Clinical Significance of Washing Cytology

Atsushi Nashimoto, Hiroshi Yabusaki, Yoshiaki Tsuchiya, Mitsuhiro Tsutsui, Otsuo Tanaka and Jyuei Sasaki

Division of Surgery, Niigata Cancer Center Hospital

Since 1988, Niigata Cancer Center Hospital has performed intraoperative peritoneal washing cytology (CY) of the Douglas pouch was in 673 patients (pts) with gastric cancer to diagnose latent peritoneal dissemination. Patients were classified as follows: 461 pts in P0, CY-; 40 pts in P0, CY+; 71 pts in P1; 44 pts in P2; and 57 pts in P3. Usually, Papanicolaou's staining method was used and immunocytochemical staining of CEA was carried out to make the definitive diagnosis. There were 155 pts (23.0%) in CY+, and the incidence of CY+ was 8.0% in P0, 46.5% in P1, 65.9% in P2 and 93.0% in P3, respectively. The 5-year survival rate was 55.9% in P0, CY-, 16.7% in P0, CY+,11.6% in P1, 2.7% in P2, and the survival curve of P0, CY+ was similar to that of P1. The survival of P0, CY+ pts and P1 pts who had undergone curative surgery was better than that of those with non-curative surgery, but there was no difference between curative and non-curative surgery in P2 and P3 pts. The positive rate of immunocytochemical staining of CEA was 66.7% in 24 pts of P0, CY+, and 28.6% in 28 pts of P+, CY-. CEA staining was useful for discriminating between cancer cells and benign reactive mesothelial cells. Prognostic factors were determined in 496 pts with advanced gastric cancer without liver metastasis by multivariate analysis. Curability of gastric resection, depth of tumor invasion, lymph node metastases, histological type and CY were independent prognostic factors. In conclusion, CY can be evaluated to detect latent peritoneal dissemination and can serve as an independent predictor of prognosis for pts with advanced gastric cancer.

Key words
washing cytology, immunocytochemical staining of CEA, advanced gastric carcinoma, peritoneal dissemination, prognostic factor

Reprint requests
Atsushi Nashimoto Division of Surgery, Niigata Cancer Center Hospital 2-15-3 Kawagishicho, Niigata, 951-8566 JAPAN

Accepted
November 13, 1998

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