Staging gastric carcinoma is not reliable when fewer than 10 lymph nodes are examined.
The researchers determined the number of nodes that must be examined in order to accurately stage gastric carcinoma, and published the findings in the latest issue of Cancer.
The study included all patients (n = 749) with TNM Stage I, II, or III resected gastric carcinoma, diagnosed between 1976 and 1996 in a well-defined French population.
A model of the relationship between the proportion of positive nodes and the number of examined nodes was performed.
This relationship was modeled to determine the number of nodes beyond which the proportion of node-positive tumors no longer changed.
The average number of examined lymph nodes was 8.4 per patient.
|Factors that influence prognosis:|
- Extension within gastric wall
- Age at diagnosis
- Number of examined nodes
More than 15 lymph nodes were examined in 18% of patients.
Under 10 examined nodes, the proportion of node-positive classified tumors significantly decreased with the number of examined nodes. Beyond this value, it remained stable.
The type of gastrectomy, and patient age, were the 2 factors independently associated with the resection of at least 10 nodes.
However, the diagnosis period was not associated.
After adjustment for the type of surgical resection, 3 variables were found to independently influence the prognosis of TNM Stage I or II tumors.
These were extension within the gastric wall (extension T3/T4 vs T1/T2; odds ratio [OR] = 2.05), age at diagnosis (age ≥ 70 years vs < 70 years; OR = 4.06), and the number of examined nodes (10 resected lymph nodes vs 0-9; OR = 0.57).
Dr Anne-Marie Bouvier, from Dijon, France, said on behalf of her colleagues, "The current study strongly suggests that staging is not reliable when fewer than 10 lymph nodes are examined."
"The number of examined lymph nodes should be used as a stratification criterion in clinical trials and as an adjustment variable in survival studies," she concluded.