Megestrol Acetate in Unresectable Hepatocellular Carcinoma

Systemic Management for Advanced Hepatocellular Carcinoma: A Review of the Molecular Pathways of Carcinogenesis, Current and Emerging Therapies, and Novel Treatment Strategies

Hepatocellular carcinoma (HCC) arises from a number of cirrhosis-related and non-cirrhosis-related exposures and is one of the leading causes of cancer-related deaths worldwide. Achieving a durable cure currently relies on either resection or transplantation, but since most patients will be diagnosed with inoperable disease, there is great interest in achieving more effective systemic therapies. At a molecular level, HCC is heterogeneous, but initial treatment strategies, including the use of multi-targeted tyrosine kinase inhibitors and checkpoint inhibitors, have been fairly homogenous, depending on general host factors and overall tumor burden rather than specific molecular signatures. Over the past 2 decades, however, there has been significant success in identifying key molecular targets, including driver mutations involving the telomerase reverse transcriptase, p53, and beta-catenin genes, and significant work is now being devoted to translating these discoveries into the development of robust and well-tolerated targeted therapies. Furthermore, multi-modal therapies have also begun to emerge, harnessing possible synergism amongst a variety of different treatment classes. As the findings of these landmark trials become available over the next several years, the landscape of the systemic management of advanced HCC will change significantly.

Androgen receptor (AR) differential roles in hormone-related tumors including prostate, bladder, kidney, lung, breast and liver

The androgen receptor (AR) is expressed in many cell types and the androgen/AR signaling has been found to have important roles in modulating tumorigenesis and metastasis in several cancers including prostate, bladder, kidney, lung, breast and liver. However, whether AR has differential roles in the individual cells within these tumors that contain a variety of cell types remains unclear. Generation of AR knockout (ARKO) mouse models with deletion of AR in selective cells within tumors indeed have uncovered many unique AR roles in the individual cell types during cancer development and progression. This review will discuss the results obtained from various ARKO mice and different human cell lines with special attention to the cell type- and tissue-specific ARKO models. The understanding of various results showing the AR indeed has distinct and contrasting roles in each cell type within many hormone-related tumors (as stimulator in bladder, kidney and lung metastases vs as suppressor in prostate and liver metastases) may eventually help us to develop better therapeutic approaches by targeting the AR or its downstream signaling in individual cell types to better battle these hormone-related tumors in different stages.

Randomised double-blind trial of megestrol acetate vs placebo in treatment-naive advanced hepatocellular carcinoma

Background:

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide. We tested megestrol acetate (MA) against placebo in the treatment of advanced HCC.

Methods:

From 2002 through 2007, this randomised double-blind trial enrolled 204 patients with treatment-naive advanced HCC (Eastern Cooperative Oncology Group (ECOG) performance rating of 0-3) from specialist care centres in six Asia-Pacific nations. Patients received placebo or MA (320 mg day⁻¹). End points were overall survival (OS) and quality of life.

Results:

An adverse but not statistically significant difference in OS was found for MA vs placebo: median values 1.88 and 2.14 months, respectively (hazard ratio (HR)=1.25, 95% CI=0.92–1.71, P=0.16). However, OS was similar among patients of good functional status (Child-Pugh A and ECOG 0, 1 or 2) (44.3%) in both treatment groups, with the adverse effect of MA confined to those of poor status. Megestrol acetate patients had a worse global health status (not statistically significant) but reduced levels of appetite loss and nausea/vomiting.

Conclusion:

Megestrol acetate has no role in prolonging OS in advanced treatment-naive HCC. Overall survival with placebo differed markedly from that in similar trials conducted elsewhere, suggesting therapeutic outcomes may be strongly dependent on ECOG status and Child-Pugh score.

The role for estrogen receptor-alpha and prolactin receptor in sex-dependent DEN-induced liver tumorigenesis

