Prognosis of potentially curable, completely resected gastric cancer is primarily determined by pathologic T and N staging criteria.
The optimal regional dissection extent during gastrectomy for gastric adenocarcinoma continues to be debated.
Dr Roderich Schwarz and colleagues created a gastric cancer data set through structured queries to the Surveillance, Epidemiology, and End Results database.
Relationships between the number of lymph nodes examined and survival were analyzed for the stage subgroups T1/2N0, T1/2N1, T3N0, and T3N1.
In every stage subgroup, overall survival was highly dependent on the number of lumph nodes examined.
|For every 10 extra lymph nodes dissected survival improved by 7% for T1/2N0|
|Journal of Clinical Oncology|
The team reported that multivariate prognostic variables in the T1/2N0 potentially curable resected gastric cancer subgroup were number of lymph nodes examined.
Other prognostic variables included age, race, sex, and tumor size.
The team confirmed a linear trend for superior survival based on more lymph nodes examined for all 4 stage subgroups.
Baseline model-predicted 5-year survival with only one lymph node examined was 56% for T1/2N0.
The team also noted that the baseline model-predicted 5-year survival was 35% for T1/2N1.
The 5-year survival predicted by the baseline model was 29% for T3N0, or 13% for T3N1.
For every 10 extra lymph nodes dissected, survival improved by 7% for T1/2N0, 6% for T1/2N1, 11% for T3N0, or 7% for T3N1.
The team noted that a cut-point analysis yielded the greatest survival difference at 10 lymph nodes examined.
However, a cut-point analysis continued to detect significantly superior survival differences for cut points at up to 40 lymph nodes.
The researchers found that the cut points were always in favor of more lymph nodes examined.
Dr Schwarz's team concludes, “Although the impact of stage migration versus improved regional disease control cannot be separated on basis of the available information, the data provide support in favor of extended lymphadenectomy during potentially curative gastrectomy for gastric cancer.”