Primary Squamous cell Carcinoma of the Prostate: A Novel Chemotherapy Regimen

Primary squamous cell carcinoma of the prostate is rare, accounting for 0.2% to 0.6% of all cases of prostate cancer.1 Squamous cell carcinoma of the prostate appears to be much more aggressive than adenocarcinoma, and afflicted patients have a dismal prognosis, with an average survival of about 6 months.1 We report on a patient with primary squamous cell carcinoma of the prostate that responded well to a combination of surgery, irradiation and novel adjuvant chemotherapy. At 18-month followup the patient was without evidence of recurrence. CASE REPORT A 71-year-old white man presented with painless hematuria. The patient denied any dysuria, frequency, urgency or hesitancy. He was noted to have undergone transurethral resection of the prostate for benign prostatic hyperplasia in 1990. Physical examination revealed a 2 firm symmetrical prostate with no palpable nodules. Routine urinalysis and excretory urography were normal. Cystourethroscopy showed an edematous friable injected mucosa in the prostatic urethra. The bladder was normal on examination. The patient underwent repeat transurethral prostatectomy, which yielded 30 gm. prostate tissue. Microscopic examination of the resected tissue demonstrated well to moderately well differentiated invasive squamous cell carcinoma (see figure). Clinical staging with chest x-ray; computerized tomography of the chest, abdomen and pelvis; and bone scan revealed no evidence of metastatic disease. The patient subsequently underwent radical retropubic prostatectomy with bilateral pelvic lymphadenectomy. Pathological examination of the prostate specimen showed moderately differentiated invasive squamous cell carcinoma. Surgical margins were positive at the membranous urethra. There was no evidence of involvement of the seminal vesicles, bladder or lymph nodes. The patient was administered chemotherapy consisting of 6 cycles of mitoxantrone (10 mg./m. 2 ) and cisplatin (60 mg./m. 2 ) followed by external beam radiotherapy (2,520 cGy.) to the prostate bed. He tolerated the chemotherapy and irradiation well. At 18-month followup he was without evidence of disease. DISCUSSION