The Relationship Between Tamoxifen-associated Nonalcoholic Fatty Liver Disease and the Prognosis of Patients With Early-stage Breast Cancer

Vitamin D inhibits tamoxifen-induced non-alcoholic fatty liver disease through a nonclassical estrogen receptor/liver X receptor pathway

Non-alcoholic Fatty Liver Disease (NAFLD) is one of the common side effects of tamoxifen treatment for estrogen receptor-positive breast cancer, and is representative of disorders of energy metabolism. Fatty liver is induced after tamoxifen (TAM) inhibition of estrogen receptor activity, but the exact mechanism is not clear. This study investigated the effects and mechanisms of TAM-induced steatosis in the liver. The effects and mechanisms of TAM on hepatocyte lipid metabolism were assessed using C57BL/6 female mice and human hepatoma cells. TAM promoted fat accumulation in the liver by upregulation of Srebp-1c expression. Regarding the molecular mechanism, TAM promoted the recruitment of the auxiliary transcriptional activator, p300, and dissociated the auxiliary transcriptional repressor, nuclear receptor corepressor (NCOR), of the complexes, which led to enhancement of Srebp-1c transcription and an increase of triglyceride (TG) synthesis. Vitamin D (VD), a common fat-soluble vitamin, can decrease TAM-induced NAFLD by promoting p300 dissociation and NCOR recruitment. Tamoxifen promoted the recruitment and dissociation of co-transcription factors on the LXR/ER/RXR receptor complex, leading to a disorder of liver lipid metabolism. VD interfered with TAM-induced liver lipid metabolism disorders by reversing this process.

Extrahepatic Outcomes of Nonalcoholic Fatty Liver Disease: Nonhepatocellular Cancers

Nonalcoholic fatty liver disease (NAFLD) encompasses the entire spectrum of fatty liver disease in individuals without significant alcohol consumption, including isolated steatosis, steatohepatitis, and cirrhosis. The overall global prevalence of NAFLD is estimated to be 30%, and the associated clinical and economic burden will continue to increase. NAFLD is a multisystemic disease with established links to cardiovascular disease, type 2 diabetes, metabolic syndrome, chronic kidney disease, polycystic ovarian syndrome, and intra- and extrahepatic malignancies. In this article the authors review the potential mechanisms and current evidence for the association between NAFLD and extrahepatic cancers and the resultant impact on clinical outcomes.

Identification of Hub Genes and Biological Mechanisms Associated with Non-Alcoholic Fatty Liver Disease and Triple-Negative Breast Cancer

The relationship between non-alcoholic fatty liver disease (NAFLD) and triple-negative breast cancer (TNBC) has been widely recognized, but the underlying mechanisms are still unknown. The objective of this study was to identify the hub genes associated with NAFLD and TNBC, and to explore the potential co-pathogenesis and prognostic linkage of these two diseases. We used GEO, TCGA, STRING, ssGSEA, and Rstudio to investigate the common differentially expressed genes (DEGs), conduct functional and signaling pathway enrichment analyses, and determine prognostic value between TNBC and NAFLD. GO and KEGG enrichment analyses of the common DEGs showed that they were enriched in leukocyte aggregation, migration and adhesion, apoptosis regulation, and the PPAR signaling pathway. Fourteen candidate hub genes most likely to mediate NAFLD and TNBC occurrence were identified and validation results in a new cohort showed that ITGB2, RAC2, ITGAM, and CYBA were upregulated in both diseases. A univariate Cox analysis suggested that high expression levels of ITGB2, RAC2, ITGAM, and CXCL10 were associated with a good prognosis in TNBC. Immune infiltration analysis of TNBC samples showed that NCF2, ICAM1, and CXCL10 were significantly associated with activated CD8 T cells and activated CD4 T cells. NCF2, CXCL10, and CYBB were correlated with regulatory T cells and myeloid-derived suppressor cells. This study demonstrated that the redox reactions regulated by the NADPH oxidase (NOX) subunit genes and the transport and activation of immune cells regulated by integrins may play a central role in the co-occurrence trend of NAFLD and TNBC. Additionally, ITGB2, RAC2, and ITGAM were upregulated in both diseases and were prognostic protective factors of TNBC; they may be potential therapeutic targets for treatment of TNBC patients with NAFLD, but further experimental studies are still needed.

