The Royal Marsden Solitary fibrous tumours The outcomes of 106 patients illustrating the unpredictable biological behaviour N Alexander, K Thway, JM Thomas, A Hayes, DC Strauss Mr Dirk Strauss Consultant Surgeon

The Royal Marsden Introduction –Solitary fibrous tumours (SFT) are rare spindle cell tumour –May arise anywhere in body –Characteristic hypervascular tumours

The Royal Marsden Introduction –Solitary fibrous tumours (SFT) are rare spindle cell tumours –May arise anywhere in body –Characteristic hypervascular tumours VEGF over-expressed

The Royal Marsden Introduction –Solitary fibrous tumours (SFT) are rare spindle cell tumour –May arise anywhere in body –Characteristic hypervascular tumours VEGF over-expressed –Unpredictable behaviour “Benign SFT: Although no malignant features are seen, the behaviour of these tumours is unpredictable.”

The Royal Marsden Benign vs. Malignant SFT Benign or malignant –Hypercellular –Nuclear polymorphism –Mitotic count > 4/10hpf –Presence of necrosis

The Royal Marsden SFT are unpredictable Case A –42 male –Vascular pelvic mass

The Royal Marsden SFT are unpredictable Case A –42 male –Vascular pelvic mass Case B –40 female –Vascular pelvic mass

The Royal Marsden SFT are unpredictable Case A –EUA and core needle biopsy –Solitary Fibrous Tumour (Benign) –Surgical resection incomplete resection due to significant pelvic bleeding

The Royal Marsden SFT are unpredictable Case A –EUA and core needle biopsy –Solitary Fibrous Tumour (Benign) –Surgical resection incomplete resection due to significant pelvic bleeding Case B – EUA and core needle biopsy x 2 – Solitary Fibrous Tumour (Benign) – Minimal clinical symptoms therefore opted to watch and wait

The Royal Marsden SFT are unpredictable Case A –6 years following incomplete resection –continuing radiological observation of residual tumour -> stable and unchanged

The Royal Marsden SFT are unpredictable Case A –6 years following incomplete resection –continuing radiological observation of residual tumour -> stable and unchanged Case B – 13 months from diagnosis presented with right arm pain and lytic lesion in humerus + lung metastases – died within 3 years of diagnosis

The Royal Marsden Aim –To review the clinical outcomes of patients managed with extra-pleural SFT

The Royal Marsden Method –Retrospective review –Cases identified from histopathology database and prospective unit database –Classified as benign or malignant on basis of histopathology (surgery, biopsy) –Data collection included site, size, overall survival, local and systemic disease recurrence

The Royal Marsden Results - Demographics 106 cases identified 51 males, 55 female median age = 60 years (range ) 58 benign vs. 48 malignant

The Royal Marsden DemographicBenign (n=58)Malignant (n=48) Sex Male 30 Female 28 Male 21 Female 27 Median Age59yrs60yrs Tumour location Limb/limb girdle Abdominal Tumour Size <5cm 5-10cm 10-15cm 15-20cm >20cm Results - Demographics

The Royal Marsden Results - Site and Size

The Royal Marsden Results - Treatment –91 patients underwent surgical resection Followed up for median 45 months (range 3-144) 2 patients died in perioperative period –15 elected not to operate 9 radiologic surveillance 4 primary radiotherapy 2 primary chemotherapy

The Royal Marsden Results - watch N = 9 patients: 8 abdomen/pelvis, 1 limb girdle –Benign SFT on biopsy –Serial cross sectional imaging Median follow up 28 months (11-60) –1 death at 37 months metastasis –5 stable disease 11 – 55 months –3 marginal increase over 28, 37, 60 months

The Royal Marsden Results - Histopathology –58 benign vs. 48 malignant –91 patient had a biopsy + surgical resection –Final pathology diagnosis of resection specimen was different to core needle biopsy in 18 patients (20%)

The Royal Marsden

Results - surgery BenignMalignant Local recurrence9% (4/46)31% (14/45) Time to Local recurrence 54 months (12-95) 16 months (3-84)

The Royal Marsden Results - surgery BenignMalignant Local recurrence9% (4/46)31% (14/45) Time to Local recurrence 54 months (12-95) 16 months (3-84) Distant Metastasis4% (2/56) 40% (25/48) Time to Distant Metastasis 13 months 101 m0nths 30 months (0-142)

The Royal Marsden BenignMalignant 5yr local recurrence free93%65% Results - surgery

The Royal Marsden BenignMalignant 5yr metastasis free survival98%62% Results

The Royal Marsden Results BenignMalignant 5yr overall survival96%46% 10yr overall survival96%26%

The Royal Marsden Primary radiotherapy N = 4 patients –1 malignant SFT, 3 benign SFT Size –2 stable (14, 49 months) –2 regression (32, 43 months)

The Royal Marsden Primary radiotherapy March 2011 –> August 2013

The Royal Marsden Response Assessment in Radiotherapy T2W ADC Contrast enhanced BOLD 2 weeks following radiotherapy

The Royal Marsden Conclusion –Oncological behaviour of SFT is unpredictable

The Royal Marsden Conclusion –Oncological behaviour of SFT is unpredictable –Available pathologic markers of malignancy clearly correspond to a malignant behaviour with poor prognosis

The Royal Marsden Conclusion –Oncological behaviour of SFT is unpredictable –Available pathologic markers of malignancy clearly correspond to a malignant behaviour with poor prognosis –However: many pathological markers subjective: cellularity, necrosis, pleomorphism –Risk model similar to GIST (mitotic index/size/site/age/margins/??) –Benign v malignant: simplistic/confusing low/intermediate/high risk SFT

The Royal Marsden Conclusion –Oncological behaviour of SFT is unpredictable –Available pathologic markers of malignancy clearly correspond to a malignant behaviour with poor prognosis –Core needle biopsy may not represent final diagnosis

The Royal Marsden Conclusion –Oncological behaviour of SFT is unpredictable –Available pathologic markers of malignancy clearly correspond to a malignant behaviour with poor prognosis –Core needle biopsy may not represent final diagnosis –Late relapses can occur in SFT

The Royal Marsden Conclusion –A cohort of difficult location tumours may be managed with observation

The Royal Marsden Conclusion –A cohort of difficult location tumours may be managed with observation –Radiotherapy: vascular effect +/- multikinase anti-angiogenesis inhibitors primary treatment/neoadjuvant treatment in tumours in difficult locations

The Royal Marsden Thank you