Shreyaskumar R. Patel, MD: Trabectedin in Advanced, Invasive Myxoid Liposarcoma

How has the recent approval of trabectedin influenced treatment options for patients such as Michael?

Clearly, there has been an unmet need for newer treatments and additional treatments for this group of patients with soft tissue sarcomas. Liposarcomas and leiomyosarcomas happen to be two of the more common subsets of soft tissue sarcomas, and having another drug that’s commercially available and accessible to investigators and treating physicians around the country clearly adds something to the therapeutic armamentarium, specifically for this patient with mixoid liposarcoma where trabectedin seems to have some selective activity for this particular subset, as already documented in this patient. J

ust after the first couple of cycles, there seemed to be some clinical benefit and a radiographic response. So, having effective therapies that may not be curative but certainly can allow us to stretch the longevity out a little longer is very helpful. Remember that this is a group of tumors where survival resection of isolated metastatic lesions has been always incorporated as part of standard of care.

If there is some control of multifocal metastases with a systemic chemotherapeutic agent and the disease site is resectable, one would certainly incorporate consolidation of a response to systemic therapy with surgical resection to render the patient grossly free of disease which may be the first step to remaining free of disease for a little longer and potentially can impact on their longevity and lifespan.

CASE: Soft-Tissue Sarcoma Case 2

Michael C is a 59-year-old social worker from Los Angeles California; his medical history is notable for obesity, COPD, and mild hypertension.

• In January of 2014, he presents to his PCP with complaints of right lower leg pain of several weeks’ duration
• Physical exam was unremarkable except for swelling of the lower right calf; x-ray of the affected leg was negative for fracture
• MRI scan of the lower right calf showed a 20 cm well defined lobular mass arising between the gastrocnemius and soleus
• Biopsy of the mass showed myxoid liposarcoma with round cell component. Patient underwent en bloc resection of the tumor following preoperative radiotherapy
• Gross examination showed the tumor to be 10 × 8 × 15 cm with gelatinous brownish appearance

In September of 2014, Michael returns for follow up and his CT scan shows a 4 cm posterior mediastinal mass, and a 6 cm perinephric mass suspicious for metastatic disease. He initiates treatment with anthracycline and ifosfamide chemotherapy (6 cycles) for recurrent disease and shows a partial response.

• In May of 2015, he returns for follow up with intermittent chest and lower back pain; CT scan is consistent with progression of the mediastinal and perinephric masses, and bone scan shows new lesions occurring in the L2 and L3 lumbar vertebrae
• At recurrence, liver and renal function and CBC are within normal limits, and his ECOG performance status is 1
• He received treatment with trabectedin (1.5 mg/m2 24-hr infusion given every 3 week)
• At the 2nd cycle he develops febrile neutropenia (ANC< 500 cells/mm3) requiring hospitalization
• The oncologist reduces his trabectedin dose to 1.2 mg/m2; he continues therapy
• Within 1 week, he shows clinical improvement and CT scan shows slight improvement