Abstract
Objective: Positive intraoperative peritoneal washing cytology (CY1) is regarded as an important prognostic factor in gastric cancer. Cases of gastric cancers with CY1 are classified as StageIV in the UICC-TNM system. However, the UICC supplement book avers that the prognostic significance of CY1 is overestimated. We compared the difference in prognostic significance of CY1 in the UICC-TNM and Japanese gastric cancer classification staging systems.
Study Design: We analyzed the prognostic significance of CY1 by the Kaplan-Meier method in 98 cases of T3-4 gastric cancer (CY1: 29 cases, CY0: 69 cases), classified according to the UICC-TNM system, at our hospital.
Results: CY1 cases had a significantly worse prognosis than CY0 cases. CY1 had an insignificant prognostic impact on the UICC-StageIV gastric cancer cases if the cases classified as StageIV only on account of CY1, i. e., UICC-StageIII+M1 (Cy+), are included. The UICC-StageIII+M1 (Cy+) cases had the same survivorship curve as the UICC-StageIII gastric cancer cases.
Conclusion: The prognostic significance of CY1 was strong in UICC-StageIV excluding UICC-StageIII+M1 (Cy+) cases classified as stageIV. The prognosis of UICC-StageIII+M1 (Cy+) cases was similar to that of the UICC-StageIII cases. This it is not suggested that the clinical approach to gastric cancer cases must not be determined only based on the results of intraoperative peritoneal washing cytology.