Postoperative complications and oncologic outcomes after multimodal therapy of localized high risk soft tissue sarcoma

Abstract

Background: Standard therapy for localized high-risk soft tissue sarcoma includes surgical resection and neoadjuvant or adjuvant radiation therapy (± chemotherapy and locoregional hyperthermia). No difference in oncologic outcomes for patients treated with neoadjuvant and adjuvant radiation therapy was reported, whereas side effect profiles differ. The aim of this analysis was to analyse oncologic outcomes and postoperative complications in patients treated with multimodal treatment.

Methods: Oncologic outcomes and major wound complications (MWC, subclassified as wound healing disorder, infection, abscess, fistula, seroma and hematoma) were evaluated in 74 patients with localized high-risk soft tissue sarcoma of extremities and trunk undergoing multimodal treatment, and also separately for the subgroup of lower extremity tumors. Clinical factors and treatment modalities (especially neoadjuvant vs. adjuvant radiotherapy) were evaluated regarding their prognostic value and impact on postoperative wound complications.

Results: Oncologic outcomes were dependent on number of high risk features (tumor size, depth to superficial fascia and grading), but not on therapy sequencing (however with higher risk patients in the neoadjuvant group). Different risk factors influenced different subclasses of wound healing complications. Slightly higher MWC-rates were observed in patients treated with neoadjuvant therapy, compared to adjuvant radiotherapy, although only with a trend to statistical significance (31.8% vs. 13.3%, p = 0.059). However, except for wound infections, no significant difference for other subclasses of postoperative complications was observed between neoadjuvant and adjuvant therapy. Diabetes was confirmed as a major risk factor for immune-related wound complications.

Conclusion: Rates of major wound complications in this cohort are comparable to published data, higher rates of wound infections were observed after neoadjuvant radiotherapy. Tumor localization, patient age and diabetes seem to be major risk factors. The number of risk factors for high risk soft tissue sarcoma seem to influence DMFS. Neoadjuvant treatment increases the risk only for wound infection treated with oral or intravenous antibiotic therapy and appears to be a safe option at an experienced tertiary center in absence of other risk factors.

Keywords: Multimodal therapy; Postoperative complications; Radiotherapy; Soft tissue sarcoma.

Fig. 1

Kaplan–Meier curves demonstrating oncologic outcomes stratified by the tumor localization for the whole cohort. Worse OS-rates with trend to statistical significance were observed in patients with STS localized in lower extremity. No difference in LC, DMFS and DFS was observed between patient cohorts

Fig. 2

Panel a. Kaplan–Meier curves demonstrating oncologic outcomes stratified by number of tumor high-risk features for the whole cohort (patients with missing data excluded). Compared to patients with ≤ 2 high-risk features, worse DMFS-rates were observed in patients with all 3 high-risk STS features, no difference in OS, LC and DFS was shown. Panel b. Patients with all three high risk features were more often treated with neoadjuvant therapy, as well as with complete multimodal therapy (perioperative radiation therapy with both, concomitant chemotherapy and hyperthermia)

Fig. 3

Bar graphs showing the influence of preexisting diabetes (diabetes mellitus type 1 or type 2) on major wound complications in patients with STS in lower extremity. Patients without diabetes had lower rate of wound infections and abscesses. A trend to statistical significance was observed for wound healing complication and fistula. No significant correlation between diabetes and seroma or hematoma was found

Fig. 4

Pie charts demonstrating the distribution of minor and major wound complications for lower extremities, as well as the proportion of patients where no treatment regarding wound complications was needed (either no complication or patients with clinical or imaging finding where no treatment was needed). Most of the patients had either no complications or only imaging finding where no treatment was needed. Wound healing disorder was observed in 15 patients (38.5%). Conservative treatment was applied in 5/39 patients (12.8%), surgical treatment was needed in 10/39 patients (25.6%). In total, 7/39 patients had postoperative seroma (17.9%). A drainage or seroma aspiration was needed in 3/39 (7.7%) patients. Surgical intervention was needed in 4/39 (10.3%) patients (classified as major wound complication). Postoperative hematoma was documented in 2/39 patients (5.1%). Surgical treatment was performed in all patients with hematoma requiring intervention