Postdiagnosis body fatness, weight change and breast cancer prognosis: Global Cancer Update Program (CUP global) systematic literature review and meta-analysis

Previous evidence on postdiagnosis body fatness and mortality after breast cancer was graded as limited-suggestive. To evaluate the evidence on body mass index (BMI), waist circumference, waist-hip-ratio and weight change in relation to breast cancer prognosis, an updated systematic review was conducted. PubMed and Embase were searched for relevant studies published up to 31 October, 2021. Random-effects meta-analyses were conducted to estimate summary relative risks (RRs). The evidence was judged by an independent Expert Panel using pre-defined grading criteria. One randomized controlled trial and 225 observational studies were reviewed (220 publications). There was strong evidence (likelihood of causality: probable) that higher postdiagnosis BMI was associated with increased all-cause mortality (64 studies, 32 507 deaths), breast cancer-specific mortality (39 studies, 14 106 deaths) and second primary breast cancer (11 studies, 5248 events). The respective summary RRs and 95% confidence intervals per 5 kg/m2 BMI were 1.07 (1.05-1.10), 1.10 (1.06-1.14) and 1.14 (1.04-1.26), with high between-study heterogeneity (I2  = 56%, 60%, 66%), but generally consistent positive associations. Positive associations were also observed for waist circumference, waist-hip-ratio and all-cause and breast cancer-specific mortality. There was limited-suggestive evidence that postdiagnosis BMI was associated with higher risk of recurrence, nonbreast cancer deaths and cardiovascular deaths. The evidence for postdiagnosis (unexplained) weight or BMI change and all outcomes was graded as limited-no conclusion. The RCT showed potential beneficial effect of intentional weight loss on disease-free-survival, but more intervention trials and well-designed observational studies in diverse populations are needed to elucidate the impact of body composition and their changes on breast cancer outcomes.

Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Tamoxifen induced hepatic steatosis in high-fat feeding rats through SIRT1-Foxo1 suppression and LXR-SREBP1c activation

Background

Clinically, long-term use of tamoxifen (TAM) would lead to fatty liver disease in breast cancer patients, especially obese women. However, the exact mechanism of TAM-induced hepatic steatosis is still unclear. Meanwhile, there is no drug to prevent and treat it.

Aims and Methods

In view of silent information regulator 1 (SIRT1) playing a key role in hepatic lipid metabolism regulation, this study was conducted to investigate whether SIRT1 is a potential therapeutic target for TAM-induced hepatic steatosis. In this study, obese female Wistar rats fed with high-fat diet (HFD) for 15 weeks were given TAM (4, 8 mg/kg, intragastric) for 14 days. In vitro, human hepatocarcinoma cell line HepG2 was used to establish a high-fat model with 50 μM oleic acid and TAM (10 μM) was treated simultaneously for 72 h.

Results

The results showed that TAM was more likely to upregulate the expression of lipid synthetase that caused the increase of lipid content in HepG2 cells and rat liver. The expression of SIRT1 was downregulated both in vitro and in vivo. SIRT1 agonist SRT1720 (15 mg/kg, 30 mg/kg, i.p.) could resist TAM-induced hepatic lipid synthetase overexpression to relieve TAM-induced hepatic steatosis. Meanwhile, the upregulation of p-forkhead box O1 and LXRα induced by TAM was reversed by SRT1720.

Conclusions

These results indicated that TAM-induced hepatic steatosis was based on SIRT1-p-FoxO/LXRα-sterol regulatory element binding protein 1c pathway under HFD condition. SIRT1 agonist might be a potential therapeutic drug to relieve this side effect.

Highlights

Tamoxifen increased lipid synthesis and regulated lipid transport in HFD rat liver.p-FoxO1/LXRα-SREBP1c signaling was upregulated through the inhibition of SIRT1 in tamoxifen-induced hepatic steatosis under HFD condition.SIRT1 agonist SRT1720 could relieve tamoxifen-induced hepatic steatosis.

Fatty Liver in Hormone Receptor-Positive Breast Cancer and Its Impact on Patient's Survival

Purpose

Long-term estrogen inhibition may cause fatty liver disease (non-alcoholic fatty liver disease; NAFLD) among other adverse conditions such as osteoporosis, climacteric symptoms, thromboembolism, dyslipidemia, and metabolic syndrome. The prevalence of NAFLD among breast cancer patients ranges from 2.3%–45.2%. This study aimed to determine the risk factors for newly developed NAFLD among breast cancer patients after hormonal treatment and whether it influences survival outcomes.

Methods

This retrospective study investigated hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2−), nonmetastatic breast cancer patients diagnosed between January 2010 and December 2018. All patients received adjuvant hormonal treatment for at least 6 months. Clinical data on metabolic profile indicators such as body mass index (BMI), waist circumference, serum cholesterol, triglycerides, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), diabetes, and presence of metabolic syndrome (MetS) were collected. In total, 160 eligible patients with complete covariate data and survival follow-up were included.

