Adenocarcinoma is the most common form of stomach cancer. It can cause digestive issues and abdominal pain. Its causes stem from genetic, dietary, and lifestyle factors, while treatment ranges from surgery to immunotherapy.
This article examines the causes, risk factors, and symptoms of adenocarcinoma. It details the stages and outlook of adenocarcinoma and discusses the diagnosis, treatment, and prevention of this condition.
According to the American Cancer Society (ACS), adenocarcinomas account for
As a
Infections can also cause adenocarcinoma. Scientists estimate that helicobacter pylori (H. pylori) infections cause between
Infections from the Epstein-Barr virus may cause between
Scientists have identified several risk factors for adenocarcinoma, including the following nutritional
- high salt intake
- low vitamin A and C consumption
- high intake of smoked or cured foods
- drinking contaminated water
- high caloric intake
Exposures to the following substances are also risk factors for adenocarcinoma:
- smoking
- radiation
- rubber, metal, and coal
Additionally, high body mass index and gastroesophageal reflux disease (GERD) can also increase the risk of adenocarcinoma.
Early stage adenocarcinomas do
- low appetite
- unintentional weight loss
- abdominal pain or discomfort
- feeling full quickly
- heartburn
- indigestion
- nausea
- vomiting
- abdominal swelling
- bloody vomit or stool
- tiredness or weakness
- jaundice, which indicates the cancer has spread to the liver
Anyone with these symptoms needs to speak with a doctor.
To diagnose adenocarcinoma, doctors may order the following tests:
- a medical history review
- a physical exam focusing on the abdomen
- upper endoscopy, which involves placing a thin, camera-mounted tube into the stomach via the esophagus, or food pipe
- a biopsy of unusual-looking cells
- imaging tests, including CT scans, PET scans, and MRI scans
Doctors may also order blood tests to see whether their patient is eligible for surgical treatment.
The staging system for adenocarcinoma is
Stages 0 and 1
| Cancer stage | Stage description |
|---|---|
| 0 | There are either atypical-looking cells in the stomach lining or cancer cells in the mucosa. |
| 1A | In stage 1A, the cancer has grown from the mucosa into deeper layers of the stomach lining. |
| 1B | Stage 1B is similar to 1A except that the cancer has spread to one or two nearby lymph nodes. Alternatively, the cancer has entered the muscularis propria, a large layer of the stomach lining that is deeper than the mucosa. |
Stage 2
| Cancer stage | Stage description |
|---|---|
| 2A | • The cancer has grown into deeper layers of the stomach lining and has spread to 3 to 6 lymph nodes. • The main tumor is growing in the muscularis propria layer and has spread to 1 or 2 nearby lymph nodes. • The main tumor is growing in the subserosa layer, which is deeper than the muscularis propria. |
| 2B | • The cancer has spread to deeper layers of the stomach lining and 7 to 15 nearby lymph nodes. • The main tumor is growing in the muscularis propria layer, and the cancer has spread to 3 to 6 nearby lymph nodes. • The main tumor is growing in the subserosa layer, and the cancer has spread to 1 to 2 nearby lymph nodes. • The cancer has grown through the stomach wall. |
Stages 3 and 4
| Cancer stage | Stage description |
|---|---|
| 3A | • The main tumor is growing in the muscularis propria layer, and the cancer has spread to 7 to 15 nearby lymph nodes. • The main tumor is growing in the subserosa layer, and the cancer has spread to 3 to 6 nearby lymph nodes. • The main tumor has grown through the stomach wall, and the cancer has spread to 1 to 6 nearby lymph nodes. • The main tumor has grown to nearby organs or tissues. |
| 3B | • The main tumor has grown into the deeper stomach lining, and the cancer has spread to at least 16 nearby lymph nodes. • The main tumor has grown into the subserosa layer or through the stomach wall, and the cancer has spread to 7 to 15 nearby lymph nodes. • The main tumor has grown through the stomach wall, and the cancer has spread to 1 or 2 nearby lymph nodes. • The main tumor affects nearby organs, and the cancer affects 3 to 6 nearby lymph nodes. |
| 3C | • The main tumor is in the subserosa layer or has grown through the stomach wall, and the cancer affects at least 16 nearby lymph nodes. • The main tumor affects nearby organs, and the cancer affects at least 7 nearby lymph nodes. |
| 4 | The cancer has spread to distant organs. |
According to the
- Endoscopic mucosal resection: Doctors use an endoscope to remove early stage cancers from the mucosa.
- Gastrectomy: This involves removing all or some of the stomach to remove as many cancer cells as possible.
- Radiation therapy: This uses external beams of radiation to kill cancer cells.
- Chemotherapy: This involves administering certain drugs, such as capecitabine and docetaxel, which travel through the body while killing cancer cells.
- Targeted therapy and immunotherapy: These drugs can target specific cancer cells or cell changes to reduce a cancer’s development.
Some treatments aim to cure the cancer or slow its growth, while others help individuals manage the symptoms. For instance, if stomach tumors are too large, doctors might place stents into an individual’s stomach. This can allow food to pass in and out of the stomach more easily.
Find out about preventing stomach cancer.
A 5-year relative survival rate helps show how likely a person with a condition is to be alive 5 years after diagnosis compared to someone without the condition.
The
| Cancer stage | Stage description | 5-year relative survival rate |
|---|---|---|
| Localized | The cancer has not spread outside of the stomach. | 75% |
| Regional | The cancer has spread to tissues or lymph nodes near the stomach. | 35% |
| Distant | The cancer has spread to distant body parts. | 7% |
The overall survival rate for adenocarcinoma is 36%.
Adenocarcinoma is the most common type of stomach cancer and often causes no symptoms in its earlier stages. Common causes and risk factors include a helicobacter pylori infection, dietary factors, and a high body mass index.
Several types of surgery, such as gastrectomy, can treat adenocarcinoma. Radiation and chemotherapy may also help.
The outlook for stomach cancer depends on how far the cancer has spread.