Effectiveness of Radiotherapy in Myxoid Sarcomas Is Associated With a Dense Vascular Pattern
- Department of Pathology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
- Department of Radiation Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
- Department of Experimental Therapy and Radiobiology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
- Department of Surgical Oncology, Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands)
Purpose: Surgery and adjuvant radiotherapy (RT) have long been the standard treatment for most deep-seated sarcomas; however, since the randomized trial from the National Cancer Institute of Canada, which described similar local control for pre- vs. postoperative RT, both modalities are now widely accepted. As a group, sarcomas are classified as radiation resistant. The subgroup of myxoid liposarcoma (MLS), a sarcoma with a typical vascular crow's feet pattern, is highly radiosensitive, but a mechanism for this phenomenon is unknown. Here we describe our results with preoperative RT and propose a mechanism explaining the high sensitivity based on the distinctive vascularization pattern of MLS. Methods and Materials: Between 2002 and 2006, 31 sarcoma patients, including 10 with MLS, underwent preoperative RT at our institute. Resected specimens were histologically evaluated, focusing on classification, grade, and vascularization patterns. Results: Twenty sarcomas showed more than 80% pathologic response after preoperative RT. A pathologic complete response was found in all 'pure' MLS specimens after preoperative RT (n = 8). There were no pathologic complete responses in the remaining sarcoma patients (n = 23), although 12 showed 80% to 90% pathologic response. In contrast to the remaining RT-resistant sarcomas, the highly responding specimens contained branching vasculature, partial thrombus formation and inflammation of medium sized arterioles, similar to the vascular changes in MLS. Conclusions: Both MLS and sarcomas with MLS-like vasculature are highly radiosensitive. Radiation sensitivity may be explained by changes in medium-sized arterioles, obstructing the specific crow's feet vascularization and inducing hypoxia with secondary tumor cell death.
- OSTI ID:
- 21172509
- Journal Information:
- International Journal of Radiation Oncology, Biology and Physics, Vol. 72, Issue 5; Other Information: DOI: 10.1016/j.ijrobp.2008.03.008; PII: S0360-3016(08)00417-3; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
- Country of Publication:
- United States
- Language:
- English
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