Rare Variants of Prostatic Carcinoma: The Management Approach from Multicentre Experience in Malaysia

Abstract

Objective

Up to 99% of prostate cancer were adenocarcinoma. Stromal prostate sarcoma only contributes 0.1% of primary prostate malignancy, whereas basaloid cell carcinoma is even rare prostatic neoplasm. We retrospectively evaluated the details of these rare prostatic malignancies, the management approaches, and the clinical outcomes of our case series.

Methods

A total of six cases with rare variants of prostate malignancy were managed and retrospectively reviewed to evaluate the symptoms at presentation, diagnostic methods, and staging protocol from two tertiary hospitals in Malaysia from 2019 to 2023, comprising four cases of prostate sarcoma and two cases of basaloid cell carcinoma of the prostate. Histopathological findings and treatment modality were analyzed. Overall survival was assessed.

Results:

In this study of six patients with rare prostatic malignancies, four had prostatic sarcoma (three had high rhabdomyosarcoma and one had high-grade unspecified sarcoma) and two had basaloid cell carcinoma (BCC). The median age at presentation was 48 years for prostatic sarcoma and 35 years for BCC. Clinical presentations included urinary obstruction (n=4), perineal pain (n=1), and gross hematuria (n=1). All patients underwent transrectal ultrasound-guided biopsy and comprehensive staging, including CT, MRI, and bone scans.

Treatment varied by disease type. Two patients with localized or locally advanced prostatic sarcoma received radical prostatectomy; one required postoperative chemoradiation due to positive surgical margins. The patient with locally advanced BCC underwent transurethral resection of the prostate (TURP) for symptom relief, followed by adjuvant radiotherapy (50 Gy) and androgen deprivation therapy (ADT). Systemic treatments included vincristine, Adriamycin, and cyclophosphamide for rhabdomyosarcoma, and cisplatin, Adriamycin, and ifosfamide for other sarcomas. The BCC patient received concurrent chemoradiotherapy with carboplatin, paclitaxel, and intensity-modulated radiotherapy (70 Gy). All advanced disease patients were treated with LHRH agonists.

The median follow-up was 24 months. Median survival was 43 months for localized or locally advanced cases and 2 months for metastatic cases. Among prostatic sarcoma patients, median survival was 37 months for rhabdomyosarcoma and 1 month for other sarcoma subtypes. BCC patients had a median survival of 14 months. All patients with localized or locally advanced prostate cancer survived till today, including one prostatic sarcoma patient with positive surgical margin post-prostatectomy with lung metastases during follow-up. Three patients with metastatic disease at presentation experienced death during follow-up.

Conclusion

Managing rare prostatic malignancies is complex and requires personalized approaches. Radical surgical resection remains the most effective treatment for locally advanced prostatic cancer disease. Systemic treatments offer limited benefits, especially for metastatic cases. Further research is needed to refine management strategies and improve patient outcomes.

Keywords

Sarcoma, Basaloid Cell Carcinoma, Prostate Cancer