The staging of gastric cancer is a broad and inconsistent concept. In general, there are two systems: gross and histologic staging. How is gastric cancer staged and what do the different staging mean? This article will introduce them.
Major staging of gastric cancer
Grand staging is the morphologic staging of a tumor based on its appearance to the naked eye. Depending on the stage, different systems are used for staging.
Early gastric cancer is classified as type I (elevated), type II (flat), and type III (sunken), with type II being further subdivided into type IIa (flat elevated), type IIb (flat), and type IIc (flat sunken).
Progressive gastric cancer The Borrmann staging is most commonly used and includes the following.
- Borrmann type I (polypoid), in which the tumor bulges mainly into the gastric lumen in a polypoid pattern;
- Borrmann type II (confined ulcer type), where the surface of the tumor is clearly ulcerated, with a dyke-like elevation of the ulcer margin and a more clearly defined cancer;
- Borrmann type III (infiltrative ulcer type), the surface of the tumor has obvious ulcers, but the ulcer margins are raised in a slope, and the ulcer margins and base of the ulcer grow deeper and infiltrate around;
- Borrmann type IV (diffuse infiltrative type), in which the tumor grows diffusely infiltrating into all layers of the gastric wall, without any obvious bulging mass or deep ulcer formation on the surface, and the gastric wall is thickened and hardened, resembling a capsule made of leather, so it is also called “leather capsule stomach” or “leather stomach”. “
Histotyping of gastric cancer
Histotyping is a judgment made by the pathologist on the morphology of tissue cells in resected specimens of gastric cancer when viewed under a microscope. The most commonly used are the Lauren typing and the World Health Organization (WHO) typing.
Lauren typing is divided into diffuse, intestinal, and mixed types.
WHO typing Most hospitals in China use the 1979 version, which is divided into the following types:
- Adenocarcinoma, including papillary, tubular, mucinous, and indolent cell carcinoma;
- Adenosquamous carcinoma
- Adenosquamous carcinoma;
- squamous carcinoma;
- carcinoid tumors (which have been redefined as neuroendocrine tumors);
- Undifferentiated carcinoma;
- Uncategorized carcinoma.
Some hospitals also use the 1990 version, which is divided into the following types:
- Adenocarcinoma, including papillary, tubular, mucinous, poorly adherent (including indolent cell carcinoma and its variants), and mixed adenocarcinoma;
- Adenosquamous carcinoma;
- Interstitial lymphoma (medullary carcinoma);
- hepatocellular adenocarcinoma;
- squamous cell carcinoma;
- Uncategorized carcinoma.
How does gross staging correlate with histotyping
There is a correlation between gross and tissue typing of gastric cancer. For example, the histotype of gastric cancer in gross staging Borrmann I and II is more often papillary or tubular adenocarcinoma, Borrmann III is more often hypofractionated adenocarcinoma and indolent cell carcinoma, and Borrmann IV is more often indolent cell carcinoma.
The significance of gastric cancer staging
The staging of gastric cancer is, to some extent, suggestive of outcome.
In terms of broad staging, early gastric cancer usually has a better outcome; among progressive gastric cancers, Borrmann type IV has the worst outcome, with a 5-year survival rate of about 10%, Borrmann type I has the best outcome, with a 5-year survival rate of about 60%, and Borrmann types II and III have 5-year survival rates of about 50% and 40%, respectively.
In terms of tissue staging, according to the Lauren staging, the intestinal type has the best outcome with a 5-year survival rate of about 50%, the diffuse gastric cancer has the worst outcome with a 5-year survival rate of about 40%, and the mixed type is in between. (Regardless of which version of WHO staging is used, the relatively good outcome is papillary carcinoma, with a 5-year survival rate of 32.9%, and the relatively poor outcome is undifferentiated carcinoma, with a 5-year survival rate of 20.5%.)
Gastric cancer staging is a very limited guide to treatment and is far less commonly used in the clinic than tumor staging, and only in isolated cases do physicians refer to pathologic type to change treatment decisions.
In summary, the staging system for gastric cancer is a heterogeneous one, which is suggestive of outcome but provides limited guidance for treatment. In clinical practice, physicians more often decide on treatment strategies for gastric cancer based on staging and other circumstances. (Contributed by Gao Peng, Department of Gastrointestinal Oncology, The First Hospital of China Medical University)