Background/aims: Primary signet-ring cell colorectal carcinoma is rare and has been reported to have an extremely poor prognosis. The purpose of the present study was to define the characteristics of this cancer.
Methodology: Clinicopathological features were analyzed in 154 Japanese patients.
Results: The mean age at diagnosis was 54.3 years. The most common tumor site was the rectum (32.9%). Frequent type of the tumor was scirrhous in 45.8%, ulcerated in 34.5%. Lymph node metastasis was found in 77.4% and synchronous peritoneal dissemination was seen in 38.7%, while synchronous liver metastasis was only detected in 2.9%. Most patients (78.2%) were in stages III or IV. The overall median survival time was 12.7 months and the 5-year survival rate was 9.4%. For stage II patients, the median survival time and 5-year survival rate were 17.4 months and 14.3%, respectively, while the median survival time was 15.4 months in stage III and 7.9 months in stage IV. The 5-year survival rate of patients with T2 disease was 75.0%, while patients with T3 or T4 had survival rates of 5.1% and 0%, respectively.
Conclusions: Since the prognosis of primary signet-ring cell colorectal carcinoma is extremely poor, early diagnosis and aggressive treatment strategy are necessary.