Prospective validation of the association of local tumor stage and grade as a predictive factor for occult lymph node micrometastasis in patients with penile carcinoma and clinically negative inguinal lymph nodes.

PURPOSE: We prospectively validated the association of local tumor stage and grade as a predictive factor for occult lymph node micrometastasis in patients with penile carcinoma and clinically negative lymph nodes.

MATERIALS AND METHODS: In a retrospective study of 66 patients we demonstrated the predictive value of the association of local tumor stage and grade for occult micrometastasis, identifying 3 risk groups. A therapy strategy was designed according to these risk groups. A total of 37 consecutive patients were included in a prospective study in which the same criteria for risk group allocation and the same therapeutic recommendations were used as in the retrospective study.

RESULTS: In the prospective study we noted positive lymph nodes in 11% of stage T1, 63% of stages T2-3, 15% of grade 1, 67% of grade 2 and 75% of grade 3 cases. The incidence of positive nodes was 0% in the low, 83.3% in the high and 33.3% in the intermediate risk group. These rates were similar to those in the retrospective study with no significant difference.

CONCLUSIONS: The predictive value of the association of local tumor stage and grade for occult lymph node micrometastasis was validated in a prospective study. This factor allows the differentiation of 3 risk groups of patients with high reliability in the low and high risk groups. However, other prognostic factors are needed in the intermediate risk group to improve the prediction of lymph node involvement.