This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science.
This page was updated on July 19, 2022.
Adenocarcinoma may develop almost anywhere in the human body, so it's important to understand what this cancer is, as well as the symptoms, risk factors, treatment options and survival rates.
Adenocarcinoma is a type of cancer that starts in glands that line the insides of the organs, which is why it can affect different body areas. Adenocarcinoma forms in glandular epithelial cells, which secrete mucus, digestive juices or other fluids. In some cases, adenocarcinoma spreads to other parts of the body, and at that point, it's called metastatic adenocarcinoma.
This article will cover:
Carcinoma is the most common type of cancer overall. It begins in epithelial cells, which are found in various linings in the body, such as the skin, the mucous membranes coating the inside of the gastrointestinal tract, and the tissue layers surrounding the inside or outside of organs.
Adenocarcinoma is considered a carcinoma subtype. It develops in organs or other internal structures. The other main subtype of carcinoma is squamous cell carcinoma, which usually occurs in the skin.
Glands help the body function properly and keep organs moist. If glandular cells begin growing out of control, spurred by mutations that occur in the body’s DNA replication process, they may form tumors. Some tumors in glandular cells are not cancerous. They’re called adenomas. The malignant tumors are adenocarcinomas, which overtake healthy tissue inside an organ and may spread to other parts of the body.
Adenocarcinomas are generally first seen as a thickened, plaque-like white mucous membrane, according to the National Cancer Institute. They often spread easily through the soft tissue where they occur.
Many organs have glandular cells. Adenocarcinoma is often identified by its specific type, such as exocrine cancer in the pancreas, invasive ductal carcinoma in the breast or endometrial cancer in the uterus. Adenocarcinoma is most prevalent in the cancers below.
Lung cancer: Non-small cell lung cancer accounts for 80 percent of lung cancers, and adenocarcinoma of the lung is the most common type.
Prostate cancer: Cancer that forms in the prostate gland is typically a prostate adenocarcinoma, which accounts for 99 percent of all prostate cancers.
Pancreatic cancer: Pancreatic adenocarcinomas form in the pancreas ducts and are the most common type of pancreatic cancer.
Esophageal cancer: Cancer that forms in the glandular cells of the esophagus is known as adenocarcinoma. Esophageal adenocarcinoma is the most common type of esophageal cancer.
Colorectal cancer: Cancer that develops in the intestinal gland cells that line the inside of the colon and/or rectum is an adenocarcinoma. It makes up 95 percent of colon and rectal cancers.
Breast cancer: The most common form of breast cancer, invasive ductal carcinoma, is an adenocarcinoma.
Stomach cancer: More than 90 percent of stomach cancer (gastric cancer) cases are gastric adenocarcinomas, either intestinal or diffuse.
It’s possible for adenocarcinoma to appear in the brain, usually from cancer that has metastasized from other areas of the body. Adenocarcinoma may also develop elsewhere in the body.
With so many different types of cancer under the heading of adenocarcinoma—and the metastases that are possible—there are many different risk factors and symptoms, depending on the specific disease.
The exact cause of adenocarcinoma is not known, but smoking is one risk factor that appears to apply to all adenocarcinomas.
Risk factors for adenocarcinoma vary depending on cancer type. It’s important to remember that risk factors don’t guarantee a cancer diagnosis; rather, they increase the odds of developing it. Some risk factors may be something patients are able to change, such as lifestyle factors.
Lung adenocarcinoma is a type of non-small cell lung cancer (NSCLC) and the primary cause of death from cancer in the United States. As with other types of lung cancer, smoking is the biggest risk factor.
Other risk factors include:
Some studies have found that taking beta carotene supplements and being exposed to arsenic in drinking water may increase lung cancer risk. Using talc or talcum powder and smoking marijuana or e-cigarettes are considered unproven risk factors.
The risk of prostate cancer increases after age 50, with the majority of cases found in men older than 65, according to the American Cancer Society (ACS). Men of African ancestry are at increased risk.
A family history of the disease or inherited genetic mutations—such as the BRCA1 or BRCA2 genes—are associated risk factors, as is hereditary non-polyposis colorectal cancer (HNPCC), also known as Lynch syndrome.
The risk of pancreatic cancer rises with age, with most cases found in patients older than 65. Men develop pancreatic cancer more often than women, and race also plays a role, with African-Americans at a slightly higher risk.
