Metastatic prostate cancer with low PSA levels diagnosed after holmium laser enucleation of the prostate.

Holmium laser enucleation of the prostate is a widely accepted surgical treatment method for benign prostate hyperplasia, but its effect on prostate cancer remains unclear. In this study, we report the cases of two patients with metastatic prostate cancer diagnosed during follow-up after holmium laser enucleation of the prostate. Case 1 was a 74 year-old man who underwent holmium laser enucleation of the prostate. Prostate-specific antigen levels declined from 4.3 to 1.5 ng/mL at 1 month after surgery, but after 19 months, they increased to 6.6 ng/mL. Based on pathological and radiological findings, he was diagnosed as having prostate cancer, with Gleason score 5 + 4 with neuroendocrine differentiation, cT3bN1M1a. Case 2 was a 70 year-old man who also underwent holmium laser enucleation of the prostate. Prostate-specific antigen levels declined from 7.2 to 2.9 ng/mL at 6 months after surgery, but after 12 months, they increased to 12 ng/mL. Based on pathological and radiological findings, he was diagnosed as having prostate cancer, with Gleason score 4 + 5 with intraductal carcinoma of the prostate, cT3bN1M1a. This report suggests that advanced prostate cancer may be newly diagnosed after holmium laser enucleation of the prostate. Even if prostate cancer had not been demonstrated in the enucleated specimen, and postoperative PSA levels were below the standard values, physicians should regularly monitor prostate-specific antigen levels after holmium laser enucleation of the prostate, and further examination should be considered keeping in mind prostate cancer progression.