Results

NAFLD was diagnosed in 35% of patients. There were significant associations of being overweight (BMI ≥ 25 kg/m²), waist circumference > 80 cm, triglycerides ≥ 150 mg/dL, HDL-C ≤ 50 mg/dL, LDL-C < 150 mg/dL, and presence of MetS with the development of NAFLD. However, unlike other factors, MetS and HDL-C were not independently associated with NAFLD. Patients with breast cancer who developed NAFLD had longer disease-free survival (DFS). The median DFS was not reached in the NAFLD group, whereas it was 59.3 (45.6–73.0) months in the non-NAFLD group. No worsening of overall survival was observed in patients with breast cancer and NAFLD.

Conclusion

The development of NAFLD during treatment in patients with HR+/HER2− breast cancer was associated with several independent risk factors: being overweight, waist circumference, triglycerides, and LDL-C. Interestingly, breast cancer patients with NAFLD during treatment had longer DFS than those without NAFLD.

Prevalence, incidence and risk factors of tamoxifen-related non-alcoholic fatty liver disease: A systematic review and meta-analysis

BACKGROUND & AIMS

Tamoxifen is associated with an increased risk of developing fatty liver. The aim of this systematic review and meta-analysis was to evaluate the prevalence and incidence of fatty liver developed after tamoxifen treatment in breast cancer patients.

METHODS

A systematic search of PubMed (Medline), EMBASE, OVID Medline, the Cochrane Library and other databases was performed for this review. The abstracts obtained from the search were reviewed by two investigators who chose manuscripts for full-text review. The event rates were calculated with a random-effects model and quality-effects model.

RESULTS

The search yielded 165 references. Of these, 24 were included in the quantitative summary. We analysed the data of a total of 6,962 patients treated with tamoxifen and 975 patients not treated with tamoxifen. The prevalence of fatty liver among patients with breast cancer taking tamoxifen was 40.25 per 100 patients and the incidence rate was 12.37 per 100 person-years. The incidence of fatty liver was much higher in the tamoxifen group than in the control group [incidence rate ratio: 3.12, 95% CI (confidence interval): 2.05-4.75, I²  = 61%], regardless of region. The main risk factors were body mass index (BMI) [hazard ratio (HR): 1.15, 95% CI: 1.09-1.22] and hypercholesterolaemia (HR: 1.01, 95% CI: 1.00-1.02).

CONCLUSION

The use of tamoxifen was associated with increased risks in the incidence and prevalence of fatty liver, especially in patients with high BMI and hypercholesterolaemia.

The impact of pre-existed and SERM-induced non-alcoholic fatty liver disease on breast cancer survival: a meta-analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is a common disorder and a frequent side effect of endocrine therapy (ET) for breast cancer treatment. This was the first meta-analysis to investigate the impact of NAFLD on breast cancer survival.

Material and Methods: We searched Pubmed, Embase and Cochrane Central Register of Controlled Trials database for relevant studies that investigated the correlation between NAFLD and breast cancer survival. Fixed- and random-effect meta-analyses were conducted according to the heterogeneity of enrolled studies. Subgroup analyses were performed based on whether NAFLD was induced by ET administration

Results: Eight cohorts from six studies including 3684 breast cancer patients were enrolled. NAFLD was significantly associated with advanced age (p < 0.001), obesity (p < 0.001), lymph node metastases (p = 0.003) and hormone receptor positivity (p < 0.001). NAFLD had no significant impact on disease free survival (DFS) [hazard ratio (HR) 1.07, 95% confidence interval (CI) = 0.64-1.77, p = 0.81] and overall survival (OS) (HR 1.29, 95% CI = 0.68-2.44, p = 0.44). In subgroup analyses, ET-associated NAFLD showed no significant impact on DFS and OS. Nonetheless, non-ET-associated NAFLD had a strong prognostic correlation with poor OS (HR 1.92, 95% CI = 1.09-3.41, p = 0.02).

Conclusion: NAFLD had no significant impact on breast cancer survival. However, non-ET-associated NAFLD implied increasing death risk. Future large-scale studies are warranted to further elucidate the correlation between NAFLD and breast cancer prognosis.

Recurrence pattern in the presence of hepatosteatosis in breast cancer: does it facilitate liver metastasis?

