The Staging System for Gastric Cancer — Finding the Right Treatment Plan

“If cancer is found in the stomach, the next step for us as oncologists or surgeons … would be staging. What staging means is we ask ourselves is the tumor, the cancer, still confined only to the stomach or has it spread to other organs?” Dr. Sofia Pintova, a Gastrointestinal Medical Oncologist at Mount Sinai in New York City, tells SurvivorNet.

Clinical Staging — What Does TNM Mean?

Ideally, your oncologist should introduce the staging system and its importance early on in your cancer journey so that the results of early testing do not feel confusing or overwhelming to you and your family. Essentially, tests will be done to determine the patient’s TNM stage. Which tests depends on the patient and how their disease is presenting.

“Several tests that we usually do to identify [the disease stage] are what’s called radiology tests or imaging that could take the form of CT scans, PET scans, sometimes MRIs, whichever one is appropriate for an individual situation,” Dr. Pintova explains.

The TNM system, in the context of gastric cancer, stands for:

• T (Tumor): This indicates how deeply the tumor has invaded the layers of the stomach wall. Stages range from T0 to T4, with higher numbers representing deeper infiltration into the stomach layers. When needed, the “T stage” is best assessed with endoscopic ultrasound (EUS), which provides detailed images of these layers.
• N (Nodes): This stage reflects whether the cancer has spread to nearby (regional) lymph nodes. It ranges from N0 to N3, where higher values indicate more lymph nodes involved. A CT scan can help identify suspicious lymph nodes, hinting at potential cancer spread.
• M (Metastasis): This indicates whether cancer has spread to distant parts of the body. M0 means no distant metastasis, while M1 means there are metastases. A CT scan is often used to determine this aspect of staging.

After the TNM categories are established, the next step is to determine the clinical TNM stage, usually abbreviated as cTNM. The various possible combinations among these letters (i.e., T1N2M0, T1N1M0, and so on) will be translated into stages ranging from Stage 0 to Stage IVB, providing a clearer overview of the cancer’s extent.

Tailoring Treatment Accordingly

A precise diagnosis and accurate staging are essential before considering any targeted therapy for gastric cancer. Staging is crucial because it reveals how far the cancer has spread, helping doctors choose the most effective treatment. For this reason, staging should be completed as early as possible, as it forms the foundation for a well-informed, personalized treatment plan. Below, you will realize how treatment can vary according to the tumor’s stage.

Patients With Loco-regional Disease (Stage I to III)

For patients with loco-regional gastric cancer (stages I to III), there is potential for a cure, especially if they are healthy enough for surgery. If the cancer has invaded deeper layers of the stomach (stage T2 or higher) or if there’s a strong indication that nearby lymph nodes are involved, it’s important to consult a multidisciplinary team, or a care team that includes a variety of different specialists.

This team will work together to recommend the best treatment plan, which may involve going directly to surgery or starting with chemotherapy or chemoradiotherapy to improve the chances of success. This approach ensures that each patient receives the most effective treatment for their specific situation.

“Gastric cancer is a disease that’s commonly treated with chemotherapy. We know that for patients with very early stage disease that we call T1a or potentially T1b, meaning that there’s a small tumor that hasn’t really invaded through the gastric mucosa, the muscle layer, we can cut those out without needing surgery as long as there are no high risk features that we see when we review the surgical specimen of pathology,” Dr. Nicholas Hornstein, a Medical Oncologist at Northwell Cancer Institute in Manhattan, tells SurvivorNet.

Patients With Advanced Gastric Cancer

For patients with advanced gastric cancer that cannot be surgically removed or is classified as Stage IV, treatment generally focuses on improving quality of life and managing symptoms. This approach is known as palliative therapy, which is tailored based on each patient’s symptoms and overall health. Research shows that systemic treatments (like chemotherapy) can help extend survival and improve quality of life for these patients.

In some cases, about 5% of gastric cancers, the cancer invades a large portion of the stomach wall, causing it to become rigid and thickened—a condition known as linitis plastica. Unfortunately, linitis plastica has a very poor outlook, and many surgeons consider it a reason not to pursue surgery aimed at curing the disease, even if other factors might allow for surgery. In these situations, the focus remains on treatments that best support the patient’s well-being and comfort.

Treatment Planning Beyond Staging

Even if a patient has an early-stage, potentially curable cancer, sometimes they might not be able to receive certain treatments if their overall health status is poor. Doctors assess this using the ECOG scale (among other assessments), which rates patients based on their ability to perform daily activities, work, and care for themselves. This scale helps determine if patients are strong enough for treatments like surgery or intensive therapies.

It’s important to remember that the ECOG score can change over time, so regular reassessment is essential. This flexible approach allows doctors to make patient-centered decisions, adapting the treatment plan as the patient’s health and needs evolve.

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