Husband's elevated PSA level: What could it mean?

Hello, everyone. My husband, a few months ago, had a PSA of 6. His PCA prescribed antibiotics, which brought that number down to 4. He had a follow up appointment with a urologist today, scheduled a biopsy, and this doctor gave him a potential chance of cancer of 60/40%, and unfortunately, didn't seem supportive, or even explain other possibilities for his elevated PSA. I'm wondering if anyone has insight on this? My husband does not have a family history of prostrate cancer. Thank you, thank you!