If you have a progressive enlargement of prostate in spite of taking medications for the same or if you are having recurrent episodes of prostatitis it is better you get reevaluated by an experienced urologist. Because an increasing gland size inspire if medication warrants further intervention. And moreover recurrent phases of inflammation can lead to short term and  long term complications.

Enlarged prostate can be benign or malignant. Infection usually not cause cancer of prostate.