The purpose of TACE preoperation is to increase the chance of surgery in HCC patients, which is the so-called “conversion therapy”. In a narrow sense, conversion therapy refers to the downstaging of unresectable HCC [17, 18]. However, during the clinical application of this method, various reasons may exist in addition to tumor stage that may explain why patients cannot be treated with surgery temporarily. Therefore, it is believed that compared with “unresectable”, the concept of “temporarily unsuitable for surgery” is more suitable. The present study finally carried out surgical treatment for such patients successfully, which all can be termed “conversion therapy” cases. It is believed that this is a broad concept of conversion therapy, which can reflect the current clinical situation more accurately. In the present study, to the temporary lack of suitable surgery for patients may be attributed to several reasons, among which the individual choice of patients is worth mentioning. We often choose the best treatment for patients from the perspective of medical practice. However, after informing the patients of the advantages and disadvantages of various treatment methods, they have the right not to choose the best treatment measure in medicine. In this case, the treatment measure can be accepted by the patients to control the progression of the disease. The patients can wait patiently and communicate fully, so as to ensure the optimal selection of the best treatment measure. In the present study, 3 patients refused surgery at the beginning and selected TACE. Finally, the operation was performed successfully following full communication with the patients.
The ORR is a pivotal factor for downstaging . TACE has been considered as a means of downstaging [20,21] for some intermediate stage HCC patients in the last several years and performs better in ORR than both tyrosine kinase inhibitors (TKI) and the immune checkpoint inhibitor PD-1. The ORR of TACE for intermediate-stage HCC is estimated to 52.5%  and 63.3%. In the present study, the ORR of sorafenib (SHARP study) and lenvatinib (REFLECT study) was estimated to 2 and 24.1% respectively . Pembrolizumab demonstrated 18.4% ORR in the phase 3 KEYNOTE-240 trial, which was similar to that noted for lenvatinib . However, although higher ORR was noted, the success rate of downstaging was still low by TACE alone, notably in the intermediate stage HCC and was estimated to approximately 20% . In the present study, the downstaging rate in the NDS group was higher than that of the DS group (50% vs. 10%) although no statistical significance was noted. It is believed that the reason for the lack of statistical significance may be due to the small sample, which shows that the expected downstaging effect could not be achieved by TACE alone for the intermediate stage HCC. The combination of other therapeutic methods, such as TKI and PD-1 inhibitor, may be a better choice.
Bridging therapy is another important application of TACE noted in liver transplantation . TACE achieved higher DCR in the present study (90.9%), which ensured that it could be widely used in bridging therapy of liver transplantation compared with downstaging. Other studies have also confirmed this conclusion. The LT reported for the bridging group was 66% while the downstaging was 34% .
Not all patients with CR can reach PCR and the proportion of PCR in CR is approximately 54.2-76% [28,29]. This percentage was estimated to 33.3% in the present study and therefore the surgery was still recommended for CR patients. However, the question still remains of whether surgery is necessary for patients with PCR. It is difficult to find a definite answer due to the lack of the sensitive and specific standard for PCR diagnosis following TACE. That is to say, we cannot accurately judge whether the patient experiences PCR or not prior to removal of the tumor. In addition, even if there is a standard for accurate diagnosis of PCR, long-term follow-up and further comparative studies are still required to address this question.
TACE may increase the difficulty of operation by causing abdominal adhesion and arterial injury . However, this influence is acceptable. In the present study, all abdominal adhesion cases were mild adhesions and easy to separate. Based on the successful application of arterial anastomosis technology, no arterial complications occurred even in liver transplantation patients with hepatic artery injury.