Mice treated neonatally with diethylnitrosamine (DEN) develop liver tumors in a male-dominant manner, reflecting the male bias in human hepatocellular carcinoma. Evidence suggests that estrogen, androgen, prolactin (PRL) and growth hormone (GH) modify liver tumorigenesis. We determined the roles of estrogen receptor-α (ERα) and prolactin receptor (PRLR) using receptor null mice, ERαKO (C57Bl/6J) and PRLR-KO (129Ola-X-C57BL/6), in the neonatal-DEN model of liver tumorigenesis. In both mouse strains, females had reduced tumorigenesis compared with males (P < 0.01), regardless of ERα or PRLR status. Tumorigenesis was not affected by ovariectomy in C57Bl/6J mice but it was increased by ovariectomy in the mixed strain, 129Ola-X-C57BL/6, regardless of PRLR status. ERαKO males had 47% fewer tumors than ERα wild-type males (P < 0.01). On the other hand, estradiol treatment protected against tumorigenesis in males only in the presence of ERα. As evidenced by liver gene expression, lack of ERα did not alter the pattern of GH secretion in males but resulted in the male GH pattern in females. These observations indicate that ERα is not required for lower tumorigenesis in females, but it is required for the protective effects of exogenously delivered estradiol. Unexpectedly, the results indicate that ERα plays a role in promotion of liver tumors in males. In addition, it can be concluded that sex differences in liver tumorigenesis cannot be explained by the sexually dimorphic pattern of GH secretion. The results also rule out PRL as the mediator of the protective effect of the ovaries.

Hepatocellular carcinoma associated with liver-gender disruption in male mice

Hepatocellular carcinoma (HCC) is a male-predominant cancer associated with chronic hepatitis. Like human viral hepatitis, murine Helicobacter hepaticus infection produces inflammation and HCC with a masculine bias. We used this model to identify potential mechanisms of male HCC predisposition. Male weanling A/JCr mice (n = 67) were gavaged with H. hepaticus or vehicle. At 1 year, mice were distributed into four groups: surgical castration, chemical castration, castration followed by dihydrotestosterone supplementation, or sexually intact controls. Responses to infection were compared with IFN-gamma challenge alone. At 21 months, there was no significant difference in hepatitis between groups. Neither castration nor androgen receptor agonism altered tumor incidence. Infected mice with severe, but not mild, disease exhibited a mosaic of alterations to sexually dimorphic genes and microsomal long-chain fatty acids. By microarray, tumorigenic hepatitis was strongly associated with liver-gender disruption, defined as the loss of a gender-identifying hepatic molecular signature. IFN-gamma alone produced similar changes, demonstrating a role for proinflammatory cytokines in this process. In conclusion, hepatocarcinogenesis in male mice with chronic hepatitis is maturationally imprinted and androgen-independent. Proinflammatory cytokines may promote HCC in a male-predominant fashion due to high sensitivity of the masculinized liver to loss of sex-specific transcriptional balance. Liver-gender disruption has pleiotropic implications for hepatic enzyme activity, lipid processing, nuclear receptor activation, apoptosis, and proliferation. We propose a multistep model linking chronic hepatitis to liver cancer through cytokine-mediated derangement of gender-specific cellular metabolism. This model introduces a novel mechanism of inflammation-associated carcinogenesis consistent with male-predominant HCC risk.

Systemic therapy for advanced hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) is a common cause of cancer mortality worldwide. Whilst local treatments are useful in selected patients, they are not suitable for many with advanced disease. Here, we review phase II and III trials for systemic therapy of advanced disease, finding no strong evidence that any chemotherapy, hormonal therapy, or immunotherapy regimen trialled to date benefits survival in this setting. Many trials were inadequately powered, single centre, and enrolled highly selected patients. From this review, we cannot recommend any therapeutic approach in these patients outside of a clinical trial setting. Including an untreated control arm in clinical trials in HCC is still justified. Every effort should be made to enroll these patients into adequately powered trials, and promising phase II results must be tested in a multicentre phase III setting, preferably against a placebo control arm. Prevention of hepatitis B and C remains vital to decrease deaths from HCC.

Endocrine treatment of hepatocellular carcinoma. Any evidence of benefit?

In the past 20 years, a number of studies have investigated the relationship between sex hormones and liver cancer. Experimental studies indicate that a dynamic process, with sequential modifications in the pattern of sex hormones in the serum and of sex hormone receptors in the liver, occurs progressively during hepatocarcinogenesis. Overall, it seems that both androgens and oestrogens may enhance liver carcinogenesis, while androgens may also support the growth of established liver tumours. Unfortunately, clinical studies of endocrine treatment of hepatocellular carcinoma (HCC) have not adequately tested the suggestions from biological studies. So far, no clinical trial has been performed to test the efficacy of endocrine manipulation for the chemoprevention of HCC in cirrhotic patients nor in preventing relapse after radical resection of primary HCC. Anti-oestrogens have been the most studied agents for the endocrine treatment of established HCC, although the rationale that supports their use is weaker than for anti-androgens. Studies with anti-androgens have produced prevalently negative results, due to either a lack of activity or excessive toxicity. The use of chemical castration, which theoretically could enhance the activity of antihormonal compounds, yielded no benefit at all. In summary, there is, as yet, no definitive evidence that endocrine treatment favourably affects the outcome of patients with HCC.