Characteristics and outcomes of soft tissue sarcoma in Saudi Arabia.

Abstract

e23544 Background: Soft tissue sarcomas (STS) are a rare heterogeneous group of neoplasms that count for less than one percent of all solid cancers in adults. There is limited data from Saudi Arabia (SA). We aimed to describe the disease characteristics and clinical outcome of STS from a specialized referral center in STS management in SA. Methods: All adult patients treated at King Faisal Specialist Hospital and Research Center between January 2010 and December 2019 were reviewed. Continuous variables are described in median and interquartile range, and categorical variables are described in frequency and compared by the Chi-square test. Survival analysis was estimated by the Kaplan-Meier method and compared by the Log-Rank test. Results: Two hundred fourteen patients diagnosed with soft tissue sarcoma were eligible for the study. The median age at diagnosis was 38 years old (IQR: 26-50.5), and males were (56.1%). The most common histology subtypes were synovial sarcoma (19.6%), liposarcoma (13.5%), undifferentiated pleomorphic sarcoma (11.6%), leiomyosarcoma (9.8%). The most common presentation was painless swelling (49.1%), and the median duration of symptoms was 8 (IQR: 4–13) months. The majority (131 patients, 61.2%) were localized diseases, and the most common primary site was the lower limb (62.1%). The median tumor size was 10 (IQR: 6.8-15) cm, and the tumors were deep to fascia in 144 (67.3%) patients. Eighty-three patients (38.8%) presented with de novo metastasis, and lung (81.9%) was the most common site. The local therapy was as follows; surgery (45.3%), radiation (7.5%), both (41.6%), and none (5.6%). Eighty-five patients received chemotherapy as follows; anthracycline (51%), ifosfamide (28%), and both (23.5%). Seventy-nine patients (36.9%) achieved complete response, 56 (26.2%) developed distant metastasis, and 11 (5.1%) local relapse. Thirty-one patients received salvage chemotherapy, and 30 patients received second-line chemotherapy. The best response of first-line chemotherapy in metastatic patients was CR (3%), PR (14%), SD (8%), and PD (63%). The median follow-up was 37 (IQR: 12-76.75) months. The median OS for the localized disease was not reached, and three years OS was 88.2%. There was a statistical difference in OS between extremities vs. trunk (90.9% vs. 66.7%), (p = 0.01), histological subtypes (p = 0.006), nodal involvement (p < 0.001), T stage (p = 0.03), and complete response 96.9 vs. 68.5% (p < 0.001). The median OS for metastatic disease was 26 (95% CI: 16–35.5) months. The median OS for patients who underwent surgery, radiation, both or none were 26, 23, 31, and 9 months, respectively (p = 0.004). Conclusions: STS in SA is diagnosed at a younger age, with a longer median time for diagnosis and a more advanced stage. Histological subtypes and the advantage of local disease control and metastasectomy are consistent with other figures.