The Royal Marsden

Solitary fibrous tumours

The outcomes of 106 patients illustrating the unpredictable biological behaviourN Alexander, K Thway, JM Thomas, A Hayes, DC

Strauss

Mr Dirk StraussConsultant 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 MarsdenBenign vs. Malignant SFTBenign or malignant

– Hypercellular

– Nuclear polymorphism

– Mitotic count > 4/10hpf

– Presence of necrosis

The Royal MarsdenSFT are unpredictable

Case A– 42 male– Vascular pelvic mass

The Royal MarsdenSFT are unpredictable

Case A– 42 male– Vascular pelvic mass

Case B– 40 female– Vascular pelvic mass

The Royal MarsdenSFT are unpredictable

Case A

– EUA and core needle biopsy

– Solitary Fibrous Tumour (Benign)

– Surgical resection• incomplete

resection due to significant pelvic bleeding

The Royal MarsdenSFT 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 MarsdenSFT are unpredictable

Case A

– 6 years following incomplete resection

– continuing radiological observation of residual tumour -> stable and unchanged

The Royal MarsdenSFT 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

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Aim

– To review the clinical outcomes of patients managed with extra-pleural SFT

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Method– Retrospective review 2000-2012

– 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

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Results - Demographics

• 106 cases identified

• 51 males, 55 female

• median age = 60 years (range 18 - 88)

• 58 benign vs. 48 malignant

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Demographic Benign (n=58) Malignant (n=48)

Sex Male 30Female 28

Male 21Female 27

Median Age 59yrs 60yrsTumour location• Limb/limb girdle• Abdominal

3325

2523

Tumour Size• <5cm• 5-10cm• 10-15cm• 15-20cm• >20cm

6221558

2141485

Results - Demographics

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Results - Site and Size

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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

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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

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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%)

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Results - surgery

Benign Malignant

Local recurrence 9% (4/46) 31% (14/45)

Time to Local recurrence

54 months (12-95)

16 months (3-84)

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Results - surgery

Benign Malignant

Local recurrence 9% (4/46) 31% (14/45)

Time to Local recurrence

54 months (12-95)

16 months (3-84)

Distant Metastasis 4% (2/56) 40% (25/48)

Time to Distant Metastasis

13 months101 m0nths

30 months(0-142)

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Benign Malignant5yr local recurrence free

93% 65%

Results - surgery

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Benign Malignant5yr metastasis free survival

98% 62%

Results

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Results

Benign Malignant5yr overall survival 96% 46%

10yr overall survival 96% 26%

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Primary radiotherapy

N = 4 patients– 1 malignant SFT, 3 benign SFT

Size– 2 stable (14, 49 months)– 2 regression (32, 43 months)

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Primary radiotherapy

March 2011 –> August 2013

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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

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Thank you