Stomach Cancer Awareness Month: Stomach Cancer Stages and Diagnosis

In the US, the number of new cases of stomach cancer has been dropping by about 1.5% each year over the last 10 years. However, the American Cancer Society estimates that stomach cancer accounts for about 1.5% of all new cancer diagnosed in the US each year (around 26,560 new cases in 2021 so far).

What is Stomach Cancer?

The body normally replenishes old or damaged cells by dividing and growing new ones. The growth of normal cells is highly regulated, and once enough replacement cells are produced to replace the old ones, the cells will stop dividing. A tumor occurs when cells keep growing uncontrollably as a result of a malfunction in the regulation system.

Stomach cancer, also known as gastric cancer, is a malignant tumor that starts in the cells of the stomach—malignant means that it is cancerous and can spread, or metastasize, to other parts of the body.

What Are the Symptoms of Stomach Cancer?

The most common symptoms of stomach cancer include:

●      Swallowing difficulties (dysphagia)

●      Weight loss

●      Digestive problems (dyspepsia) that persist

●      Small amounts of food leave you feeling full

●      Feeling or being sick

●      Tiredness associated with low red blood cells (anemia)

If you are experiencing unexpected weight loss, symptoms that are unusual for you, or that won’t go away, make an appointment with your doctor right away.

How Is Stomach Cancer Diagnosed?

A visit to your family doctor is the first step to diagnosis. They will ask you about any symptoms you have and perform a physical examination. Your doctor will use this information to refer you to a specialist or order lab tests to determine whether stomach cancer exists.

In addition to a physical examination, the following tests may be used to diagnose stomach cancer:

●      Upper Endoscopy:

○      An endoscopy is a medical procedure in which a doctor examines the inside of the body with a thin, lighted, flexible tube called a gastroscope or endoscope. During an endoscopy, a sample of tissue can be removed as a biopsy and examined for signs of cancer.

●      Biopsy:

○      The removal of sample tissues for testing. If any suspicious areas are detected during the upper endoscopy, a sample of tissue can be removed for testing using special tools. This sample is sent to a laboratory for analysis.

●      Imaging tests:

○      Imaging tests used to look for stomach cancer include CT scans, MRIs, and a special type of X-ray exam called a barium swallow. More advanced tests, such as positron emission tomography (PET) are used for determining the extent (stage) of stomach cancer.

●      Blood tests:

○      Blood tests to measure organ function can reveal whether your liver or any other organ in your body, is at risk of cancer.

●      Endoscopic ultrasound:

○      An endoscopic ultrasound involves passing a thin tube with a camera on the tip down your throat and into your stomach. Images of your stomach are taken using a special device. Stomach cancer can be detected using endoscopic ultrasound to determine how deeply it penetrates the stomach wall.

●      Exploratory surgery

○      Surgery may be recommended to check for signs that your cancer has spread beyond your stomach to your chest or abdomen. Exploratory surgery is usually performed laparoscopically. A surgeon inserts a special camera into your abdomen through several small incisions and transmits the images to a monitor in the operating room.

Stages of Stomach Cancer

Cancers are classified or staged according to the amount and location of cancer in the body at the time of diagnosis. Stages are used by your healthcare team to plan treatment and estimate your prognosis.

The most common staging system for stomach cancer is the TNM system which answers these questions:

●      Tumor (T): How far into the stomach wall has the primary tumor spread?

●      Node (N): Has the tumor spread to the lymph nodes?

●      Metastasis (M): How far has the cancer spread?

The stages of stomach cancer are 0 to 4, with 1 being the most advanced. The Roman numerals I, II, III, and IV are often used for stages 1 to 4. The higher the stage number, the more advanced the cancer is.

Stage 0 (carcinoma in situ)

This cancer only appears on the epithelium's surface. It has not spread to any of the stomach's layers. This stage reflects early cancer development (Tis, N0, M0).

Stage 1A (IA)

The cancer has grown into the inner layer of the stomach wall. No lymph nodes or other organs have been affected (T1, N0, M0).

Stage 1B (IB)

One of the following applies:

●      The cancer has spread to the inner layers of the stomach wall. One to two lymph nodes have been affected (T1, N1, M0), but not elsewhere.

●      It has grown into the outer muscle layers of the stomach wall. It has not spread to the lymph nodes or other organs (T2, N0, M0).

