Comparison of N-acetylcysteine and mesna as uroprotectors with ifosfamide combination chemotherapy in refractory germ cell tumors

From January 1983 through August 1988, 318 consecutive patients with refractory germ cell neoplasms were treated with ifosfamide-containing combination chemotherapy. The patients received ifosfamide at 1.2 gm/m² day with cis-platin 20 mg/m² day for 5 days and etoposide 75 mg/m² day for 5 days or vinblastine 0.11 mg/kg on days 1 and 2 for each cycle. Of 277 evaluable patients, NAC was used as an uroprotector in the initial 86 patients while the latter 191 consecutive patients received mesna to reduce urothelial toxicity. Dosages of NAC was 2.0 gm po q 6 hr and for mesna 120 mg/m² IV push prior to ifosfamide and then 1200 mg/m²/day as continuous infusion of 5 consecutive days. All patients received 3.0 liters of normal saline per day. The number of courses of chemotherapy given in the two groups were similar. Twenty-four of the 86 patients (27.9%) receiving NAC developed hematuria (13 patients - grade 1, 4 patients - grade 2, and 7 patients - grade 3 toxicity). While 8 out of 191 (4.2%) mesna patients developed hematuria (6 - grade 1 and 2 - grade 3) (p<0.0001). The incidence of severity of renal toxicity was similar in the two groups. Ifosfamide dosage was reduced solely for urothelial toxicity in 11 patients receiving NAC compared with none of the patients receiving mesna (p<0.0001). Chemotherapy response was similar in the two groups. In conclusion, mesna provides better urothelial protection from ifosfamide-induced toxicity than NAC and allows better maintenance of the drug dosage.