Size selection of intrahepatic lesions for cryoablation contributes to abscopal effect and long-term survival in patients with liver metastatic melanoma receiving PD-1 blockade therapy.

OBJECTIVES: In this study, we aimed to examine parameters of cryoablation, tumor characteristics, and their correlations with distant tumor response and survival of liver metastatic melanoma patients receiving cryoablation and PD-1 blockade (cryo-PD-1) combination treatment. MATERIALS AND METHODS: A retrospective study was conducted among 45 melanoma patients who received combined PD-1 blockade therapy and cryoablation for liver metastasis from 2018 to 2022. Cox regression was utilized to determine the associations between factors and overall survival (OS). Changes in cytokines and immune cell compositions in peripheral blood samples following the combined treatment were investigated, along with their correlations with treatment response. RESULTS: The mean cycle of cryo-PD-1 combination treatment was 2.2 (range, 1-6), and the 3-month overall response rate (RECIST 1.1 criteria) was 26.7%. Of the 21 patients who failed previous PD-1 blockade therapy after diagnosis of liver metastasis, 4 (19.0%) achieved response within 3 months since combination treatment. The diameter of ablated lesion ≤ 30 mm, metastatic organs ≤ 2, and pre-treatment LDH level ≤ 300 U/L were independent prognostic factors for favorable OS. Further analysis showed patients with intrahepatic tumor size of 15-45 mm, and ablated lesion size of ≤ 30 mm had significantly higher 3-month response rate (42.9% vs 12.5%; P = 0.022) and survival time (30.5 vs 14.2 months; P = 0.045) than their counterparts. The average increase in NLR among patients with ablated tumor size of ≤ 3 cm and > 3 cm were 3.59 ± 5.01 and 7.21 ± 12.57, respectively. The average increase in serum IL-6 levels among patients with ablated tumor size of ≤ 3 cm and > 3 cm were 8.62 ± 7.95 pg/ml and 15.40 ± 11.43 pg/ml, respectively. CONCLUSION: Size selection of intrahepatic lesions for cryoablation is important in order to achieve abscopal effect and long-term survival among patients with liver metastatic melanoma receiving PD-1 blockade therapy.

A Prospective, Single-Arm, Phase 2 Study of Modified Transarterial Chemoembolization Using Low-Dose Chemotherapy with Blank Microspheres Plus Low-Dose Lenvatinib and Microwave Ablation in Patients with Large (≥7 cm) Unresectable Hepatocellular Carcinoma: The TALEM Trial.

Introduction: For patients with large unresectable hepatocellular carcinoma (HCC), the effectiveness of conventional transarterial chemoembolization (cTACE) remains suboptimal. This study investigated the efficacy and safety of modified TACE using low-dose chemotherapy with blank microspheres (BMS-TACE) plus low-dose lenvatinib (LD-LEN) and microwave ablation (MWA) in patients with large unresectable HCC. Methods: In this prospective, single-arm, phase 2 study, patients with unresectable HCC exceeding the up-to-seven criteria, with maximum tumor diameter ≥7 cm, and without macrovascular invasion or extrahepatic metastases, received initial BMS-TACE (lipiodol, low-dose doxorubicin, and lobaplatin up to 30 mg each, and blank microspheres; subsequently modified and repeated in most patients) plus LD-LEN (4-8 mg/day) and MWA. The primary endpoint was downstaging rate (DSR); secondary endpoints were objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and adverse events. Results: From November 2019 to March 2022, 43 patients were enrolled. Median follow-up was 21.2 months. Median largest tumor diameter was 11.2 cm (interquartile range [IQR], 7-25). Following BMS-TACE and LD-LEN, downstaging occurred in 37 (86.0%) patients, 32 of whom received MWA, and 8 of whom had a complete response (CR) without MWA. ORR was 93.0% (CR in 32 [74.4%] and partial response in 8 [18.6%] patients). The 1-, 2-, and 3-year PFS rates were 57.5%, 25.9%, and 18.1%, respectively (median PFS, 14.7 months [95% CI: 8.1-19.5]). The 1-, 2-, and 3-year OS rates were 85.8%, 67.7%, and 61.6%, respectively (median OS, 36.4 months [95% CI: 26.8-not reached]). After BMS-TACE, a significant decline in CD11b+/CD33+/HLA-DR- myeloid-derived suppressor cells and early elevation in CXCR5+/CD8+ and CXCR5+/CD4+ T cells were observed (both p < 0.05). Conclusion: BMS-TACE plus LD-LEN and MWA resulted in promising efficacy and tolerable toxicity in patients with large unresectable HCC exceeding the up-to-seven criteria with a maximum tumor diameter ≥7 cm and without macrovascular invasion or extrahepatic metastases.