Editing Soft tissue sarcoma (section)

=== '''Extremity or trunk wall STS''' ===

** Proximal limb more commonly affected than distal, with 44% of examples found in thigh
** Imaging alone is rarely diagnostic, with the exception of well-differentiated liposarcoma - these can be directly excised based on imaging
** Others will need biopsy
*** Incisional biopsy: longitudinally-oriented incision in such a way that the incision can be excised when a definitive resection is done.
*** Excisional biopsies are appropriate with lesions <2cm in size and superficial location
** Excision:
*** Two options
**** Amputation
**** Limb salvage (now standard of care)
***** Consider size, grade, type, any adjacent involvement, fitness, future functional capacity of limb going to be better than amputation
***** The margin size is inversely proportional to risk of recurrence
***** Treat margin with radiotherapy in almost all cases
*** The pseudocapsule will be seen as a characteristic plane of thickened tissue that gives the impression of being the interface between tumour and normal tissue. This will seem to be the plane of least resistance during excision. However, that will generally lead to positive margins. Need to go 1-2cm beyond it.
*** Include entire tumour without rupture of pseudocapsule and 1-2cm margin (quantitative definition of what constitutes an adequate margin has never been established)
*** Patients with positive margins should be offered re-resection to a new margin of 1cm
*** Place clips at the boundaries of the resection bed in case adjuvant radiotherapy is needed
*** If margin is positive, radiotherapy will be required
*** Planned positive margins at critical structures can be treated with pre-op RTX, with no change to overall survival
*** Excise skin if it is within margin
*** Superficial tumours involving fascia should include a margin of fascia and maybe underlying muscle
*** Include periosteum as margin
*** Consider involving vascular or plastic surgeons for reconstruction of vessels/nerves
*** Use orientation sutures on specimen
*** Drains may be necessary, especially after neoadjuvant RTX, or in setting of recurrent tumours. If placing a drain, have the skin exit site within a planned radiotherapy field - the whole drain tract will be treated.
** Radiotherapy
*** Limb-sparing surgery requires radiation to treat margin
*** Studies have shown no difference between pre-op and post-op RTX
** Chemotherapy
*** Conflicting data regarding efficacy
*** Consider in those with concerning features - >10cm tumour, deep, high-grade histology, certain higher-risk subtypes
*** Usually doxorubicin/ifosfamide
*** Hyperthermic isolated limb perfusion/infusion has been investigated for locally advanced disease in whom limb-sparing, function-sparing surgery may not be possible
*** Immunotherapies considered as part of a trial