A retrospective multicenter study on solitary fibrous tumors: investigation of clinical features and management approaches

Abstract

Aims: Solitary fibrous tumors are exceedingly rare neoplasms, for which surgical resection remains the cornerstone of treatment; however, long-term surveillance is imperative due to the significant risk of recurrence. We aimed to evaluate tumor characteristics and treatment responses in this multicenter study. Methods: Sixty-eight adult patients with histologically confirmed solitary fibrous tumor (SFT) diagnosed between 2010 and 2024 from seven cancer centers in Turkiye were included. Clinical and pathological features along with treatment outcomes were assessed. Results: The majority of patients (65/68 pts, 95%) presented with localized disease and underwent primary resection, while 3 patients had metastatic disease at the time of diagnosis. Further analyses were performed only in patients with localized disease. Median follow-up time was 41.7 months. All patients underwent primary surgery; R0 resection was achieved in most patients (66.2%). Five -year DFS and OS were 67% and 87%, respectively. DFS of extrameningeal SFTs was further evaluated according to clinicopathological variables. Low Ki-67 Labeling Index, low mitotic rate, and younger age were found to be associated with longer DFS. Response rates to first-line systemic therapy after recurrence was 27% with chemotherapy and while no objective responses were achieved with pazopanib. Two patients experienced disease control for up to 11 months with pazopanib. This study is limited by the relatively small sample size and the heterogeneity arising from the inclusion of both meningeal and extrameningeal tumors located at different anatomical sites. Conclusion: Localized SFTs usually have favorable prognosis. Patients with extrameningeal SFTs with younger age, low Ki-67 Index and low mitotic rate have longer survival. Once relapsed, repeat surgical resection should be pursued when possible. Response rates to systemic treatment is generally low.

Keywords

• Sarcoma
• surgery
• pazopanib
• solitary fibrous tumors
• scoring systems

Soliter fibröz tümörler üzerine retrospektif çok merkezli bir çalışma: klinik özellikler ve tedavi yaklaşımlarının incelenmesi

Abstract

Amaç: Soliter fibröz tümörler (SFT) son derece nadir görülen neoplazmlardır ve cerrahi rezeksiyon hâlâ tedavinin temel taşıdır; ancak nüks riski yüksek olduğundan uzun dönem takip zorunludur. Bu çok merkezli çalışmada tümör özelliklerini ve tedavi yanıtlarını değerlendirmeyi amaçladık. Yöntemler: 2010–2024 yılları arasında Türkiye’deki yedi kanser merkezinde histolojik olarak doğrulanmış SFT tanısı konulan 68 erişkin hasta çalışmaya dâhil edildi. Klinik ve patolojik özellikler ile tedavi sonuçları değerlendirildi. Bulgular: Hastaların büyük çoğunluğu (65/68 hasta, %95) lokalize hastalık ile başvurmuş ve primer rezeksiyon uygulanmışken, 3 hastada tanı anında metastatik hastalık mevcuttu. İleri analizler yalnızca lokalize hastalığı olan hastalarda yapıldı. Ortanca takip süresi 41,7 aydı. Tüm hastalara primer cerrahi uygulandı; hastaların çoğunda R0 rezeksiyon sağlandı (%66,2). Beş yıllık hastalıksız sağkalım (DFS) ve genel sağkalım (OS) oranları sırasıyla %67 ve %87 idi. Ekstrameningeal SFT’lerin DFS’i klinikopatolojik değişkenlere göre ayrıca değerlendirildi. Düşük Ki-67 indeksine, düşük mitotik hızına ve daha genç yaşa sahip hastalarda daha uzun DFS gözlendi. Nüks sonrası birinci basamak sistemik tedaviye yanıt oranı kemoterapi ile %27 iken, pazopanib ile objektif yanıt elde edilmedi. İki hastada pazopanib ile 11 aya kadar hastalık kontrolü sağlandı. Sonuç: Lokalize SFT’ler genellikle iyi prognoza sahiptir. Daha genç yaşta olan, düşük Ki-67 indeksine ve düşük mitotik hızına sahip ekstrameningeal SFT hastalarında sağkalım daha uzundur. Nüks durumunda, mümkünse tekrarlayan cerrahi rezeksiyon tercih edilmelidir. Sistemik tedaviye yanıt oranları ise genel olarak düşüktür.

Keywords

• sarcoma
• surgery
• pazopanib
• solitary fibrous tumors
• scoring systems

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