[Clinical usefulness of the ImmunoCyt urinary test in the follow-up protocol of patients with urothelial neoplasms].

Objectives: The overall objective of this study was to carry out a prospective investigation of the usefulness of the IMMUNOCYT commercial kit in the follow-up of patients treated for bladder cancer and to evaluate its utility as a complement to urinary cytology and a possible tool for reducing the number of follow-up cystoscopies required.

Subjects And Methods: From September 2001 to December 2002, the ImmunoCyt test and urinary cytology were performed in urine simples from a total of 136 patients (115 with a history or suspicion of bladder cancer and 21 patients with other urological pathologies). Urine simples were fixed with an equal volume of 50% alcohol. Urinary cytology and the ImmunoCyt test were interpreted by a cytopathologist unacquainted with the result of the corresponding cytology and bladder biopsy report. Samples were staged and graded using the 1997 TNM classification of the UICC and the 1998 WHO/ISUP classification. Histopathological confirmation of lesions was available for 111 patients (81.6%).

Results: The gender distribution was 89% men and 11% women. Mean age was 71.68 years (range 27 to 98 years). Overall sensitivity and specificity were 77.9% and 92.3% for the ImmunoCyt test and 47.9% and 100% for urinary cytology, respectively. The positive (PPV) and negative predictive values (NPV) were 96.4% and 61.7%, respectively, for the ImmunoCyt test and 100% and 36.7% for cytology. In Ta and low-grade carcinomas, the sensitivity of the ImmunoCyt test was 70% (n=20) and 76.4% (n=34) respectively, whereas it was 25% (n=28) and 29.7% (n=37), respectively, for urinary cytology. The differences observed between the sensitivities of the ImmunoCyt test and cytology were statistically significant (X2 p<0.05) overall and for Ta and low-grade carcinomas. The sensitivity and specificity of the combination of both tests were 86.8% and 96.2%, respectively. The sensitivity of the combination of both tests for Ta and low-grade carcinomas was 80% (n=20) and 82.3% (n=34), respectively. The ImmunoCyt test was diagnostic in 36.2% of tumors overall.

Conclusions: In view of the results obtained, we decided to change our follow-up protocol to reduce the number of follow-up cystoscopies by 32.2% in the first 5 years of postoperative follow-up (in a cohort of 140 patients who undergo surgery annually). This benefits patients by reducing the number of urinary infections and iatrogenesis originated by follow-up cystoscopy. In addition, this 32.2% reduction in the number of cystoscopies in 5 years will yield a savings of approximately 35,560 EUR to the health care system in 5 years.