Prognostic significance of immunohistochemical micrometastases in node negative gastric cancer patients

BACKGROUND AND OBJECTIVES: The purpose of this study is to examine the prognostic significance of immunohistochemical (IHC) evidence of lymph node (LN) metastases in histologic node negative gastric cancer patients. METHODS: Retrospective review from 1981 to 1998 revealed 25 patients resected for T1-4N0M0 gastric and gastroesophageal (GE) junction adenocarcinoma. All cases were reviewed and histopathologic parameters were defined for each primary tumor. All LNs underwent IHC analysis with the epithelial marker CAM 5.2. Data are reported as median (range). RESULTS: The median number of LN resected was 7 (range 1-33). The median follow-up time was 25 months (range 4-195) with an overall 5-year survival rate of 55%. For patients with IHC evidence of LN micrometastasis (n = 9), the 5-year survival rate was significantly decreased (35%) compared to a 66% 5-year survival rate for IHC negative patients (n = 16, P = 0.05). CONCLUSIONS: The presence of IHC-detected LN micrometastases correlates with worse prognosis for patients with histologic node negative gastric cancer. IHC may be a useful additional staging modality in this subset of patients.