What is prostatic stromal sarcoma?

From the Guidelines

Prostatic stromal sarcoma is a rare and aggressive type of cancer that develops in the connective tissue (stroma) of the prostate gland, requiring a multidisciplinary approach for diagnosis and treatment, as outlined in the ESMO-EURACAN clinical practice guidelines 1.

Key Characteristics

• Accounts for less than 0.1% of all prostate malignancies
• Typically affects adult men, though it can occur at any age
• Arises from the specialized mesenchymal cells in the prostate rather than from the epithelial cells that cause the more common prostate adenocarcinoma
• Patients often present with urinary symptoms similar to benign prostatic hyperplasia, including difficulty urinating, increased frequency, or blood in the urine

Diagnosis and Treatment

• Diagnosis requires a biopsy with specific immunohistochemical staining to differentiate it from other prostate cancers
• Treatment generally involves surgical removal of the prostate (radical prostatectomy), often combined with radiation therapy and/or chemotherapy depending on the stage and grade of the tumor
• The best chance of cure is at the time of primary presentation, and an individualised management plan should be made, following discussion at a multidisciplinary sarcoma case conference on both imaging and pathological findings 1

Prognosis and Follow-up

• The prognosis is typically poor compared to common prostate cancer due to its aggressive nature and tendency to metastasize early to distant sites like the lungs, liver, and bones
• Regular follow-up imaging and examinations are essential after treatment due to high recurrence rates
• Management should be carried out in reference centres for sarcomas, with a multidisciplinary approach involving pathologists, radiologists, surgeons, radiation therapists, medical oncologists, and other specialists, as recommended by the ESMO-EURACAN clinical practice guidelines 1

From the Research

Definition and Classification

• Prostatic stromal sarcoma is an exceptionally rare urological malignancy, constituting less than 0.1% of all prostatic cancers 2, 3.
• It is a type of malignant mesenchymal tumor that originates in the stromal cells of the prostate gland.
• Stromal prostate tumors are classified into prostatic stromal tumor of uncertain malignant potential (STUMP) and prostatic stromal sarcoma (SS) based on criteria such as stromal cellularity, presence of mitotic figures, necrosis, and stromal overgrowth 4.

Clinical Presentation

• The main presenting symptom of prostatic stromal sarcoma is urinary retention secondary to bladder outlet obstruction 5.
• Patients may also experience nonspecific lower urinary tract symptoms, including dysuria and increased urinary frequency 2.
• Prostatic Specific Antigen (PSA) level can be normal in patients with prostatic stromal sarcoma 5.

Diagnosis and Treatment

• Diagnosis is typically made through a combination of digital rectal examination, imaging studies such as Magnetic Resonance Imaging (MRI) or Computed Tomography (CT), and histopathological examination of a biopsy specimen 2, 5.
• Treatment options include surgical excision, such as radical prostatectomy, and consideration of adjuvant therapies, including radiation therapy and chemotherapy 2, 3.
• The role of novel therapeutic strategies, including immunotherapy and targeted therapies, is also being explored in the treatment of metastatic sarcomas 2.