Truncating mutations: an insight into the biology of urinary tract carcinomas?

A recent study by Arnoff and El-Deiry found that urothelial carcinomas of the bladder and upper tract as well as chromophobe renal cell carcinoma are more likely than other malignancies to harbor alterations in the gene, encoding for the cyclin-dependent kinase inhibitor p21, a major target of p53 regulatory pathways. Most of these mutations were truncating and thus presumably resulting in loss of p21 function. Herein, we discuss the prognostic and therapeutic implications of these findings.