Tumor deposits in gastric cancer cannot be regarded as metastatic lymph nodes: A single-center retrospective study

In gastric cancer (GC), the significance of the number of tumor deposits (TDs) in prognostic evaluation remains a subject of debate. This study aims to investigate whether TDs can be equated to regional metastatic lymph nodes, potentially improving the accuracy of prognostic assessments in patients with TDs.

A retrospective analysis of clinicopathologic and follow-up data from patients who underwent radical gastrectomy at Yijishan Hospital of Wannan Medical College over a decade, from January 2012 to December 2021, was conducted. Patients were classified into TDs-negative and TDs-positive groups on the basis of the detection of TDs in their postoperative pathology reports.

The study included 4972 patients, with 575 (11.56 %) identified as having TDs. Among these, 524 TDs-positive patients were matched at a 1:1 ratio with 524 TDs-negative patients. Under the original TNM staging system, the chi-square (χ²) value was 58.234, with a C-index of 0.593. When TDs were classified as regional metastatic lymph nodes, the χ² value for the modified TNM staging system rose to 72.269, with an improved C-index of 0.609. Nevertheless, the prognosis within the TDs-positive subgroups IIIa, IIIb, and IIIc was still significantly worse than those in the TDs-negative subgroup, even when TDs were reclassified for staging purposes (P < 0.001).

Although treating TDs as regional metastatic lymph nodes can increase the accuracy of disease staging in GC patients, it does not necessarily convey the true prognostic value of TDs.