diagnosing and treating them. It’s important to choose a care team that is trained in treating rare breast cancers.
The Rare Breast Cancer Program at Memorial Sloan Kettering Cancer Center (MSK) has that experience. We evaluate and treat about 200 people with early- or advanced-stage rare breast cancer every year.
We have created a whole care team of experts to develop the best plan for you. At your MSK appointment, we will also evaluate whether we have a research study, also known as a clinical trial, for you to consider. We will guide you if you want to enroll in a trial.
A Note From the Program Directors
When you are diagnosed with breast cancer, you may feel isolated, confused, or overwhelmed. If you are diagnosed with a rare breast cancer, you may feel those emotions even more. We are here to help you understand your diagnosis. MSK created this program to develop better treatment options for rare breast cancers. Our promise is to share everything we know, and to research everything we don’t.
As our understanding of breast cancer grows, it is clear there is no one-size-fits-all treatment. The Rare Breast Cancer Program’s mission is to research each rare cancer type to improve how we choose treatments. Each rare type is distinct, yet treatment guidelines have often been based on more common breast cancers.
We will get samples from your tumor with a biopsy or during surgery. We will do special testing on the tumor. The results will help guide your treatment and could help us with research on your type of breast cancer.
The Rare Breast Cancer Program will make sure you get the best treatment for your cancer. We’re here for you and for our future patients, as we improve our knowledge of rare breast cancer types through research.
Nour Abuhadra, MD
Breast Medical Oncologist
Giacomo Montagna, MD, MPH
Rare Types of Breast Cancer
Metaplastic Breast Cancer
Metaplastic breast cancer is a rare type of invasive breast cancer. “Invasive” means it spread from where it began in the breast to nearby healthy tissue. Metaplastic breast cancers have some breast cells, as well as cells that don’t come from the breast. It is a mix of 2 or more types of breast cancer cells, usually carcinoma and sarcoma. Metaplastic breast cancers most often are triple-negative. That means they don’t have the estragon, progesterone, or HER2 receptors that are common in other breast cancers.
Micropapillary Breast Cancer (Invasive Micropapillary Carcinoma)
Micropapillary breast cancer is also called invasive micropapillary carcinoma. It is invasive breast cancer, and often detected as a lump in the center of the breast. Micropapillary carcinomas will very likely spread to the lymph nodes.
Neuroendocrine Breast Cancer
Neuroendocrine tumors in the breast can have different forms. The tumor can be an invasive breast cancer that acts more like a standard breast cancer. It can be neuroendocrine carcinoma of the breast, which is a more aggressive cancer. To make a diagnosis, we look for neuroendocrine markers.
Adenoid Cystic Breast Cancer (Adenoid Cystic Carcinoma)
Adenoid cystic breast cancer is also called adenoid cystic carcinoma. It is made up of abnormal epithelial cells (cells that line an organ) that invade the milk ducts. Adenoid cystic tumors most often are triple-negative. That means they don’t have the estrogen, progesterone, or HER2 receptors that are common in other breast cancers. Adenoid cystic carcinomas generally grow slowly and respond well to treatment. However, there is a type that tends to be more aggressive, called the solid basaloid variant.
Tubular Breast Cancer
Tubular breast cancer is made up of tube-shaped cells. It starts in the milk ducts but usually does not spread past the ducts and surrounding tissue. This cancer grows slowly. It has a better prognosis (outcome) than other rare breast cancers.
Secretory Breast Cancer
Secretory breast cancer most often affects children and young adults, but it can happen at any age. The first symptom is usually a firm, painless lump. This cancer grows slowly and responds well to treatment, even when it has spread to lymph nodes.
Phyllodes tumors start in the connective tissue of the breast, called the stroma. About 3 out of every 4 phyllodes tumors are benign (not cancer). A phyllodes tumor most often is a lump that can grow quickly. It usually does not spread to the lymph nodes. Phyllodes tumors have many types, and they behave differently. The less aggressive type often comes back in the same place. But in rare cases, phyllodes tumors can metastasize (spread) to other parts of the body
How We Support People With Rare Breast Cancers
Understanding Family History
You may have a rare breast cancer because of the genes you were born with. Hereditary cancer is caused by a gene mutation (change) that can be passed down to family members. They affect family members related to you by blood, not through marriage or adoption. Genetic testing and counseling can tell if you have a mutation and what it means for your family members. This genetic information can guide your treatment.
Coping With Side Effects
MSK experts can help manage the side effects of treatment. We offer lymph node biopsy and adjuvant therapies, such as chemotherapy and radiation. If you’re getting chemotherapy, we offer scalp cooling to reduce hair loss. We have ways to manage nausea (feeling like throwing up). Our experts also offer tests to help find out if you really need chemotherapy.
