Nipple Discharge and Breast Cancer: What's the Connection?

Is there a connection between unusual nipple discharge and breast cancer?

Before we take a closer look at their possible link, it helps to first define what nipple discharge is.

Nipple discharge refers to the release of fluid from the nipple which can be expressed or spontaneously leak in approximately 50% to 70% of normal women. This type of nipple discharge is termed as “physiological discharge.”

Nipple discharge is typically normal when seen in pregnant or breastfeeding patients. It may also occur associated with changes in menstruation and fibrocystic changes in the breast. 

Normal nipple discharge is milky and tends to affect both breasts (bilateral nipple discharge) and may be seen for up to 3 years after cessation of breastfeeding.

What Are the Characteristics of Normal Nipple Discharge?

Normal nipple discharge is usually yellow, green, or milky in appearance. This discharge occurs only when expressed. And it is of no particular medical concern when it appears without other signs and symptoms.

The discharge associated with pregnancy or breastfeeding is typically milky and may occur spontaneously or on expression.

Breast Cancer and Nipple Discharge: What’s the Connection?

Patients who are not pregnant or breastfeeding yet experience spontaneous nipple discharge should seek consultation with their OB-GYN. If your nipple discharge appears normal but is associated with other symptoms, further consultation with a specialist is recommended.

These symptoms include:

It is important to identify these associated symptoms, as nipple discharge can be an early sign of breast cancer.

What Are the Characteristics of Abnormal Nipple Discharge?

Abnormal nipple discharge occurs spontaneously in non-pregnant and non-breastfeeding women. They are typically clear, brownish, or blood-tinged in appearance, and affect only one breast (unilateral).

Take note, nipple discharge may require further consultation in certain patients:

• Women older than 40 years
• Males

Breast Cancer and Nipple Discharge

Breast cancer and nipple discharge are rarely associated with one another. Approximately less than 5% of women with breast cancer will present with nipple discharge alone. Patients who have nipple discharge associated with cancer typically present with other symptoms such as a breast lump or inverted nipple.

Paget’s disease of the nipple is a type of cancer that may cause blood-stained nipple discharge. It is a condition that causes ulceration and erosion of the skin of the nipple.

What Are Conditions That Can Cause Abnormal Nipple Discharge?

There are several conditions that can cause the onset of nipple discharge and a majority of them are benign. These include the following:

Duct Papilloma

A duct papilloma is a growth within a milk duct of the breast, typically near the nipple. They tend to cause clear or blood-tinged discharge.

Nipple Eczema

Eczema refers to dermatitis or inflammation of the skin of the nipple which is often a consequence of an infection of the breast. This condition tends to cause weeping and/or crusty nipple discharge.

Duct Ectasia

Inflammation and enlargement of the walls of the milk ducts in the breasts cause this condition. It typically occus in women post-menopause, and it may appear yellow, green, or brown.

Excessive Prolactin Production

Your pituitary gland makes the hormone prolactin. This hormone is responsible for the production of milk and the development of the mammary glands.

Certain Medications

Oral contraceptives, hormone replacement medications, nausea medications, antidepressants, and stimulants may cause an increase in prolactin which, in turn, can trigger nipple discharge. 

Other Conditions

Conditions affecting the thyroid or pituitary gland may also cause an excess amount of prolactin production.

What To Expect When Consulting Your Physician

If your nipple discharge is abnormal and you feel the need to seek consultation, here’s what you can expect. Your doctor will begin their investigation with a clinical examination followed by imaging studies of the breast (mammogram, ductogram and/or breast ultrasound). They will request for imaging studies in order to detect any abnormal growths in the breast. 

In the case that these tests show abnormalities, a breast biopsy may be needed. Healthcare practitioners perform breast biopsies in order to obtain samples of abnormal tissues within your breast. These will undergo examination for malignant (cancerous) tissues. 

Learn more about Breast Cancer here.