Risk of renal stone formation in patients treated with luteinising hormone-releasing hormone analogues for prostate cancer: importance of bone metabolism and urine calcium.

PURPOSE: To determine whether androgen blockade produces metabolic changes in urine and increases the risk of calculi after 1 year of treatment.

MATERIALS AND

METHODS

The study included 38 patients, from the period April 2015 to June 2016, diagnosed with locally advanced prostate cancer or lymph node metastasis, and with an indication of androgen blockade. Androgen blockade was started with luteinising hormone-releasing hormone (LHRH) analogues, and a blood specimen, a fasting urine and 24-h urine were collected at the time of inclusion, and then at 1 year of follow-up. A study was performed at baseline and at 1 year with imaging tests. An analysis of the variables was performed with a p ≤ 0.05 considered as statistically significant.

RESULTS

The mean age of the patients included in the study was 72.26 ± 6.75 years. As regards the biochemistry parameters, an increase in osteocalcin (from 16.28 ± 9.48 to 25.56 ± 12.09 ng/ml; p = 0.001) and an increase in β-crosslaps (from 0.419 ± 0.177 to 0.743 ± 0.268 ng/ml; p = 0.0001) were observed. In the urinary parameters, a significant increase was observed in the fasting calcium/creatinine ratio (from 0.08 ± 0.06 to 0.13 ± 0.06; p = 0.002) and in the 24-h calcium renal excretion (from 117.69 ± 66.92 to 169.42 ± 107.18 mg; p = 0.0001). Calculi formation was observed in 12 of the 38 patients included (31.6%), with a mean size of 3.33 ± 1.31 mm.

CONCLUSION

Treatment with LHRH analogues, as well as increasing the appearance of metabolic syndrome and speeding up the loss bone mineral density, causes an increase in fasting urine calcium.