|The following article features coverage from the Connective Tissue Oncology Society 2021 virtual meeting. Click here to read more of Cancer Therapy Advisor’s conference coverage.|
Myxoid liposarcomas that do not respond to radiotherapy (RT) are associated with poor outcomes such as metastatic disease and disease-related death, according to a retrospective study presented at the Connective Tissue Oncology Society (CTOS) 2021 Annual Meeting.
Myxoid liposarcomas are typically radiosensitive. However, it was unknown if the degree of response to RT had an association to outcomes. The aim of this study was to evaluate pre- and post-RT tumor volume and determine if the degree of shrinkage was associated with outcomes.
The retrospective study included 65 patients with nonretroperitoneal myxoid liposarcoma who underwent RT followed by surgical resection. Tumor volume was calculated by trained radiologists prior to and after RT. The mean follow-up was 8 years.
No change or no tumor growth occurred among 11% of patients, and 11% experienced up to a 25% volume reduction, 18% had a 25% to 50% reduction, 40% had a 50% to 75% reduction, and 20% had a 75% or greater reduction.
Overall, 84% of patients responded to RT and were considered to have radiosensitive tumors. Lack of radiosensitization was associated with shorter 10-year disease-specific survival of 29%, compared with 84% for radiosensitive tumors (P <.01). This translated to an increased risk of disease-specific death for patients with nonradiosensitive tumors (hazard ratio [HR], 4.54; P <.01).
Local recurrence was seen in 8% of patients and was not associated with radiosensitivity.
Metastatic disease was seen in 32% of patients and was significantly more likely to occur among patients with a nonradiosensitive tumor (HR, 3.47; P <.01).
The authors concluded that “radiosensitivity of this tumor translated into improved patient outcome; however, the results of the current series highlights that not all myxoid liposarcomas are radiosensitive and those that do not respond are higher risk for metastatic disease and subsequent death due to disease.”
Read more of Cancer Therapy Advisor’s coverage of CTOS 2021 by visiting the conference page.
Houdek MT, Mallett K, Robinson SI, et al. Lack of radiosensitivity predicts poor oncologic outcome in extremity myxoid liposarcoma. Presented at CTOS 2021; November 10-13, 2021. Abstract P202.