Stage 2A (IIA)

One of the following applies:

●      It has grown into the inner lining of the stomach. Three to 6 lymph nodes have been affected, but none elsewhere (T1, N2, M0).

●      It has spread into the outer layers of the stomach wall muscles. One to 2 lymph nodes are affected but not elsewhere (T2, N1, M0).

●      It has grown through several layers of muscle into the connective tissue outside the stomach. The tumor has not invaded the peritoneal lining or serosa or spread to the lymph nodes or surrounding organs (T3, N0, M0).

Stage 2B (IIB)

One of the following applies:

●      The cancer has spread to the inner layers of the stomach wall. Only 7 to 15 lymph nodes have been affected (T1, N3a, M0).

●      It has invaded the outer muscle layers of the stomach wall. Three to 6 lymph nodes have been affected, but not others (T2, N2, M0).

●      Cancer has spread through all layers of muscle into the connective tissue outside the stomach but not into the peritoneal lining or serosa. One or two lymph nodes have been affected but not others (T3, N1, M0).

●      There is cancer in every layer of muscle outside the stomach, even in the connective tissue. The tumor has invaded the peritoneal lining or serosa but has not spread to any lymph nodes or surrounding organs (T4a, N0, M0).

Stage 3A (IIIA)

One of the following applies:

●      The cancer has spread to the outer layers of the stomach wall. Seven to 15 lymph nodes are affected, but no other organs (T2, N3a, M0).

●      It has infiltrated every layer of muscle and connected tissue outside the stomach but has not penetrated the peritoneal lining or serosa. There are 3 to 6 lymph nodes affected, but no other organs are involved (T3, N2, M0).

●      It has penetrated the layers of muscles and entered the connective tissue outside the stomach. It has penetrated the peritoneal lining or serosa and spread to 1 to 2 lymph nodes, but no other organs (T4a, N1, M0).

●      It has spread through all layers of muscle into the connective tissue outside the stomach and has invaded nearby organs or structures. Neither lymph nodes nor distant organs have been affected (T4b, N0, M0).

Stage 3B (IIIB)

One of the following applies:

●      The cancer has invaded the inner layer of the stomach wall or the outer layer of the muscles that cover the stomach wall. Sixteen or more lymph nodes have been affected, but not distant parts of the body (T1 or T2, N3b, M0).

●      Cancer has spread through all layers of muscle into the connective tissue outside the stomach but has not invaded the peritoneal lining or serosa. Despite spreading to 7 to 15 lymph nodes, it hasn't invaded any organs around it (T3, N3a, M0).

●      The cancer has grown through the layers of muscle into the connective tissue outside the stomach and into the peritoneal lining or serosa. It has spread to 7 to 15 lymph nodes, but not elsewhere (T4a, N3a, M0).

●      The cancer has spread through the layers of muscle to the connective tissue outside the stomach and into nearby organs and structures. It may or may not have spread to 1 to 6 lymph nodes, but not to distant parts of the body (T4b, N1 or N2, M0).

Stage 3C (IIIC)

One of the following applies:

●      Cancerous cells have penetrated all layers of muscle and connective tissues outside the stomach and may have spread to the peritoneal lining. It has spread to 16 or more lymph nodes but not to distant organs (T3 or T4a, N3b, M0).

●      The cancer has penetrated all layers of muscle and is now in the connective tissue outside the stomach and invaded nearby organs or structures. It has spread to 7 or more lymph nodes, but not to other parts of the body (T4b, N3a, N3b, M0).

Stage 4 (IV)

The cancer has spread to other parts of the body (referred to as distant metastasis), including the lungs, bone, peritoneum, and omentum. This is also known as metastatic stomach cancer (any T, any N, M1).



Recurrent Cancer

Cancer that returns after treatment is referred to as recurrent cancer. This could be a localized recurrence, meaning that it has recurred in the same area. There is also the possibility of distant metastasis, meaning that it has returned to another part of the body. If cancer does return, further tests will be done to learn the extent of the recurrence. Often, these tests and scans are similar to those done at the time of diagnosis.

The Takeaway

November is Stomach Cancer Awareness Month. If you, or anyone in your family or friend group, are experiencing stomach-related issues that will not go away, it may be time to talk to your family doctor. To request an appointment at one of Northlake Gastroenterology’s locations, use the contact form on our website, or ask your family doctor.