Assessment of non-surgical versus surgical therapy for localized hepatocellular carcinoma

Stimulus-responsive self-assembled prodrugs in cancer therapy

Small-molecule prodrugs have become the main toolbox to improve the unfavorable physicochemical properties of potential therapeutic compounds in contemporary anti-cancer drug development. Many approved small-molecule prodrugs, however, still face key challenges in their pharmacokinetic (PK) and pharmacodynamic (PD) properties, thus severely restricting their further clinical applications. Self-assembled prodrugs thus emerged as they could take advantage of key benefits in both prodrug design and nanomedicine, so as to maximize drug loading, reduce premature leakage, and improve PK/PD parameters and targeting ability. Notably, temporally and spatially controlled release of drugs at cancerous sites could be achieved by encoding various activable linkers that are sensitive to chemical or biological stimuli in the tumor microenvironment (TME). In this review, we have comprehensively summarized the recent progress made in the development of single/multiple-stimulus-responsive self-assembled prodrugs for mono- and combinatorial therapy. A special focus was placed on various prodrug conjugation strategies (polymer-drug conjugates, drug-drug conjugates, etc.) that facilitated the engineering of self-assembled prodrugs, and various linker chemistries that enabled selective controlled release of active drugs at tumor sites. Furthermore, some polymeric nano-prodrugs that entered clinical trials have also been elaborated here. Finally, we have discussed the bottlenecks in the field of prodrug nanoassembly and offered potential solutions to overcome them. We believe that this review will provide a comprehensive reference for the rational design of effective prodrug nanoassemblies that have clinic translation potential.

Bridging the preoperative gap of precision hepatectomy: Superstable homogeneous iodinated formulation technology

The in-situ post-embolization fluorescence-guided hepatectomy for hepatocellular carcinoma (HCC) requires precise embolic formulation that meets both preoperative and intraoperative needs of hepatobiliary surgeons. In this Editorial, we highlight the development of Superstable Homogeneous Iodinated Formulation Technology (SHIFT) for locoregional HCC treatment. It is believed that such an intelligent solution could resolve unmet formulation needs and make a major stride to bridge the preoperative gap of precision hepatectomy.

Dimeric prodrug-based nanomedicines for cancer therapy

With the rapid development of conjugation chemistry and biomedical nanotechnology, prodrug-based nanosystems (PNS) have emerged as promising drug delivery nanoplatforms. Dimeric prodrug, as an emerging branch of prodrug, has been widely investigated by covalently conjugating two same or different drug molecules. In recent years, great progress has been made in dimeric prodrug-based nanosystems (DPNS) for cancer therapy. Many advantages offered by DPNS have significantly facilitated the delivery efficiency of anticancer drugs, such as high drug loading capacity, favorable pharmacokinetics, tumor stimuli-sensitive drug release and facile combination theranostics. Given the rapid developments in this field, we here outline the latest updates of DPNS in cancer treatment, focusing on dimeric prodrug-encapsulated nanosystems, dimeric prodrug-nanoassemblies and tumor stimuli-responsive DPNS. Moreover, the design principle, advantages and challenges of DPNS for clinical cancer therapy are also highlighted.

A superstable homogeneous lipiodol-ICG formulation for locoregional hepatocellular carcinoma treatment

Accurate identification of surgical margins for malignancy remains a challenge in the surgical therapy of cancer, and this encountered interoperative difficulties which directly contribute to the prognosis of patients. In recent years, indocyanine green (ICG) has been approved and applied in clinical settings for lesions detection, especially for the precise surgical resection. However, rapid clearance and poor stability greatly limit its clinical practicality. Herein, a super-stable homogeneous iodinated formulation technology (SHIFT) is designed to realize sufficient dispersion of ICG into lipiodol (SHIFTs) for transcatheter embolization (TAE) synergistic fluorescence-guided resection. Particularly, SHIFTs is prepared in a green physical mixture via a carrier-free manner, which possesses controlled morphology, long-term stability, and improved optical characteristics of ICG (fluorescence/photoacoustic/photothermal activities). Furthermore, the viscosity of the synthetic solvent is comparable to lipiodol, and further assessment demonstrated the same efficacy in computed tomography. The performance of SHIFTs in the fluorescence navigation was further evaluated in vivo by TAE therapy to the rabbit VX2 tumor model for a two-week monitor. The integration of near-infrared fluorescence surgery navigation and TAE could effectively guarantee the precise resection for hepatocellular carcinoma. This SHIFT system provides good potentials for ameliorating the dilemma of precise fluorescent navigation for surgical resection after arterial embolization in clinical practice.

Minimally Invasive Liver Resection for Early-Stage Hepatocellular Carcinoma: Inconsistent Outcomes from Matched or Weighted Cohorts

BACKGROUND

The aim of the current study was to re-evaluate the role of minimally invasive liver resection (MILR) among patients with early-stage (stage I or II) hepatocellular carcinoma (HCC) undergoing partial hepatectomy.

