Breast cancer types

Types of breast cancer

Breast cancer is not a single disease. It is a family of diseases, each with its own behaviour and its own treatment. Knowing the type brings clarity.

90%+of breast cancers are invasive ductal or lobular carcinomas11topics in this section

The types at a glance

Breast cancer is not a single disease. The main types differ in where they start, how they behave and how they are treated.

D

Ductal carcinoma in situ (DCIS)

DCIS is the most common non-invasive breast cancer: abnormal cells lining the milk ducts that have not spread beyond them.

I

Invasive ductal carcinoma (IDC)

IDC is the most common breast cancer. It starts in a milk duct and crosses the wall to invade the nearby breast tissue.

I

Invasive lobular carcinoma (ILC)

ILC starts in the milk-producing lobules and spreads through the breast in subtle, linear ways, which can make it harder to feel.

T

Triple-negative breast cancer (TNBC)

TNBC lacks the three receptors that fuel most breast cancers, so it does not respond to hormone therapy or anti-HER2 drugs — but it responds remarkably well to chemotherapy.

I

Inflammatory breast cancer (IBC)

Inflammatory breast cancer is rare and aggressive. Its first signs are not a lump but redness, swelling and warmth — it can look like an infection.

M

Metastatic breast cancer (MBC)

Metastatic breast cancer means the cancer has spread beyond the breast to other organs. It is stage 4 — a chronic condition to manage, not a sentence.

Section overview

Ductal carcinoma in situ (DCIS)

DCIS is the most common non-invasive breast cancer: abnormal cells lining the milk ducts that have not spread beyond them.

Invasive ductal carcinoma (IDC)

IDC is the most common breast cancer. It starts in a milk duct and crosses the wall to invade the nearby breast tissue.

Invasive lobular carcinoma (ILC)

ILC starts in the milk-producing lobules and spreads through the breast in subtle, linear ways, which can make it harder to feel.

Triple-negative breast cancer (TNBC)

TNBC lacks the three receptors that fuel most breast cancers, so it does not respond to hormone therapy or anti-HER2 drugs — but it responds remarkably well to chemotherapy.

Inflammatory breast cancer (IBC)

Inflammatory breast cancer is rare and aggressive. Its first signs are not a lump but redness, swelling and warmth — it can look like an infection.

Metastatic breast cancer (MBC)

Metastatic breast cancer means the cancer has spread beyond the breast to other organs. It is stage 4 — a chronic condition to manage, not a sentence.

Lobular carcinoma in situ (LCIS)

Despite the word carcinoma, LCIS is not cancer. It is a marker of increased future risk, usually managed with surveillance rather than surgery.

Other, rare breast cancer types

A small number of breast cancers are uncommon. Each has its own behaviour — and its own treatment path.

Breast cancer in men

Men can get breast cancer. It is rare — about 1% of cases — but the message is the same: a new lump or change deserves attention.

Breast cancer in young women

Breast cancer before age 40 is uncommon but real. It often presents differently, can be diagnosed later, and raises extra questions about fertility and genetics.

Breast cancer during pregnancy

Breast cancer during pregnancy is rare, but it happens. Modern care can treat it effectively while protecting both mother and baby.

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