e13088 Background: Soft tissue sarcomas (STS) are a rare group of heterogeneous tumors that may occur in the extremities. Little is known of their etiologies and only a handful putative risk factors have been identified. Studies as well as case reports have connected soft tissue tumors to events of physical trauma. There is mounting evidence of inflammation as both an initiator and promotor of tumorigenesis, as well progression. Moreover, as the physiological response of tissue repair and regeneration is mediated through inflammation, it is not unlikely that physical injury may cause and/or contribute to tumor initiation, promotion and/or progression, not least when the subsequent inflammation becomes chronic. Methods: We conducted a matched case control study in a total population in the South of Sweden 1988-2009, collecting 249 cases to examine the risk of STS of the extremities (STSE) following exposure to physical trauma such as accidental injury and/or surgery. Results: Having been exposed to surgery or injury from accidents to any part of the body both increased the risk of STSE, OR 2.1 (1.5 – 3) and 1.5 (1.1 – 2.1), respectively. Adjusting for potential confounders yielded ORs of 2.4 (1.6 – 3.6) and 1.4 (1.00 – 2.00). Surgery related odds ratios (SOR) varied with STSE histological subtype, from 1.2 to 4.2. UPS/MFH, Leiomyosarcoma and Liposarcoma showed significantly elevated SORs that were significantly greater than for remaining subtypes (P = 0.029). The accident related odds ratio (AOR) varied from 0.8 to 3.5, being significantly elevated for Leiomyo- and Liposarcoma, and the AOR of the two combined was significantly greater than remaining subtypes (P = 0.045). Analyzing surgery or accidental injury to a given part of the body and the subsequent STSE risk in the same location showed the SOR to be 4.13 (1.87 – 9.15) and the AOR was 2.29 (1.21 – 4.32). Conclusions: The population attributable risk of having had surgery was 37% (20 – 53%) and accidental injury was 13% (2 – 24%). Combined, the PAR was 43% (25 – 57%), indicating that tissue trauma may be an important contributing factor in sarcomagenesis of the extremities.
The Inter-Regional Epidemiological Study of Childhood Cancer (IRESCC): case control study of children with bone and soft tissue sarcomas