Rare Breast Cancer

Rare Breast Cancer

Hispanic female breast cancer patient smiling.

Michelle Villagomez was treated for metaplastic breast cancer by experts in MSK’s Rare Breast Cancer Program. “The MSK team really helped me go through this stressful time. The nurses and doctors are all wonderful at letting you know they’ve seen it before.”

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’s trained to treat rare breast cancers.

The Rare Breast Cancer Program at Memorial Sloan Kettering Cancer Center (MSK) has that experience. Every year, we evaluate and treat about 200 people with rare breast cancer in early or more advanced stages.

We have created a whole care team of experts to make 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, that’s right for you. We will guide you if you want to join a clinical trial.

A note from the program directors

When you learn you have breast cancer, you may feel isolated, confused, or overwhelmed. If you’re diagnosed with a rare breast cancer, you may feel those emotions even more. 

We’re 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 what do not know.

As our understanding of breast cancer grows, it’s clear treatment will not be the same for each person.  The Rare Breast Cancer Program’s mission is to research each rare cancer type so we can improve how we choose treatments. Each rare type is distinct. But treatment guidelines often are based on the more common types of breast cancers.

MSK medical oncologist Nour Abuhadra and surgeon Giacomo Montagna, both of whom specialist in treating breast cancer

Co-Directors of the Rare Breast Cancer Program (from left) Nour Abuhadra and Giacomo Montagna

We will get samples from your tumor during a biopsy or surgery. We will do special testing on the tumor. The results will help guide your treatment. They also could help us with research on the type of breast cancer you have.

The Rare Breast Cancer Program will make sure you get the best treatment. 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
Breast Surgeon

Advisory Committee
Don't be afraid to ask questions or get a second opinion. I did and found out MSK is a wonderful place.
Michelle Villagomez patient

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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 started in the breast to nearby healthy tissue. Metaplastic breast cancers have some breast cells, as well as cells that do not come from the breast. It’s 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 do not 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’s invasive breast cancer, and often found as a lump in the center of the breast. Micropapillary carcinomas very likely will spread to the lymph nodes.

Neuroendocrine Breast Cancer

Neuroendocrine tumors in the breast can have a few 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’s made up of abnormal (not normal) epithelial cells that invade the milk ducts. Epithelial cells are cells that line an organ.

Adenoid cystic tumors most often are triple-negative. That means they do not 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. Most often, it does not spread past the ducts and surrounding tissue. This cancer grows slowly. It has a better prognosis (treatment result) 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 most often is a firm, painless lump. This cancer grows slowly. It responds well to treatment, even when it has spread to lymph nodes.

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 change (mutation or variant). It 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.

Integrative Medicine

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

Our food and nutrition team can help you keep a healthy diet during breast cancer treatment. They can help you eat in a way that lowers your risk for the disease. They will help you understand and cope with nutritional challenges, including managing digestion problems and changes in taste.

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.

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 program based on scientific evidence. It offers personal one-on-one support to help you in every aspect of your journey. We will create a personal lifestyle plan just for your needs and concerns.

Expertise To Treat Metaplastic Breast Cancer From MSK’s Rare Breast Cancer Program
Patients like Michelle benefit from the specialized skills of experts in MSK’s Rare Breast Cancer Program.

The Latest Research

Join a Clinical Trial

More to come.

Studies and Publications

Molecular characterization and prospective evaluation of pathological response and outcomes with neoadjuvant therapy in metaplastic triple-negative breast cancer. Clin Cancer Res. 2022 May 4.

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.

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