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Outcomes after flap reconstruction for extremity soft tissue sarcoma: A caseecontrol study using propensity score analysis* S. Kang a,b, I. Han a,b,*, S. Kim c, Y.H. Lee a, M.B. Kim a, H.-S. Kim a,b a
Department of Orthopaedic Surgery, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea b Musculoskeletal Tumor Center, Seoul National University Cancer Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea c Department of Statistics, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 136-701, South Korea Accepted 8 May 2014 Available online - - -
Abstract Background: Because of the complexity of flap reconstruction and the magnitude of soft tissue defects, patients undergoing flap reconstruction for extremity soft tissue sarcoma (STS) may have increased morbidity and poor outcome compared with those undergoing primary closure. However, to examine the accurate impact of flap reconstruction on extremity STS patients, the potential bias by confounding factors should be minimized. Methods: We used propensity score analysis to match 37 patients who underwent flap reconstruction to 111 patients who underwent primary closure (1e3 ratio) based on patient and tumor characteristics at presentation. Treatment, functional, and oncologic outcomes were compared between the two groups. Results: Flap reconstruction group showed a lower Musculoskeletal Tumor Society functional score (P < 0.001), higher wound complication rate (P < 0.001), and longer hospital stay (P < 0.001); but had better local control (P ¼ 0.015) than the primary closure group. Although failing to reach the statistical significance, the flap group tended to secure a wider surgical margin than the primary closure group (P ¼ 0.051). Conclusions: Patients who underwent flap reconstruction had increased morbidity associated with flap reconstruction, but better local control. These findings may have implications for treating extremity STS patients. Ó 2014 Elsevier Ltd. All rights reserved. Keywords: Sarcoma; Extremity; Flap; Musculoskeletal Tumor Society Rating Scale; MSTS; Function
Introduction Limb-preserving surgery has become the standard of treatment for extremity soft tissue sarcoma (STS), as *
The location where the actual work was done: Department of Orthopaedic Surgery, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea. * Corresponding author. Department of Orthopaedic Surgery, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul 110-744, South Korea. Tel.: þ82 2 2072 0682; fax: þ82 2 764 2718. E-mail addresses:
[email protected] (S. Kang),
[email protected] (I. Han),
[email protected] (S. Kim),
[email protected] (Y.H. Lee),
[email protected] (M.B. Kim),
[email protected] (H.-S. Kim).
advances in imaging modalities and adjuvant therapy enable adequate margins to be achieved without the need for amputation.1,2 The limb-preserving approach often creates complex soft tissue defects that are vulnerable to wound healing problems. Flap reconstruction is the most complex method in the reconstructive ladder and is frequently used for these complex soft tissue defects.3e5 However, the inherent difficulties in flap reconstruction, such as vascular vulnerability and donor/ recipient site morbidity, may have an added impact on the potential unfavorable outcomes intrinsic to complex soft tissue defects in limb-preserving surgery for extremity STS.
0748-7983/$ - see front matter Ó 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.ejso.2014.05.004 Please cite this article in press as: Kang S, et al., Outcomes after flap reconstruction for extremity soft tissue sarcoma: A caseecontrol study using propensity score analysis, Eur J Surg Oncol (2014), http://dx.doi.org/10.1016/j.ejso.2014.05.004
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S. Kang et al. / EJSO xx (2014) 1e8
Because of the complexities of flap reconstruction and the magnitude of soft tissue defects, patients undergoing flap reconstruction for extremity STS are generally expected to have increased morbidity compared to patients undergoing primary closure. Moreover, prolonged wound healing, resulting in delayed adjuvant therapy, may have a detrimental impact on oncologic outcomes. A few studies have compared the characteristics and outcomes of patients receiving flap reconstruction versus primary wound closure for limb-preserving surgery for STS.6e8 However, to accurately examine the impact of flap reconstruction on treatment and outcomes of extremity STS patients, the potential bias introduced by confounding factors should be minimized. The propensity score is the conditional probability of a subject being in a particular group.9 Therefore, subjects in each group with equal propensity scores have the tendency of having nearly the same distributions of their covariates, thus bias-removing adjustment can be made.10 In this study, we used propensity score analysis to select a casematched control group among patients who underwent primary closure. We sought to compare the surgical, functional, and oncologic outcomes between patients undergoing flap reconstruction and those receiving primary wound closure for limb-preserving surgery for STS.
Patients and methods Patient selection The prospectively collected database of 544 patients who underwent limb-preserving STS resection of the extremity in our institute from January 2000 to November 2012 was retrospectively reviewed. Of the 544 patients, those with metastasis at initial presentation (n ¼ 56), age at the surgery
