Is There A Chance Of Malignancy In Grade 2 Prostatomegaly And A PSA Level That Has Increased?

Hi, my father is 65 years old..he has been detected with grade 2 prostatomegalcy with 47 Cc and no median lobe..his Psa level has not gone down even after 1 month of medication which included first seven days (2 times a day) intravenous antibiotics. His Psa level one month back was 7.3 which now stands at 7.9..doctor has suggested biopsy ..is there any chance of malign cells