Introduction & Objectives
Urinary Toxicity (UT) still represents a crucial issue in the Radiation Treatment (RT) of Prostate Cancer (PCa), owing to both the unchanged need over time, despite the widespread availability of modern IMRT techniques, to include the bladder neck/vesico-urethral anastomosis in the “high-dose” region and, more importantly, to the unpredictability of late events. Stool calprotectin has a well-established role in the monitoring of intestinal inflammation in patients (pts) with inflammatory bowel diseases. In this preliminary study, urinary calprotectine (UrCALPRO) was used as a potential marker of UT.
Material & Methods
Twenty pts were treated by RT with either radical, adjuvant or salvage intent. An IPSS (International Prostate Symptoms Score) questionnaire was filled-in by pts at baseline, at RT mid-point, end, and 90 days after RT end. With the same schedule, a urine sample was collected and diluted 1:10 in the Diluent Buffer, mixed by vortex (10 sec), and incubated at room temperature for 20 minutes. Levels of UrCALPRO were measured by means of fast immunochromatography assay (Calfast Reader) and the results expressed as mg/kg. The agreement between Calfast and subsequent ELISA assays was good.
An increase in UrCALPRO levels with respect to baseline (Fig. 1) was recorded at RT mid-point, end, and 3 months after RT conclusion (p=0.001, 0.004 and 0.11, respectively, ANOVA test). A similar trend was observed (Fig. 1) for the overall IPSS score: p=0.002, <0.0001 and 0.13, respectively. At Wilcoxon paired samples test, the association between the variations of UrCALPRO levels and IPSS scores (both the 8 single items and the overall sum score) with respect to baseline was always significant (p≤0.0003) at RT mid-point and end, and of borderline significance at 3 months (p=0.08-0.13).
Although preliminary, these findings suggest UrCALPRO as a potentially robust and easy to use tool for the timely assessment of RT-induced UT. If confirmed on a larger population, its role could be of potentially enormous importance in the timely detection and management of late events, often consequent to severe acute UT.
This study was supported by a grant from the Associazione Italiana Ricerca Cancro (Investigational Grant 14603) - ClinicalTrials.gov Identifier NCT02803086.