Alveolar soft tissue sarcoma

Question:
15y old girl with no significant familial/personal history, referred to us after excisional surgery of a 2.5cm tumor arising from the external urethral meatus area. Initial pathological diagnosis: pecoma (?!), with microscopic involvement of surgical resection margins; available slides and blocks have been reviewed by our pathologists and Jaime Pratt has been also involved in the revised diagnosis following immunohystochemical analyses (excluding a clear cell or an amelanotyc melanoma). They conclude for an alveholar soft tissue sarcoma, which is a rare, malignant tumor with tendency to metastasize distantly, even after 10-20y, and with limited chemosensitivity (approximately 60% 5y OS, 40% 10y OS); it'd seem to be of poor value any score based on grade/necrosis to influence the treatment choice. The total body CT-PET scan is negative, as well as the gynecol OE (a urethrocystoscopy is scheduled next week). We have considered a re-intervention in order to wide resection margins, with particular attention to be paid in order to preserve continence; it'd seem to be not useful to perform any sentinel lymph node procedure (initially considered). Many thanks in advance for any suggestion with respect to the surgical/adjuvant management.

Stefano Greggi


 
Response # 1:
I have not heard of pecoma (wrong spelling?).   I would treat urethral alveolar soft tissue sarcoma with chemotherapy, external beam radiation (45 Gy) and HDR brachytherapy (3 Gy x 5). Alternative will be chemotherapy, and HDR brachytherapy (3 Gy x 12) similar to my regime for pediatric soft tissue sarcomas. The risk would be urethral fibrosis in the long term, but this can be treated with dilatation.  I feel it will be difficult/impossible to re-resect without affecting urinary continence.  Hope this helps.

Subir Nag

Response # 2:
I would favor a re-resection, preserving continence.  If that was not possible then I would consider interstitial HDR fractionated brachytherapy.

Kailash Narayan
 

Response # 3:
Dear all,
effectively very bad prognosis for this young lady
completely agree with re excision for clear margins
it seems fundamental (more than 2 cm, aggressive lesion, histological subtype) to discuss with radiotherapy a curie therapy in adjuvant setting
chemotherapy did not prove benefit for SAST in previous publication as for STS in general (adjuvant phase III from EORTC last asco meeting)
in case of early relapse, SARC 01 study (IGFR inhibitor from Roche) is open for this kind of patients
best regards

Isabelle Ray-Coquard