This patient support community is for discussions relating to advanced or metastatic prostate cancer, biopsy, bone scan, blood in urine or semen, benign prostatic hyperplasia (BPH), CT scan, cystoscopy, erectile dysfunction (ED), hormone therapy, incontinence, pain (abdomen, lower back or hip), PSA test, prostatitis, radiation therapy, rectal exam, recurrent cancer, screening, staging (tumor size, metastasis), transrectal ultrasound, watchful waiting, and urinary difficulty, burning, or urgency (leaking).
The pain in the back would probably be related more to a kidney problem than a prostate problem. The enlarged prostate is not a requisite to the formation of stones, but if the obstruction is significant, the stasis may be contributory.
BPH is pretty common, and while no absolute guides to tell who has cancer and who hasn't, among the commonly used guides to gauge the need for an invasive test (biopsy) would be the digital exam and the PSA.
Stay positive.