The role of surgical margin quality in myxofibrosarcoma and undifferentiated pleomorphic sarcoma

The effect of margin quality as a barrier against infiltration of soft-tissue sarcomas (STSs) has been unclear. We aimed to investigate the effect of margin quantity and quality on local control for myxofibrosarcoma (MFS) and undifferentiated pleomorphic sarcoma (UPS).

278 patients with a localised MFS and UPS were studied. Margin quality was categorized into five types; type 1, pseudocapsule/reactive zone; type 2, fat/fibrofatty tissue; type 3, muscle; type 4, fascia; type 5, periosteum.

The 5-year cumulative LR incidence was 22% and 13% in patients with positive and 0.1-9.9 mm margins, respectively, but decreased to 3% with ≥10.0 mm margins (p = 0.009); the cumulative LR incidence was significantly lower in patients with ≥10.0 mm margins than those with positive margins (p = 0.033) but was not significantly different in those with 0.1-9.9 mm margins (p = 0.183). In patients with 0.1-9.9 mm margins, the cumulative LR incidence was affected by margin quality; type 4 and 5 provided an LR risk less than 5% (p < 0.001), which was similar to those with margins ≥10.0 mm. Combining these two factors together, the LR risk in patients with positive or 0.1-9.9 mm margins without fascia/periosteum was approximately 11 × higher than patients with 0.1-9.9 mm margins with fascia/periosteum or margins ≥10.0 mm (p = 0.002).

A resection margin of 0.1-9.9 mm with fascia or periosteum provided a similar LR risk profile to ≥10 mm margins with any margin quality, which provided the lowest LR risk. The quality of fascial or periosteal tissue margins may be equivalent to a margin quantity of 10 mm as a barrier to LR.