Prognostic significance of lymph node metastasis of soft tissue sarcoma of the extremities. National cancer institute experience

Background and objective Lymph node metastasis (LNM) in soft tissue sarcoma (STS) of the extremities is relatively rare. We aimed to evaluate the prognosis and the survival of patients with LNM and correlate them to the pattern of metastasis. Methods A retrospective study of patients diagnosed with STS of the extremities from 2015 to 2019. Results 111/1506 patients (7.4%) had LNM. Nodal metastasis was correlated significantly with old age, advanced tumor stages, high-grade tumors, presence of Lymphovascular invasion (LVI), and resection margins < = 2 cm. Metachronous LNM was documented in 96 patients (86.5%) and synchronous LNM in 15 patients (13.5%). The 6-year overall survival (OS) was 36.3% for those with LNM and 52.9% for those without LNM. The 6-year disease-free survival (DFS) was 5.7% for those with LNM and 32.6% for those without LNM. Metachronus pattern of LNM showed a significantly poorer outcome regarding 6-year OS and DFS than the synchronous pattern. Conclusions LNM significantly negatively predicts OS and DFS in the extremities' STS. In particular, the metachronous pattern of LNM indicates a grave prognosis as these patients are supposed to harbor an occult LNM at presentation and were not subjected to lymphadenectomy at their initial primary treatment surgery. Therefore, seeking a valid noninvasive diagnostic tool such as sentinel lymph node biopsy to detect nodal metastasis is necessary.