CORR Insights®: Is a Nomogram Able to Predict Postoperative Wound Complications in Localized Soft-tissue Sarcomas of the Extremity?

Where Are We Now?

In the current study, Bedi and colleagues [1] provided a novel method to predict an individual’s risk of postoperative wound complications in localized soft-tissue sarcomas of the extremity. After controlling for confounding variables, they found that increasing age, higher BMI, tumor location in the lower extremity, and use of neoadjuvant (preoperative) radiotherapy were associated with an increased likelihood that a wound complication would arise, which is consistent with several large retrospective studies [5, 10, 11].

Although the 5-year local control rates for soft-tissue sarcoma of the extremity could be 88% or higher [4, 8, 12], wound complications following limb sparing surgery combined with radiotherapy are as high as 30.2% [10], and complications of this sort can compromise limb function and diminish a patient’s quality of life. The other studies that have evaluated factors associated with wound complications after extremity soft-tissue sarcoma resection also found smoking, diabetes, flap reconstruction, and increasing tumor size might be associated with an increased risk of wound complications as well [5, 10, 11]. In general, these factors can be categorized into three types: Patient-related (elements like BMI and diabetes), tumor-related (tumor volume and location), and treatment-related (neoadjuvant radiotherapy and flap reconstruction).

Where Do We Need to Go?

While risk factors have been identified, providing an accurate prediction of wound complication for an individual patient is difficult because of the heterogeneity between different studies, especially when multiple variables interact. Because the number of potentially important risk factors is vast, and the ways in which they interact is complex, it’s not possible for a surgeon to anticipate with any precision the likelihood that a wound complication might arise. For that reason, predictive models like nomograms are essential; their utility is both prognostic (to inform patients about risk) but also potentially therapeutic: A well-crafted nomogram can point surgeons to steps they can take to mitigate the risk they identify. The nomogram in the current study may be valuable to prevent patients with extremity soft-tissue sarcoma from developing wound complications. Still, the data are preliminary, and external validation is needed before we can use it in practice.

Although the validation of this nomogram is confirmed based on the area under the curve of the receiver operating characteristic curve, the study results should be compared with those of other reports. However, some limitations make this comparison difficult. Prior studies [2, 10] on the risk factors of postoperative wound complication of extremity soft tissue sarcoma are retrospective analyses with small populations, lack uniform definitions, and report outcomes with high level of methodological variability. Lansu and colleagues [5], for example, defined wound complication of as any local complication of the surgical area requiring intervention, hospital readmission, and extension of the initial admission period, which differs from the definition in the current study [1]. Different selections of possible variables are another main problem. Some risk factors, including bone involvement, major vascular resection, and plastic reconstruction, have not been considered and should be included in future studies.

Satisfactory prophylactic management of high-risk patients is still in its infancy. Smoking, higher BMI, and a lower extremity or superficial tumor localization are prognostic factors for the development of wound complication after preoperative radiotherapy in multivariate analyses [10]. But because surgeons and patients have only a limited ability to modify those risk factors in advance of tumor surgery—which cannot easily be postponed for great lengths of time while a patient loses weight or tries to quit smoking—future studies should focus on treatment-related predictors such as, individualized preoperative radiotherapy regimens in combination with radiosensitizers, perioperative systemic therapies, and advanced wound healing strategies.

How Do We Get There?

Plastic surgery could be a consideration for patients with poor vascularization of the distal lower limb after preoperative radiotherapy. Flap reconstruction occasionally increases the complexity of surgery and leads to high complication rates. Many effective radiotherapy methods, such as photons or proton beam radiation therapy [6], which could decrease the amount of radiation to some normal tissues, have been introduced into clinical practice. Anti-angiogenic targeted drugs, such as pazopanib [3, 9] and regorafenib [7], are effective in advanced cases, and could be considered in neoadjuvant treatment for soft-tissue sarcomas. All these treatment advancements could potentially reduce or enhance the postoperative wound complication of rate of extremity soft-tissue sarcoma.

Therefore, it’s essential to establish a common language of extremity soft-tissue sarcomas at an international level (such as the International Society of Limb Salvage), including basic treatment procedures, definition of wound complications, and related risk factors. Then, the external validation of Bedi’s nomogram can be conducted prospectively in different regions of the world, such as the West and Asia-Pacific, or more specifically, in urban and rural areas.