Every year, approximately 19 million new cases of cancer are diagnosed worldwide [1]. Soft tissue sarcomas (STS) represent only 1 % of all adult malignant neoplasms, with an estimated prevalence of 180,000 to 200,000 cases globally. Europe reports a higher incidence of 4–9 cases per 100,000 per year [2], followed by North America with 1.8–5 cases per 100,000 per year [3]. However, data on the incidence of STS in Latin America (LATAM) remain scarce.

STS are a group of rare, malignant tumors of mesenchymal origin. Despite their rarity, they encompass more than 70 distinct subtypes classified by the World Health Organization (WHO) [4], with the last updated version integrating newly identified genetic alterations and prognostic markers [5,6].

Multidisciplinary management is essential to achieving optimal outcomes in sarcomas. However, the cornerstone treatment for extremity soft tissue sarcomas (ESTS) remains function-sparing surgical excision with wide margins. This surgical approach may be complemented with chemotherapy and radiotherapy, depending on high-risk features such as histology, tumor grade, tumor size, deep localization, and nomogram-based estimates of recurrence and overall survival [7,8].

Due to the rarity of these neoplasms, a significant proportion of cases experience delayed diagnosis. This delay often results from inexperienced management by health professionals who overlook the need for preoperative biopsy and histological diagnosis. Furthermore, the management of primary STS is frequently performed by non-specialized oncologists, leading to deviations from standard protocols to achieve adequate macroscopic and microscopic resection margins [9,10]. Giuliano and Eilber introduced the term “unplanned total excision,” highlighting a concerning trend where tumors initially presumed benign are excised without proper preoperative preparation. This can lead to incomplete or inadequate treatments [11,12]. Controversy remains regarding whether these unplanned resections negatively impact oncological outcomes—including local recurrence, distant recurrence, and overall survival—in patients with ESTS [13,14].

This study's objective was to retrospectively analyze the presence of residual disease following initial excision at external institutions among patients who underwent unplanned resections for extremity soft tissue sarcomas. Additionally, we aimed to compare the oncologic outcomes of this population to those of patients who underwent initial planned resections at a high-volume referral sarcoma center in Latin America.