Mucinous Carcinoma

Mucinous carcinoma (MYOO-sin-us KAR-sih-NOH-muh) is a relatively rare type of cancer that starts in mucin, a protein in cells that line the inside of your organs. Mucin is a main part of mucus. It helps protect your body from intruders like bacteria, viruses and cancer cells.

In mucinous carcinoma, cancer cells in mucin multiply to form cancerous tumors. The cells also make large amounts of mucin that protect the tumors. Mucinous breast cancer is the most common form of the condition. But other forms may affect your colon, uterus or rectum.

Cancers linked to mucinous carcinoma

This condition represents between 3% and 15% of cancer types, including:

• Breast cancer
• Colon cancer
• Lung cancer
• Ovarian cancer
• Uterine cancer

Mucinous breast cancer is also known as colloid carcinoma. There are two types of this condition: pure and mixed mucinous carcinoma. In the pure type, mucinous cells are the only cancer cell type in the tumor. The mixed type develops when tumors contain mucinous cancer cells and other cancer cells.

Symptoms of mucinous carcinoma

Your symptoms will vary depending on the cancer’s location. For example, mucinous breast cancer may cause common breast cancer symptoms like:

• Lump in your breast
• Pain in your armpit or breast
• Changes in your breast, like its size and shape
• Nipple discharge
• Skin swelling, puckering or dimpling.

Mucinous colon or rectal cancer may cause symptoms like:

• Abdominal pain or cramping
• Blood in your stool or rectal bleeding
• Constipation and diarrhea
• Unexplained weight loss
• Weakness

Mucinous lung cancer symptoms may include:

• Chest pain
• Chronic cough
• Coughing up blood
• Hoarseness
• Shortness of breath

Some mucinous carcinomas are soft and grow very slowly. You may not have symptoms until a tumor grows large enough to affect the area where it started.

Potential causes

Experts don’t know the exact cause of mucinous carcinoma. But there are things that increase your risk. Those risk factors include:

• Age: Females ages 60 to 70 are more likely to develop mucinous breast cancer or ovarian cancer.
• Family history of cancer: Your risk is higher if close family members have cancer.
• Exposure to carcinogens: Alcohol, tobacco and UV radiation can lead to cancer.
• Genetic changes: Changes in certain genes may lead to different forms of this condition.

How doctors diagnose mucinous carcinoma

A healthcare provider will ask about your symptoms and your health history. They may do specific tests to check for cancer in your body, like:

• Imaging tests: You may have ultrasounds, MRI or CT scans. You may have a mammogram to check for breast cancer.
• Biopsy: A provider takes a small sample of tissue from the tumor. A medical pathologist will check the tissue for cancer.

How is mucinous carcinoma treated?

Treatment depends on the type of cancer, whether it spreads to other parts of your body and your overall health. Common cancer treatments include:

• Cancer surgery
• Chemotherapy
• Immunotherapy
• Radiation therapy
• Targeted therapy

Cancer symptoms and cancer treatment side effects can take a toll. Programs like cancer rehabilitation and palliative care may help.

When should I seek care?

In general, you should talk to a healthcare provider if you have general cancer symptoms, like feeling tired no matter how much rest you get or losing weight without trying. Having these symptoms doesn’t mean you have cancer, including mucinous carcinoma. Many issues cause them. Talking to a provider is the first step toward finding out what’s going on in your body.

What’s the survival rate for mucinous carcinoma?

Mucinous carcinoma survival rates vary. For example, an analysis of pure mucinous breast cancer cases shows 94% of women were cancer-free five years after treatment. Another study found 8 out of 10 women with early-stage ovarian cancer are alive five years after diagnosis. Early-stage cancer is cancer that’s caught before it has spread. 

Treatment may cure certain forms of this condition. But mucinous carcinoma can come back.

What’s the difference between adenocarcinoma and mucinous carcinoma?

Adenocarcinoma is cancer that starts in glands that line your organs. The glands release mucus. Mucinous carcinoma starts in the mucin, the protein that surrounds all cells.