CLINICAL CHARACTERISTICS AND TREATMENT OUTCOMES IN PATIENTS WITH ADVANCED FIBROLAMELLAR HEPATOCELLULAR CARCINOMA – A TERTIARY CENTER EXPERIENCE

Introduction: Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare primary liver malignancy that is more often diagnosed in younger patients in the absence of underlying liver diseases. Given the high incidence of metastatic spread at diagnosis and recurrences after resection, systemic agents have been implemented. However, data on the efficacy of specific agents and regimens are scarce, except for small series and reports. Objective We aim to report clinical characteristics and outcomes in a cohort of patients with FLHCC treated with systemic treatment. Method We retrospectively reviewed medical records from patients with FLHCC treated at Instituto do Câncer do Estado de São Paulo from 2010-2022. Descriptive statistics were used for baseline demographics, and time-to-event outcomes were estimated by Kaplan Meier method. Result We identified 27 patients: 15 (55.5%) were female and median age was 23.6 years old (IQR: 20.6-29.1). Most of them had no comorbidities (77. 8%) neither family history of cancer (85.2%). Eighteen patients (66.7%) had metastasis at diagnosis (29.6% lymph node, 29.6% lung, 18.5% peritoneum and 3.7% bone). Nineteen patients (70.4%) underwent surgical resection; 3 (11.1%) received radiofrequency ablation and 1 (3.7%) stereotactic radiation. Twenty-two patients (81.5%) received systemic therapy, with a median of 3 lines (range: 1-8). The most frequently used regimens in 1st-line were sorafenib (40.9%), capecitabine (36.4%) and capecitabine + interferon (13.6%). The disease control rate (DCR) for the 1st-line was 40.9% and the median time to 1st line failure was 3.7 months (95%CI: 2.9-7.7). The most used 2nd-line regimens were capecitabine + interferon (50%) and platinum combinations (11.1% Gemcis, 16.7% Gemox 5.6% Cape+cis, 5.6% Flox), with a DCR of 44.4% and a time to 2nd line failure of 6.8 months (95%CI: 2.8-11.6). The median overall survival (OS) for patients treated with systemic treatments was 26.7 months (95%CI: 15.1-40.4), with a trend toward better survival for patients without peritoneal metastatsis (29.6 mo vs 19.7 mo; p= ns). Conclusion: Our cohort confirms that FLHCC presents unique features comparing to conventional HCC, regarding young onset, gender balance and absence of hepatopathy. The OS was comparable to other series. Although chemotherapy may provide encouraging DCR, the lack of uniformity precludes the definition of a preferable regimen, what reflect the lack of solid evidences on FLHCC management.