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The natural history and prognosticative factors of adult extremity soft tissue sarcomas: an Asian perspective.

INTRODUCTION
We describe the natural history of Asian adult soft tissue sarcomas (STSs) in the extremities and predict prognosticative factors for local recurrence, metastasis and tumour-related death.


MATERIALS AND METHODS
Between January 1999 and May 2009, 67 adult patients with first presentation STSs of extremity sites underwent surgical treatment at a single institution. The associations between patient demographics and pathological features with local recurrence, metastasis and mortality were studied using univariate and multivariate analysis.


RESULTS
The mean age of our patients was 52.4 years with most presentations occurring in the thigh. Majority of Asian STSs were high grade (61.3%) and large tumours with 81.0% being >5 cm. Stages Ia, Ib, IIa, IIb, IIc, III and IV accounted for 6.6%, 6.6%, 26.2%, 11.5%, 3.3%, 42.6% and 3.3% of presentations, respectively. Patients were followed-up for a mean period of 45.9 months. On univariate analysis, high tumour grade and advanced stage (IIc to IV) were predictive of local recurrence and metastasis. Deep lesions were more likely to recur but not metastasise or cause death. Age, sex, size, and margin positivity were not predictive for all end-points. On multivariate testing, only pathological high grade was associated adversely with local recurrence [odds ratio (OR) = 10.0, 95% CI, 1.2 to 84.9, P = 0.035], metastasis (OR = 12.7, 95% CI, 2.46 to 65.2, P = 0.002) and mortality (OR = 16.2, 95% CI, 1.95 to 135.0, P = 0.010).


CONCLUSIONS
Asian adult extremity soft tissue sarcomas present late and are most commonly found in the thigh. High pathological grade is a consistent independent predictor for local failure, distant spread and tumour-related death. Our results reaffirm the current thinking that tumour biology is of primary importance in determining patient outcomes.