METHODS

A retrospective analysis of the National Cancer Database (NCDB) was conducted to identify patients with early-stage HCC who underwent partial hepatectomy in the USA from 2010 to 2013. Overall survival (OS) was compared in three cohorts: crude; stabilized inverse probability of treatment propensity score weighting (IPTW); and propensity score matching (PSM).

RESULTS

Among 4027 patients included in the study, only 11.7%, (n = 473) underwent MILR. In the stabilized IPTW cohort, patients who underwent MILR versus open resection were more likely to have tumors greater than 3 cm (63.9%, n = 285 vs. 51.4%, n = 228, p < 0.001) and poorly/undifferentiated tumors (21.5%, n = 96 vs. 12.9%, n = 57, p < 0.001). Within the crude cohort, a 5-year OS was superior among patients in the open surgical group (67.8%) compared with patients who underwent MILR (56.6%) (p < 0.001). After classic PSM analysis, the 5-year OS of patients undergoing MILR and open surgery were noted to be comparable (57.3% vs 63.8%, p = 0.17; HR 1.16, 95% CI 0.92-1.45). In contrast, after applying IPTW, the 5-year OS of patients who underwent MILR (55.5%) was worse compared with patients who had an open resection (67.5%) (HR 1.46, 95% CI 1.15-1.84; p < 0.001).

CONCLUSIONS

Long-term outcomes of patients undergoing MILR were comparable with patients who had open surgery when assessed by standard PSM. The use of IPTW resulted in more unbalanced groups leading to residual confounding and bias.

Angiosomal radiopathologic analysis of transarterial radioembolization for the treatment of hepatocellular carcinoma

PURPOSE

To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response.

METHODS

Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features.

RESULTS

Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN.

CONCLUSIONS

The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.

Liver transplant offers a survival benefit over margin negative resection in patients with small unifocal hepatocellular carcinoma and preserved liver function

BACKGROUND

Studies comparing orthotopic liver transplantation to margin negative resection for patients with small unifocal hepatocellular carcinoma have not controlled for degree of cirrhosis.

METHODS

The National Cancer Database was used to identify patients with preserved liver function (Model for End-stage Liver Disease score ≤12) who underwent orthotopic liver transplantation or margin negative resection for American Joint Committee on Cancer stage I hepatocellular carcinoma lesions <3 cm between 2010 and 2013. Multivariable and Cox regression adjusting for age, demographics, comorbid disease burden, Model for End-stage Liver Disease score, tumor size, and operation were used to compare overall survival between cohorts.

RESULTS

In the study, 241 (53%) patients underwent orthotopic liver transplantation. In addition, 219 (47%) underwent margin negative resection. On multivariable regression, patients having a Charlson comorbidity score ≥2 were more likely to undergo orthotopic liver transplantation, (odds ratio 1.94, P=.03). African American patients (odds ratio 0.44, P=.02), and patients of advanced age (odds ratio 0.92, P<.001) were more likely to undergo margin negative resection. Patients undergoing orthotopic liver transplantation had longer overall survival than those undergoing margin negative resection (median OS not reached versus 67.6 months, P<.001). Multivariable Cox regression identified surgical procedure as the only independent determinant of survival with margin negative resection conferring a nearly 3-fold increased risk of death (hazard ratio 2.86, P<.001).

CONCLUSION

Orthotopic liver transplantation offers a survival advantage relative to margin negative resection for patients with small unifocal hepatocellular carcinoma and preserved liver function.

Competing risk analysis on outcome after hepatic resection of hepatocellular carcinoma in cirrhotic patients

AIM

To investigate death for liver failure and for tumor recurrence as competing events after hepatectomy of hepatocellular carcinoma.

METHODS

Data from 864 cirrhotic Child-Pugh class A consecutive patients, submitted to curative hepatectomy (1997-2013) at two tertiary referral hospitals, were used for competing-risk analysis through the Fine and Gray method, aimed at assessing in which circumstances the oncological benefit from tumour removal is greater than the risk of dying from hepatic decompensation. To accomplish this task, the average risk of these two competing events, over 5 years of follow-up, was calculated through the integral of each cumulative incidence function, and represented the main comparison parameter.

RESULTS

Within a median follow-up of 5.6 years, death was attributable to tumor recurrence in 63.5%, and to liver failure in 21.2% of cases. In the first 16 mo, the risk of dying due to liver failure exceeded that of dying due to tumor relapse. Tumor stage only affects death from recurrence; whereas hepatitis C infection, Model for End-stage Liver Disease score, extent of hepatectomy and portal hypertension influence death from liver failure (P < 0.05 in all cases). The combination of these clinical and tumoral features identifies those patients in whom the risk of dying from liver failure did not exceed the tumour-related mortality, representing optimal surgical candidates. It also identifies those clinical circumstances where the oncological benefit would be borderline or even where the surgery would be harmful.

CONCLUSION

Having knowledge of these competing events can be used to weigh the risks and benefits of hepatic resection in each clinical circumstance, separating optimal from non-optimal surgical candidates.