Photodynamic therapy: A next alternative treatment strategy for hepatocellular carcinoma?

Abstract

Liver cancer is one of the most common cancers in the world. Of all types of liver cancer, hepatocellular carcinoma (HCC) is known to be the most frequent primary liver malignancy and has seriously compromised the health status of the general population. Locoregional thermal ablation techniques such as radiofrequency and microwave ablation, have attracted attention in clinical practice as an alternative strategy for HCC treatment. However, their aggressive thermal effect may cause undesirable complications such as hepatic decompensation, hemorrhage, bile duct injury, extrahepatic organ injuries, and skin burn. In recent years, photodynamic therapy (PDT), a gentle locoregional treatment, has attracted attention in ablation therapy for patients with superficial or luminal tumors as an alternative treatment strategy. However, some inherent defects and extrinsic factors of PDT have limited its use in clinical practice for deep-seated HCC. In this contribution, the aim is to summarize the current status and challenges of PDT in HCC treatment and provide potential strategies to overcome these deficiencies in further clinical translational practice.

Keywords: Hepatocellular carcinoma; Photodynamic therapy; Photosensitizers; Aggregation-induced emission; Targeted therapy; Nanoparticles

Core tip: The application of photodynamic therapy (PDT) in hepatocellular carcinoma (HCC) therapy is limited due to its low penetration depth of light irradiation, the reduced generation of reactive oxygen species by conventional photosensitizers in the aggregated state, and the nontargeted accumulation in cancer cells. Once these problems are resolved, PDT will be a promising alternative treatment strategy for HCC.