Arylsulfatse B in colorectal cancer.

Arylsulfatase B activity has been determined in 24-hour urine samples from 243 patients with colorectal cancer. Elevated activity of the enzyme was obsereved in 172 out of 243 (71%) patients. Employing Dukes' modified classification of colorectal cancer, urine arylsulfatase B activity was elevated in Dukes' A lesions-1/8 (12%), Dukes' B lesions-24/43 (55%). Dukes' C lesions-89/111 (80%), and Dukes' D lesions-66/81 (82%). Arylsulfatase B activity in urine, when elevated, may be used to follow response to therapy since in those patients with elevated urine arylsulfatase B values who subsequently responded to therapy, the enzyme values became or approached normal. Urine arylsulfatase B activity also correlated with plasma carcinoembryonal antigen (CEA) as a diagnostic indicator of colorectal cancer in 33/46 (71%) patients. In contrast to the urinary findings, arylsulfatase B activity in tumor tissue was elevated in only 24% (27/110) of the specimens of colorectal cancer. It was also found that in a group of 55 patients treated with 5-fluorouracil, all of the 13 patients that showed objective response to therapy had activities of arylsulfatase B in the tumor tissue within the normal range for large bowel mucosa. Nevertheless, 22 to 26 of the 43 patients that did not respond also presented values in the normal range. The roles of lysosomal enzymes in colorectal cancer are discussed.