Bone invasion in soft tissue sarcomas of the extremities: An underappreciated prognostic factor. Bone invasion in soft tissue sarcomas.

BACKGROUND: Bone invasion is unfrequently reported in soft tissue sarcomas of the extremities (eSTS), it is difficult to assess preoperatively and its prognostic impact has not been extensively studied. The objective of this paper was to analyze the incidence and the clinical impact of histologically proven bone invasion in individuals with eSTS. METHODS: A retrospective analysis was performed using the medical files patients who had eSTS and were treated between 2012 and 2016. A 5 years survival was estimated using the Kaplan-Meier method and a Cox proportional risk assessment. The outcomes of patients with and without bone invasion were compared. RESULTS: 370 patients were included in the analysis. The median follow up was 25 months, the median age was 45 years (IQR 31-58). Bone invasion was found in 41 (11.08%). Median tumor size was 11.8 cm. The majority of individuals were diagnosed at stage IV (n = 116, 31.4%), followed by stage IIIB (n = 87, 23.5%). High histological grade was associated with worse OS (HR 2.23, CI 95% 1.36-3.65, p = 0.001). Absence of bone invasion was associated with better prognosis (HR 0.541, CI 95% 0.34-0.86, p = 0.009). OS was 27.3 vs 49.28 months. The disease-free survival (DFS) was 25.1 in bone invasion vs 45.23 without bone invasion. CONCLUSION: Bone invasion in individuals with eSTS is an independent adverse prognostic factor associated with lower OS and DFS; although infrequently reported, bone invasion might be considered as part of the staging in the future.

Epidemiological profile of soft tissue sarcomas of the extremities: Incidence, histological subtypes, and primary sites.

BACKGROUND: Soft tissue sarcomas (STS) are a heterogeneous group of rare tumours that represent less than 1% of all malignant, solid tumours in adults. There is limited epidemiological information regarding STS in Latin America. Therefore, the objective of this study is to present an epidemiological profile of these tumours observed at a single reference centre. METHODS: A retrospective study was carried out based on hospital records obtained from a registry of 879 patients with STS of the extremities who were treated at the National Cancer Institute of Mexico from January 1, 1994 to December 31, 2017. Epidemiological variables and relevant clinical data were collected. Five-year survival rates were analysed using Kaplan-Meier estimates, and a multivariate Cox proportional-hazards model measured associations. RESULTS: A total of 879 records were collected. The median age was 45 years (15-95 years), and the ratio of men to women was 1:1, with 433 men (49.3%), and 446 women (50.7%). The median tumour size was 11.4 cm (2-49 cm). The most prevalent histological variants were liposarcomas and synovial sarcomas. The lower limb was the most frequently affected extremity, with the thigh being the most common site followed by the leg. A majority of the patients were diagnosed at clinical stages IIIA-IV. CONCLUSIONS: The data collected from the present cohort provides an overview of the epidemiological profile of STS at a single reference centre in Latin America, and allow comparison with global data.

Should metastatic lymph nodes be considered at the same clinical stage as distant metastasis in soft tissue sarcomas?

INTRODUCTION: Lymph node metastasis (LNM) in soft tissue sarcomas (STS) are uncommon, occurring in only 3% - 5% of all sarcomas, and are classified as Stage IV, along with distant metastasis (DM). This paper compares the prognosis of patients with lymphatic and DM, in extremity STS (eSTS). METHODS: A retrospective study was carried out in a high-volume sarcoma center; 853 patients with eSTS sarcomas were identified and classified from January 1, 1997 to December 31, 2017. Cases with pathological confirmation of LNM were included. Five-year survival rates were analyzed using the Kaplan-Meier method and the Cox proportional hazards model. RESULTS: LNM was present in 46 of the cases (5.4%), with an overall survival of 21 months (95% confidence interval [CI], 16.7 - 25.2), compared to 18 months (95% confidence interval [CI], 14.2 - 21.7) in those with only DM. Median recurrence-free survival was 21 months (95% confidence interval [CI], 19.7 - 22.4), vs. 20 months (95% confidence interval [CI], 16.2- 23.7), respectively. LNM only and DM only had also a similar OS of 21 months (95% CI 16.7-25.2) vs 18 months (95% CI 14.2-21.7. N1M1 cases had the worse median OS with 15 months (95% confidence interval [CI], 10.9-19.7) CONCLUSIONS: Overall survival and recurrence free survival in patients with lymph node disease and metastatic disease are similar. However prognosis is worse in N1M1. Use of systemic treatment in patients with LNM is not as common as in metastatic cases, this difference in treatment and the fact that prognosis is similar suggests that both biological behavior and effect of treatment have been underestimated. A subclassification of clinical stage IV might be the next step.