Predictive factors with reference to low-risk of metastases in squamous cell carcinoma in the vulvar region

Among 122 patients operated upon for squamous cell carcinoma in the vulvar region 14 variables were investigated by a logistic regression analysis to determine their predictive value as to the presence/absence of metastases to the inguinal nodes. Factors of predictive value proved to be hyperchromasia, polymorphism, involvement of the clitoris, depth of invasion, and tumor size. On the basis of these variables, three different models of low-risk groups were set up. Model I comprised patients whose tumors showed slight hyperchromasia and did not involve the clitoris [metastatic rate: observed 0, estimated 2.1% (0.4-9.8%)]. Model II comprised patients whose tumors showed slight hyperchromasia, did not involve the clitoris, and measured less than 4 cm [metastatic rate: observed 0, estimated 1.6% (0.3-7.8%)]. Model III comprised patients whose tumors showed slight hyperchromasia, did not involve the clitoris, and had an invasion depth of less than or equal to 5 mm [metastatic rate: observed 0, estimated 1.3% (0.2-7.1%)].