Our Integrative Medicine Service offers therapies and treatments to go along with your cancer care. This includes complementary medicine, such as acupuncture, acupressure, massage, Reiki, exercise, and yoga classes. They can help with symptoms and side effects, such as pain, neuropathy (nerve problems), fatigue (feeling tired), trouble sleeping, stress, anxiety, and mobility.
Nutrition and Eating Well
Counseling, Support Services, and Resources
We have many services to help you through your journey. Our experts offer counseling and support to help you and your family manage anxiety and other emotional concerns related to cancer. We offer support groups and programs, both in person and through live online events. You can meet other people going through a similar experience. Our Patient and Caregiver Peer Support Program connects you and your caregivers to people who have had a similar breast cancer diagnosis.
Social workers are an important part of your care team. They can give you information about how to talk about your diagnosis with your children, parents, work colleagues, and friends. You can have individual consultations with them. Our social workers can talk with you about concerns with paying for your care at MSK.
Sexual Health and Fertility
Cancer treatment can affect your sexual health and interest in sexual activity. Our Sexual Health Program can help with physical symptoms and emotional issues that can affect your sex life. Our Cancer and Fertility Program is run by our fertility nurse specialists. They can help preserve your fertility (ability to get pregnant) if you want to have a child. We will guide you through options, whether you are newly diagnosed or have completed cancer treatment.
Personalized Health Program
MSK Healthy Living is an evidence-based, personalized program with one-on-one support to help you in every aspect of your journey. We will create a personal lifestyle plan tailored to your needs and concerns.
The Latest Research
Join a Clinical Trial
More to come.
Studies and Publications
Neuroendocrine tumours of the breast: a genomic comparison with mucinous breast cancers and neuroendocrine tumours of other anatomic sites. J Clin Pathol. 2022 Jan;75(1):10-17. doi: 10.1136/jclinpath-2020-207052. Epub 2020 Nov 4.
PD-L1 Expression in Metaplastic Breast Carcinoma Using the PD-L1 SP142 Assay and Concordance Among PD-L1 Immunohistochemical Assays. Am J Surg Pathol. 2021 Sep 1;45(9):1274-1281. doi: 10.1097/PAS.0000000000001760.
Poor response to neoadjuvant chemotherapy in metaplastic breast carcinoma. NPJ Breast Cancer. 2021 Jul 22;7(1):96. doi: 10.1038/s41523-021-00302-z.
The genomic landscape of metastatic histologic special types of invasive breast cancer. NPJ Breast Cancer. 2020 Oct 14;6:53. doi: 10.1038/s41523-020-00195-4. eCollection 2020.
Genomic and transcriptomic heterogeneity in metaplastic carcinomas of the breast. NPJ Breast Cancer. 2017 Dec 1;3:48. doi: 10.1038/s41523-017-0048-0. eCollection 2017.
The Landscape of Somatic Genetic Alterations in Metaplastic Breast Carcinomas. Clin Cancer Res. 2017 Jul 15;23(14):3859-3870. doi: 10.1158/1078-0432.CCR-16-2857. Epub 2017 Feb 2.
The genetic landscape of breast carcinomas with neuroendocrine differentiation. J Pathol. 2017 Feb;241(3):405-419. doi: 10.1002/path.4837. Epub 2016 Dec 26.
IDH2 Mutations Define a Unique Subtype of Breast Cancer with Altered Nuclear Polarity. Cancer Res. 2016 Dec 15;76(24):7118-7129. doi: 10.1158/0008-5472.CAN-16-0298. Epub 2016 Oct 20.
Triple-negative breast cancer: the importance of molecular and histologic subtyping, and recognition of low-grade variants. NPJ Breast Cancer. 2016 Nov 16;2:16036. doi: 10.1038/npjbcancer.2016.36. eCollection 2016.
Genetic events in the progression of adenoid cystic carcinoma of the breast to high-grade triple-negative breast cancer. Mod Pathol. 2016 Nov;29(11):1292-1305. doi: 10.1038/modpathol.2016.134. Epub 2016 Aug 5.
Genetic hallmarks of recurrent/metastatic adenoid cystic carcinoma. J Clin Invest. 2019 Oct 1;129(10):4276-4289. doi: 10.1172/JCI128227.
The Genomic Landscape of Mucinous Breast Cancer. J Natl Cancer Inst. 2019 Jul 1;111(7):737-741. doi: 10.1093/jnci/djy216.
Phyllodes tumors with and without fibroadenoma-like areas display distinct genomic features and may evolve through distinct pathways. NPJ Breast Cancer. 2017 Oct 12;3:40. doi: 10.1038/s41523-017-0042-6. eCollection 2017.
Survival Outcomes for Metaplastic Breast Cancer Differ by Histologic Subtype. Ann Surg Oncol. 2021 Aug;28(8):4245-4253. doi: 10.1245/s10434-020-09430-5. Epub 2021 Jan 2.