Other risk factors include:
Men are more likely than women to develop esophageal cancer. As with some other cancers, risk increases with age. The majority of cases are found in patients older than 55, according to the ACS.
Other risk factors include:
The greatest risk factors for colorectal cancer are age, gender and family history. Men are more likely than women to develop the disease.
Other risk factors include:
A family history of the disease as well as inherited genetic mutations (such as BRCA1 and BRCA2) raise the risk of breast cancer. Familial inheritance accounts for 5 percent to 10 percent of breast cancers, according to the U.S. Centers for Disease Control and Prevention.
Other risk factors include:
Women who have taken hormone replacement therapy or birth control, have never carried a full-term pregnancy or had their first child after age 30, or didn’t breastfeed, are at increased risk—as are women who took the drug diethylstilbestrol (DES), or whose mothers took the drug.
Men are more likely to develop stomach cancer, and risk increases with age. The majority of patients are diagnosed over the age of 60. According to the American Cancer Society, stomach cancer is more often found among Hispanic-Americans, African Americans, Native Americans and Asian/Pacific Islanders than among whites in the United States.
Other factors include:
The following inherited conditions may also increase stomach cancer risk:
The symptoms of adenocarcinoma depend on the location of the cancer.
Early symptoms of adenocarcinoma of the lung include:
Signs of adenocarcinoma of the prostate include:
Symptoms of adenocarcinoma of the pancreas often don’t occur until the disease has progressed. When this occurs, a patient may experience:
Symptoms of adenocarcinoma of the esophagus include:
Symptoms of adenocarcinoma of the colon or rectum include:
Symptoms of adenocarcinoma of the breast include:
Symptoms of adenocarcinoma of the stomach include:
Because adenocarcinoma may develop in so many different areas of the body, the type of diagnostic tests used also vary.
Breast cancer is frequently found in its early stages during mammogram screenings. Prostate cancers are often detected through a prostate-specific antigen (PSA) blood test or a digital rectal exam (DRE). A colonoscopy may be used for diagnosing colon cancer, while bronchoscopy may be used to detect adenocarcinoma of the lung.
In general, the types of tests that are performed may include:
Biopsy: This procedure is used to remove a sample of abnormal tissue from the body. A pathologist will then examine the tissue under a microscope to see whether cancer is present. A biopsy may also be used to determine whether a cancer originated at the site of the biopsy or if it’s metastatic, meaning it developed in another part of the body.
CT scan: A computed tomography scan is an imaging procedure that takes detailed, three-dimensional X-ray pictures of abnormal tissue in the body. CT scans may also be used to determine how adenocarcinoma is responding to treatment.
MRI: Magnetic resonance imaging uses radiofrequency waves to create detailed cross-sectional images of different parts of the body.
Blood tests: These lab tests are used to detect specific chemicals in the blood that may be related to different adenocarcinomas.
When a biopsy sample is sent to a laboratory for analysis, a pathologist examines the specimen under a microscope. Pathologists are doctors who are experts at diagnosing disease. One of the jobs of a cancer pathologist is to assess how the cancer cells appear microscopically. Cancer cells may look abnormal or similar to healthy cells.
Differentiation refers to the degree of similarity or difference between the cancer cells and healthy cells.
Doctors sometimes assign a grade to a tumor based on this cell differentiation. Typically, adenocarcinoma tumors are given one of three grades:
Low grade, which means the cells are well differentiated adenocarcinoma
Intermediate grade, which means the cells are moderately differentiated adenocarcinoma
High grade, which means the cells are poorly differentiated adenocarcinoma
Determining a cancer’s grade is an essential part of the diagnostic process for some adenocarcinomas, including those that affect the breast, kidney and prostate. For these types of cancer, the differentiation of cells is often highly related to their growth speed, and it may help inform a patient’s prognosis and treatment. However, for other cancers, such as adenocarcinoma of the lung, differentiation is usually not an accurate method of predicting the outcome or likelihood that the cancer will spread.
Following an adenocarcinoma diagnosis, the care team will stage the cancer, which is helpful when creating a treatment plan. The guidelines around determining the adenocarcinoma stages may differ depending on where the cancer is located, but the following guidance may help patients understand the general adenocarcinoma stages.
Stage 0 adenocarcinoma: The cancer remains where it started and hasn't grown into nearby tissue.
Stage 1 adenocarcinoma: The cancer is small and contained to local tissue, and has not spread to nearby lymph nodes or to other organs.
