This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on August 25, 2023.
Mucinous adenocarcinoma is a rare type of cancer that begins in epithelial tissue, which covers all of the body’s external and internal surfaces. Mucinous means this cancer type is known for its mucus secretion. Adenocarcinoma is a type of cancer that begins in glandular tissue, and mucinous adenocarcinoma may occur in a variety of areas in the body.
This guide to mucinous adenocarcinoma is designed to help patients and their families learn the basic facts about mucinous adenocarcinoma, including:
Mucinous adenocarcinomas, also known as MACs, are a type of cancerous tumor that forms in the epithelial tissue. MAC tumors secrete mucus at a volume of more than 50 percent of the tumor.
This tumor type is often found in colorectal cancer, but it may also be found in any of the glandular organs, including the stomach, breast, ovary and lungs.
Mucinous adenocarcinoma is not yet fully understood. Large-scale research studies are needed to help doctors learn more about this disease.
It’s possible for several areas of the body to be affected by mucinous adenocarcinoma. Some common places it develops are listed below.
Colon and rectum: Colorectal mucinous adenocarcinomas are more commonly found in the beginning and middle parts of the colon and tend to be diagnosed at a more advanced stage.
Lungs: In rare cases, lung cancer may develop as mucinous adenocarcinoma.
Breast: Mucinous adenocarcinoma is an uncommon subtype of breast cancer. It’s further divided into two subtypes: pure type and mixed type.
Ovary: Ovarian cancer may develop as mucinous adenocarcinoma.
Gallbladder: In rare cases, mucinous adenocarcinoma may occur in gallbladder cancer. Because it’s difficult to diagnose, this cancer type may be challenging to treat.
Endometrial: Mucinous adenocarcinoma may occur in endometrial cancer, and it’s often diagnosed at an early stage.
If mucinous adenocarcinoma spreads to distant parts of the body, it’s referred to as metastasis. Metastatic cancer is sometimes referred to as stage 4 cancer. Cancer cells most commonly spread to the lungs, bones or liver, but every patient’s situation is different.
For patients who have metastatic mucinous adenocarcinoma, their care team will discuss treatment options.
A few differences distinguish mucinous adenocarcinoma from mucinous carcinoma. Mucinous carcinomas, also called colloid carcinomas, begin in the mucin, which is a protein that creates a barrier around all cells in the body.
On the other hand, mucinous adenocarcinoma begins in the mucous glands. Mucous glands produce mucous cells, which make up the mucous membrane that lines the body’s digestive tract. Adenocarcinoma is a subtype of carcinoma.
The symptoms of mucinous adenocarcinoma may vary based on where the cancer is located. Some patients may not have symptoms until their cancer has advanced.
Symptoms for each type of mucinous adenocarcinoma are detailed below.
Lung cancer:
Gallbladder:
Endometrial cancer:
The risk factors for mucinous carcinoma may vary based on the cancer’s location. Risk factors are listed below.
Colorectal cancer:
Breast cancer:
Gallbladder cancer:
The treatment options for mucinous adenocarcinoma vary based on several factors, including the cancer’s stage, location and grade, as well as the patient’s overall health. In addition to treating the cancer, treatments may be needed to remove excess mucus.
Treatment for mucinous adenocarcinoma may include the options below.
Surgery: For localized cancer, surgery may be used to remove the tumor.
Radiation therapy: Radiation therapy uses high-intensity, targeted X-rays to destroy cancer cells.
Chemotherapy: Chemotherapy uses medication to destroy cancer cells. It may be given as a standalone treatment or before surgery to help shrink the tumor. In some cases, a type of chemotherapy called hyperthermic intraperitoneal chemotherapy (HIPEC) may be used. This treatment uses heated chemotherapy to remove residual cancer cells.
Immunotherapy: During immunotherapy, medication helps the body’s immune system identify and destroy cancer cells.
Targeted therapy: Targeted therapy is similar to chemotherapy, but it avoids destroying healthy cells to help reduce treatment side effects.
Relatively few studies have been performed on mucinous adenocarcinoma survival, so researchers still have more to learn about the disease. One 2018 study in Scientific Reports identified the five-year survival rates as detailed below.
Localized MACs: When the cancer hadn’t spread outside the original affected organ, the five-year survival rate was 92.9 percent.
Regional MACs: When the cancer had spread beyond the original affected organ to nearby structures or tissue, the five-year survival rate was 64.5 percent.
Distant MACs: When the cancer had spread beyond the original affected organ to distant structures or tissue, the five-year survival rate was 21 percent.
However, survival rates are continuously improving as treatment options improve, and each patient’s circumstances are unique.
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National Cancer Institute (2020, November 10). Metastatic Cancer: When Cancer Spreads. https://www.cancer.gov/types/metastatic-cancer
Babaier A (2020). Mucinous Cancer of the Ovary: Overview and Current Status. Diagnostics (Basel). 10(1):52. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7168201/
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