[Usefulness of new schemes to group Fuhrman grades in clinical practice for clear cell renal tumour].

OBJECTIVE

To evaluate if re-grading renal cell carcinoma (CRCC) in two or three-tiered grading schemes versus the traditional Fuhrman classification maintains the same prognostic value.

MATERIAL AND METHODS

A study of a cohort of 383 treated CRCC with radical or partial nephrectomy between 1990-2009 was made. We analyzed the demographic data, evolution and survival of these patients. An uropathologist reassigned the Fuhrman grades blindly to the first classification. In order to study if the prognostic value was maintained with the different classification, three Cox multivariate regression analysis were performed, classifying the variable of grade into four categories: (I-II-III-IV), into three (I+II-III-IV) and into two (I+II-III+IV). The explanatory variables were: age, gender, tumor size, study stage and grade. The response variables were progression-free survival (local-regional recurrence/metastasis) and cancer specific survival time.

RESULTS

The median overall survival was 125 months (95% CI: 92-159). In the three multivariate analyses carried out, the Fuhrman classification showed independent predictive value (p=:0.0001) compared to progression-free survival and cancer specific survival. The predictive power was maintained in the new classifications. In the three categories, the changing from grade I+II to III meant RR: 2.31 (p=0.0001) and from grade III to IV RR: 2.47 (p=0.0001) and in two-tiered classification an RR: 2.8 (p=0.001) was found when changing from I+II to III+IV.

CONCLUSIONS

Our results show that categorizing the Fuhrman grade into three or two-tiered grading schemes provide the same predictive accuracy on progressive free survival and cancer specific survival. Grades III and IV have different outcomes so that the three-tiered classification seems to be more appropriate to described the course of these patients.