Adenocarcinoma

Adenocarcinoma is a type of cancer that begins in the glands lining your organs. It can affect many parts of your body, from your lungs and breasts to your stomach and colon, making it one of the most common forms of cancer people face today.

Table of contents

• What is Adenocarcinoma?
• Where Adenocarcinoma Occurs in the Body
• How Adenocarcinoma Can Spread
• Signs and Symptoms
• Causes and Risk Factors
• How Doctors Diagnose Adenocarcinoma
• Treatment Options
• Outlook and Survival

What is Adenocarcinoma?

Adenocarcinoma is a medical term that means gland cell cancer^[1]. It is a type of cancer that starts in the glands that line your organs. These glands help make important fluids your body needs, such as mucus and digestive juices^[1].

To understand adenocarcinoma, it helps to know about the tissue where it begins. Gland cells are found throughout your body. They help make the oil on your skin, the saliva in your mouth, and the mucus that helps food and waste move through your digestive system^[2]. When cells in these glands begin to change or grow out of control, tumors can form^[1].

Adenocarcinoma is actually the most common form of many types of cancer. For instance, 99% of prostate cancers, 85% of pancreatic cancers, and 40% of lung cancers are adenocarcinomas^[4]. Most breast cancers, colon cancers, and lung cancers are also adenocarcinomas^[2].

Where Adenocarcinoma Occurs in the Body

• Breast
• Colon/rectum
• Esophagus
• Lungs
• Pancreas
• Prostate
• Stomach

Because gland cells exist throughout the body, adenocarcinoma can develop in many different organs^[1]. The most common places where adenocarcinoma occurs include the breast, colon and rectum, esophagus (the tube that carries food from your mouth to your stomach), lungs, pancreas, prostate, and stomach^[1].

Each location has its own characteristics. For example, in the colon, adenocarcinoma often starts as a small polyp, which is a growth that’s usually harmless at first but can turn into cancer^[4]. In the breast, most breast cancers start in the glands where milk is made^[4]. In the lungs, adenocarcinoma is most often found in the outer part of the lungs and usually occurs in the lung periphery^[8].

How Adenocarcinoma Can Spread

Even though adenocarcinomas begin growing in the glands that line your organs, they can eventually spread to other parts of your body^[1]. This may include your brain, liver, lymph nodes, bone, or bone marrow^[1].

When adenocarcinoma spreads, doctors describe it in two main ways. Invasive adenocarcinoma refers to when cancer cells spread to surrounding tissues and nearby lymph nodes. Metastatic adenocarcinoma means cancer cells have broken away from the original tumor and traveled to distant parts of your body through your bloodstream or lymphatic system^[1].

Signs and Symptoms

Adenocarcinoma symptoms vary widely depending on which type you have and where the cancer is located^[1]. Some of the most common overlapping symptoms include pain near the affected organ, blood in bodily fluids (like your urine, stool, or saliva), changes in your appetite or weight, and bloating^[1].

Lung adenocarcinoma: The first symptom is usually a chronic cough. You may cough up saliva and mucus with small amounts of blood. Other symptoms may include shortness of breath, chest pain, wheezing, and hoarseness^[1].

Breast adenocarcinoma: Doctors usually find adenocarcinoma of the breast on a mammogram in the early stages before most symptoms start. When symptoms do appear, you may notice a change in a breast’s shape or size, discolored, flaky, dimpled or uneven skin on your breast or nipple, or bloody fluid leaking from your nipple^[1].

Colorectal adenocarcinoma: You may not notice any symptoms if the tumor hasn’t grown big enough. Even though colorectal adenocarcinoma typically causes bleeding in your stool, the amount may be too small to see. Other symptoms to watch for include abdominal pain, diarrhea, and constipation^[1].

Pancreatic adenocarcinoma: Most people don’t have symptoms until the late stages. The first warning signs are usually stomach pain and unintentional weight loss. Other symptoms include back pain, heartburn, nausea and vomiting, and stool that floats^[1].