Stage 2 adenocarcinoma: The cancer cells have more deeply spread into nearby tissue and possibly into local lymph nodes, but not to distant organs.
Stage 3 adenocarcinoma: The tumor may be larger than in stage 2, or the cancer cells may be observed in deeper tissue or lymph nodes.
Stage 4 adenocarcinoma: The cancer has spread to other body areas further away from the original location. Adenocarcinoma stage 4 is also referred to as metastatic adenocarcinoma.
Treatment for adenocarcinoma also varies depending on where it grows in the body. Treatments may include:
Surgery: Often the first line of treatment for adenocarcinoma, surgery is used to remove the cancerous glandular tissue and some surrounding tissue. If possible, minimally invasive surgical procedures may be used to help reduce healing time and the risk of post-surgical infection.
Chemotherapy: Chemotherapy uses drugs to kill cancer cells. Chemo drugs may be used throughout the body or in a specific area.
Radiation therapy: Often used in combination with surgery and/or chemotherapy, advanced radiation therapies use image guidance before and during treatment to target adenocarcinoma tumors and spare healthy tissues and surrounding organs.
Targeted therapy: Unlike chemotherapy, which kills healthy and cancerous cells, this treatment targets cancer cells directly. The therapy is designed to attack genetic features that regulate cells’ growth and division.
Immunotherapy: Rather than attack cancer cells directly, immunotherapy alerts the body’s immune system to the presence of the abnormal cells. That, in turn, triggers the body’s own immune response to attack the cancer.Adenocarcinoma describes the type of cells in which the cancer begins (epithelial cells), not where in the body the cancer forms. As a result, the survival rate of adenocarcinoma is highly dependent on the patient’s circumstances, including the cancer’s location and stage, and whether or not other illnesses are present.
Usually, doctors use a five-year relative survival rate to communicate estimated outcomes to patients. A five-year relative survival rate shows the likelihood that a person with a specific type and stage of cancer may live for at least five years after the diagnosis, compared with people who don't have cancer. Doctors can sometimes provide three survival rates for each cancer type:
Data from past patients is used to predict these average relative survival rates. They’re usually calculated by the cancer’s location and stage, but not by specific subtype, such as adenocarcinoma. However, the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) Program provides some adenocarcinoma-specific survival statistics for certain cancer stages based on the years 2012 to 2018, such as:
Adenocarcinoma of the lung and bronchus: The five-year relative survival rate of lung adenocarcinoma is 71.9 percent for localized cases, 45.1 percent for regional cases and 9.5 percent for distant cases. The overall five-year relative survival rate for adenocarcinoma of the lung and bronchus is 29.8 percent, according to SEER.
Adenocarcinoma of the esophagus: The five-year relative survival rate for esophageal adenocarcinoma is 51.9 percent for localized cases, 26.9 percent for regional cases and 5.5 percent for distant cases. The overall five-year relative survival rate for adenocarcinoma of the esophagus is 21.8 percent, according to SEER.
It’s important to recognize that these numbers are just estimates, based on averages rather than individuals. The patient's care team will be able to provide him or her with a more specific prognosis based on the type, stage and location of the cancer.
Adenocarcinoma that spreads to another part of the body is considered metastatic adenocarcinoma, which is also called stage 4 adenocarcinoma. When cancer spreads to another part of the body, it’s still named for the location of origin—so breast cancer that’s spread to the lung is still called breast cancer, or metastatic breast cancer of the lung, not lung cancer.
Cancer cells sometimes spread when they break off from the original tumor. They may travel through the bloodstream or lymph system to other parts of the body. Most of these cells die along the way, but some survive and find areas to grow. In the case of lung adenocarcinoma, cancer cells may also spread through airways in the lungs. Researchers are still learning about this type of spread, called aerogenous metastasis.
Since cancer often spreads through the bloodstream or lymph system, cancer cells are more likely to spread to the organ or set of lymph nodes “downstream” from where the primary cancer started. Breast cancer, for example, tends to spread to underarm lymph nodes. Metastatic adenocarcinomas most commonly spread to the bones, lungs, liver and/or lymph nodes, but they also may spread to other areas of the body.
In addition to nearby lymph nodes, certain types of adenocarcinomas are more likely to spread to these areas:
Adenocarcinomas may be more likely to spread if the cancer cells are high-grade (also called poorly differentiated), which means they look different from normal cells under a microscope. High-grade cancers are aggressive and more likely to grow and become metastatic than low-grade cancers.