Adenocarcinoma: Types, Classification & Treatment

Adenocarcinoma is a malignant tumor that can affect the intestines, stomach, prostate, lungs, breast, uterus, and pancreas. It starts in glandular cells.

Even though they share the same name, adenocarcinomas are not all the same. How they progress depends on the organ involved, how fast the tumor grows, and the risk of metastasis.

For this reason, it is important to consult an oncologist promptly when a biopsy indicates adenocarcinoma. The specialist can complete the evaluation and recommend the most appropriate treatment plan without delay.

Main types

According to the National Cancer Institute (NCI), adenocarcinoma is cancer that forms in glandular tissue that lines certain internal organs and produces substances such as mucus and digestive fluids.

The main types of adenocarcinoma are:

1. Prostate adenocarcinoma

Prostate adenocarcinoma develops in glandular cells of the prostate and is more common in men over age 65.

While it often grows slowly over time, some types can grow quickly and behave aggressively. In these cases, it may spread to other organs and cause metastases.

Prostate adenocarcinoma can also be divided into subtypes, with acinar adenocarcinoma being the most common.

2. Lung adenocarcinoma

Lung adenocarcinoma is a cancer that affects glandular cells in the lungs. It is one of the most common types of lung cancer, accounting for about 60% of cases.

Although it is more common in people who smoke, it can also occur in people who have never smoked.

This type of tumor is often aggressive, so starting treatment as soon as it is identified is important.

3. Gastric adenocarcinoma

Gastric adenocarcinoma is a malignant tumor that develops in the cells of the stomach. It accounts for about 95% of tumors that affect the stomach and is more common in people over age 50.

Symptoms that may be associated with this tumor include abdominal pain, weight loss, nausea, and difficulty swallowing or digesting food.

4. Intestinal adenocarcinoma

Intestinal adenocarcinoma is one of the most common cancers in the general population. In many cases, this type of tumor responds well to treatment, especially when it is found early and has not spread to other organs.

For this reason, staying current with recommended screening tests is essential, particularly for individuals with a family history or other risk factors. The Centers for Disease Control and Prevention (CDC) advises most people to begin colorectal cancer screening around age 45, using stool-based tests such as fecal occult blood testing or a colonoscopy.

5. Pancreatic adenocarcinoma

Adenocarcinoma is the most common type of pancreatic cancer and is often quite aggressive.

It may grow without causing symptoms, and many cases are diagnosed at more advanced stages.

6. Breast adenocarcinoma

Most breast cancers are adenocarcinomas.

Early detection is important because it can improve treatment outcomes and increase the chance of a cure.

For that reason, appropriate screening matters, including visits with a gynecologist and a breast specialist, as well as regular mammograms.

Classification system

Based on its growth pattern, adenocarcinoma can be classified as:

• Adenocarcinoma in situ: the earliest stage, when the cancer is still limited to the tissue layer where it developed and has not invaded deeper layers, making it more likely to be curable;

• Invasive adenocarcinoma: when cancer cells extend into deeper tissue layers and may reach nearby organs or spread through the blood or lymphatic system, leading to metastasis;

• Well-differentiated adenocarcinoma: when cancer cells still resemble the original tissue and tend to grow more slowly;

• Poorly differentiated adenocarcinoma: when tumor cells look very different from the original tissue, which can suggest higher malignant potential and make treatment more challenging;

• Moderately differentiated adenocarcinoma: an intermediate category between well-differentiated and poorly differentiated.

To classify adenocarcinomas, a biopsy of the tumor tissue is needed. This allows the tissue to be examined under a microscope to better assess its features.

Treatment options

Treatment for adenocarcinoma depends on the tumor location, type, and classification. In general, options may include radiation therapy, chemotherapy, immunotherapy, targeted therapy, hormone therapy, and surgical removal of the tumor.

Treatment plans and prognosis can vary widely and are always individualized. It is important to discuss the options, possible consequences, and expected benefits with a clinician before starting treatment.

Is there a cure?

Adenocarcinoma can be cured in some cases, especially when it is diagnosed and treated early. The chance of cure also depends on the type of tumor identified.

Even in more advanced cases, there are treatments that can achieve excellent results.