Prostatic adenocarcinoma: Most of the time, there are no early symptoms. In the advanced stages, you may develop erectile dysfunction or notice that you urinate more than usual^[1].

Esophageal adenocarcinoma: Symptoms may include difficulty swallowing, indigestion, coughing, hoarseness, and pressure or burning in your chest^[1].

Gastric (stomach) adenocarcinoma: Symptoms may include feeling full after eating small amounts of food, difficulty swallowing, nausea, and indigestion^[1].

Causes and Risk Factors

Adenocarcinoma happens when cells in the glands that line your organs divide uncontrollably and start to spread^[1]. Experts aren’t always sure why some people develop adenocarcinoma, but there are several risk factors to consider.

Smoking or vaping is the primary cause of adenocarcinoma, especially for lung cancer^[8]. Tobacco use increases the risk of almost every type of cancer^[6]. Due to numerous cancer-causing substances present in tobacco smoke, primary or secondary exposure increases risk in proportion to the amount of exposure^[8].

Other risk factors vary by the organ involved. Age, race, family history, medication use, and lifestyle factors such as diet have been linked to certain forms of adenocarcinoma^[6]. Additional risk factors include occupational exposure to other agents such as silica, asbestos, radon, heavy metals, and diesel fumes, though these are less common^[8].

Genetic mutations also play a role. Changes in the p53 gene are the most frequent cause of tumor formation in non-small cell lung cancer (a category that includes adenocarcinoma) in 52% of cases^[8].

How Doctors Diagnose Adenocarcinoma

Diagnosis of adenocarcinoma begins with a medical history and physical examination^[6]. Your doctor will want to know about your symptoms and any risk factors you might have.

Lab work is usually completed and likely includes blood counts, a comprehensive metabolic panel, and urinalysis. Any lumps found are commonly biopsied, and specialized imaging techniques such as X-rays and computed tomography (CT) scans are used to determine the extent of the disease^[6].

A biopsy is particularly important for confirming adenocarcinoma. By staining the cells from a biopsy, a pathologist can determine whether the tumor is an adenocarcinoma or some other type of cancer^[5]. You might see the term adenocarcinoma in the results from a biopsy procedure to diagnose cancer, or it may be included in your health record after surgery to remove cancer^[2].

Treatment Options

Treatment options differ based on the adenocarcinoma type and disease progression, as well as factors such as your overall health and the extent of the disease^[6]. Treatment options include surgery, chemotherapy, and radiation therapy^[1].

Surgery may be used alone or combined with other treatments. Early-stage, localized disease may be treated by surgery alone (surgical removal of the tumor and surrounding tissue) or surgery with additional chemotherapy or radiation therapy afterward^[6].

Chemotherapy uses drugs to kill cancer cells or slow their growth. It is often combined with other treatments, especially for more advanced cases.

Radiation therapy uses high-energy rays to destroy cancer cells or keep them from growing.

Newer treatment approaches are also emerging. These include hormone therapy, stem cell transplantation, and immunotherapy, which targets specific proteins on the surfaces of cancer cells^[6]. You and your doctor will decide on the best approach based on where your tumors are growing and how long you’ve had them^[4].

Outlook and Survival

Survival rates vary depending on the location, stage, and type of adenocarcinoma^[1]. Without treatment, adenocarcinoma can be fatal^[6]. However, treatments can slow or stop the disease^[4].

For lung adenocarcinoma specifically, although incidence and mortality have declined since the 1980s, it remains the leading cause of cancer death in the United States^[8]. Despite new treatments, the 5-year survival is less than 12% to 15%^[8].

Early detection through routine physical examinations and avoidance of risk factors, such as smoking, are keys to prevention and improved outcomes^[6]. Advanced adenocarcinoma currently has no cure, but treatments can help manage the disease and improve quality of life^[6].