Metastatic Potential of Grade I XXXX : Results of a Multi-institutional Study.

@entity1 @entity511 @entity3478 @entity5 @entity79 @entity3
BACKGROUND: Little is known about the metastatic potential of low-grade @entity511 . This study was designed to evaluate the rate of @entity3 to identify possible risk factors. METHODS: The files of 225 @entity1 with newly diagnosed, grade I @entity79 treated between 1975 and 2012 were retrospectively analyzed. Median follow-up was 80  months for survivors (range 24-445  months). Nonparametric analyses were performed with the Mann-Whitney U test. Survival curves were calculated with the Kaplan-Meier method and compared with the log-rank test. RESULTS: Fourteen @entity1 developed @entity3 after a median of 49  months. @entity3 ( @entity3 ) was 95  % at 5  years and 92  % at 10  years. Post- @entity3 survival probability amounted to 27  % after 5  years. @entity5 size at diagnosis (P  =  0.698) and surgical margin width (P  =  0.514) had no influence on @entity3 . @entity1 who developed local recurrences had a significantly lower 10-year @entity3 than @entity1 without recurrences (69  % vs. 99  %, P  <  0.001). @entity1 with grade I recurrences had a significantly poorer @entity3 than @entity1 without recurrences (P  =  0.013) but a significantly higher @entity3 than @entity1 with grade II recurrences (P  =  0.006). @entity1 with @entity5 had a significantly lower 10-year @entity3 of 66  % compared with @entity1 with @entity5 of the upper (100  %, P  <  0.001) and lower extremity (93  %, P  =  0.033). CONCLUSIONS: The biological behavior of low-grade @entity511 appears to be more consistent with the WHO definition of rarely metastasizing @entity3478 , rather than the one of locally aggressive @entity5 . @entity5 and the development of local recurrences were associated with a higher @entity3 rate in this study.
