Study design and patient selection
This study was approved by our institutional review board, and written informed consent was obtained from every patient. Data of consecutive patients with advanced HCC who received TACE-L-P or TACE-L at our institution between January 2019 and December 2020 were prospectively collected and retrospectively analyzed.
The inclusion criteria for this study were as follows: (1) age between 18 and 75 years; (2) confirmed diagnosis with HCC [2, 24] accompanied by macrovascular invasion and/or extrahepatic metastasis; (3) tumor recurrence after curative resection or ablation was allowed; (4) Eastern Cooperative Oncology Group performance status (ECOG PS) of ≤1; and (5) Child-Pugh class A/B. Patients were excluded if they (1) had central nervous system metastasis; (2) had history of organ transplantation; (3) previously received TACE, hepatic arterial infusion chemotherapy (HAIC), radiotherapy or systemic therapy; (4) had other malignancies in addition to HCC; or (5) had severe medical comorbidities including severe cardiac, pulmonary, renal or coagulation dysfunction.
All laboratory test data were collected within 3 days before the initial treatment. Contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) was performed within 7 days before the initial treatment.
TACE procedure
The patients received either conventional TACE (cTACE) or drug-eluting bead TACE (DEB-TACE) according to their own choice. For cTACE, an emulsion of 5-20 mL Lipiodol (Guerbet, Paris, France) mixed with 20-60 mg pirarubicin (Hisun Pfizer Pharmaceuticals, Fuyang, China) was administered into the tumor-feeding vessels, followed by embolization with polyvinyl alcohol particles (90-500 μm; Cook, Bloomington, Indiana, USA). For DEB-TACE, CalliSpheres(Hengrui Medical, Suzhou, China) or DC Bead (Biocompatibles, Farnham, Surrey, UK) with 100-300 μm in diameter was used as the drug carrier and embolization agent. Typically, one vial of the beads was loaded with 60 mg pirarubicin. If blushed tumors were still visible after the embolization with one vial of beads, regular microspheres (8spheres, Hengrui Medical, Suzhou, China; Embosphere, Biosphere Medical, Roissy en France, France) with diameters of 100-700 μm were additionally injected [25].
During TACE, superselective catheterization was performed, and the embolization end point was blood stasis of the tumor-feeding arteries. In patients with huge or bilobar multiple lesions, in order to reduce the risk of complications, the embolization end point was not achieved in the initial TACE but in the second or third TACE session [26]. In the case of arterioportal or arteriovenous fistula, the fistula would be embolized with 300-710 μm polyvinyl alcohol particles before administration of the drug-oil emulsion or drug-loaded beads.
TACE was repeated “on demand” upon the demonstration of viable tumor by follow-up CT or MRI in patients without deteriorated performance status or organ function.
Lenvatinib and PD-1 inhibitor administration
Lenvatinib (Eisai, Tokyo, Japan) and PD-1 inhibitor was initiated within 7 days after the first TACE. Lenvatinib at a dose of 12 mg (bodyweight ≥60 kg) or 8 mg (bodyweight <60 kg) was orally administered once a day. The PD-1 inhibitor sintilimab (Innovent Biologics, Suzhou, China), tislelizumab (BeiGene, Shanghai, China) or camrelizumab (Hengrui Pharma, Lianyungang, China) was injected intravenously at 200 mg once every 3 weeks. The interruption and discontinuation of drug administration depended on the presence and severity of toxicities according to the drug directions.
Follow-up
Regular follow-up was conducted for all patients at a 3-6-week interval after the initial treatment. Each follow-up session included a detail history, physical examination, hematologic and biochemical tests, contrast-enhanced abdominal CT or MRI, chest CT, and other imaging examination if clinically indicated. The finial follow-up ended on June 30, 2021.
During follow-up, the treatment of TACE-L-P or TACE-L was discontinued in cases of intolerable toxicity, progressive disease (PD) or change of treatment plan. And, the choice of the subsequent treatment, such as second-line targeted agent, PD-1 inhibitor (for the patients treated with TACE-L), radiotherapy (including iodine-125 seed brachytherapy), HAIC or best supportive care, was determined according to the results of discussion by our multidisciplinary team and the patients’ request.
Assessments and outcomes
OS and progression-free survival (PFS) were compared between TACE-L-P group and TACE-L group. OS was defined as the time from treatment initiation until death by any reason. PFS was defined as the time interval from treatment initiation to the first occurrence of PD or death, whichever occurred first.
Tumor responses were categorized as complete response (CR), partial response (PR), stable disease (SD) or PD according to mRECIST. Overall tumor response referred to the assessment of changes in tumor burden inside and outside the liver, while intrahepatic tumor response only included the assessment of changes in tumor burden inside the liver. ORR was defined as the percentage of patients who had a best tumor response rating of CR and PR. Disease control rate (DCR) was defined as the percentage of patients who had a best tumor response rating of CR, PR and SD.
Adverse events (AEs) related to treatments were recorded and assessed based on Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Postembolization syndrome (manifested by fever, abdominal pain, nausea, vomiting and increased white blood cell count) and transient abnormalities of liver enzyme after TACE [27, 28] were expected and would resolved within a short time, and therefore, they were not documented separately.
Statistical Analyses
Categorical data were expressed as number of patients (percentage). Quantitative data were expressed as mean±standard deviation and median (range) for normally and non-normally distributed variables, respectively. Categorical data between the two groups were compared using χ2 test or Fisher’s exact test, as appropriate. Quantitative data were compared using Student’s t-test or Mann-Whitney U test, as appropriate. Survival curves were analyzed by Kaplan-Meier method using log-rank test. Variables with p<0.10 in univariate analysis were entered into a multivariate analysis using Cox regression model to identify the independent prognostic factors for OS and PFS. All statistical analyses were performed with SPSS Statistics version 22 (IBM, Armonk, New York, USA). All statistical tests were two-tailed, p<0.05 was considered statistically significant.