Aim: We aimed to investigate the impact of hepatosteatosis (HS) severity on the recurrence pattern of breast cancer and to clarify whether HS causes affinity to recurrence with liver metastasis. Materials & methods: The median follow-up was 80.0 (4-217) months and the mean age was 47.9 ± 11.3 years. Among all, 181 (39.9%) patients were diagnosed with grades 2 and 3 HS. Of total, 158 (34.8%) patients have experienced recurrence. Results: While higher degree of HS was more common in patients presented with liver recurrence (odds ratio; 95% CI: 2.50; 1.27-4.92; p = 0.007), it was lesser in those with other metastatic sites (all were >0.05). Liver-recurrence-free survival was significantly worse in the group with higher degree of HS (hazard ratio; 95% CI: 2.46; 1.4-4.3; p = 0.002) together with younger age (hazard ratio; 95% CI: 2.44; 1.4-4.3; p = 0.002) in multivariate analysis. Conclusion: HS might have produced an affinity for liver metastasis in common types of breast cancer patients in remission independent from metabolic disorders or clinicopathologic features.

Tamoxifen-induced hepatotoxicity via lipid accumulation and inflammation in zebrafish

Tamoxifen is a clinical drug for estrogen receptor (ER)-positive breast cancer. Recently, it has been detected in aquatic environment. The residual drugs will produce certain biological activity and create a risk to aquatic organism when they enter the water environment. Therefore, it has great significance to study the ecotoxicity of tamoxifen. In the study, we used zebrafish as a model of aquatic to investigate the ecotoxic mechanism of tamoxifen to aquatic. We found that tamoxifen induced liver lipid accumulation in zebrafish, which showed a significant hepatotoxicity with smaller liver area and bigger yolk area. Though biochemical and pathologic measurement, tamoxifen treated group showed higher transaminase and lipid content. The elevated liver lipid synthesis might due to the increase of lipid metabolism related gene Srebf1, Srebf2 and Fasn. Moreover, inflammatory cytokine Tnf-α, Il-1β And Il-6 were increased. This result confirmed the toxicity of tamoxifen to aquatic, suggested liver injury was the main characteristic of its ecotoxicity. This study indicated it is important to avoid tamoxifen discharging into the aquatic ecology and provided a theoretical basis of prevention tamoxifen-induced ecotoxicity to aquatic.

Aromatase Inhibitors and Newly Developed Nonalcoholic Fatty Liver Disease in Postmenopausal Patients with Early Breast Cancer: A Propensity Score-Matched Cohort Study

BACKGROUND

Unlike tamoxifen, the relationship between aromatase inhibitor use in postmenopausal patients with breast cancer and nonalcoholic fatty liver disease (NAFLD) has not been delineated.

MATERIALS AND METHODS

A retrospective analysis of 253 patients with early breast cancer without baseline NAFLD and treated with nonsteroidal aromatase inhibitors was performed. Among them, 220 patients were matched for sex, age, and menstruation status with healthy patients, and the prevalence of NAFLD was compared. NAFLD was determined by hepatic steatosis index in the absence of other known liver diseases. The presence of significant liver fibrosis in patients with NAFLD was determined noninvasively by AST-platelet ratio index, FIB-4 score, and NAFLD fibrosis score (NFS).

RESULTS

Postmenopausal patients with breast cancer undergoing treatment with aromatase inhibitors had higher prevalence of NAFLD independent of body mass index (BMI) and underlying diabetes mellitus (DM). Although the aromatase inhibitor group showed higher fibrotic burden by NFS, independent of BMI and DM, the proportion of advanced fibrosis did not show statistically significant differences between AI-treated patients and the healthy patients. Those with abnormal baseline fasting glucose levels are suggested to have increased risk of NAFLD development after aromatase inhibitor treatment. In addition, patients with NAFLD developed after aromatase inhibitor use had significantly lower disease-free survival than those without NAFLD, although there was no significant difference in overall survival.

CONCLUSION

Results of this study suggest that inhibition of estrogen synthesis in postmenopausal women undergoing treatment with aromatase inhibitors could increase the risk of NAFLD, which might have some influence on the prognosis of patients with breast cancer.

IMPLICATIONS FOR PRACTICE

Unlike tamoxifen, the role of aromatase inhibitor treatment use in postmenopausal patients with breast cancer in development of fatty liver is not well known. In this propensity-matched cohort study, postmenopausal patients with breast cancer treated with aromatase inhibitors had increased risk of nonalcoholic fatty liver disease compared with healthy women after menopause, independent of obesity and diabetes mellitus. The results show possible adverse influence of the newly developed fatty liver on breast cancer disease-free survival and suggest a necessity for further validation. Fatty liver may need to be considered as an adverse event for aromatase inhibitor treatment.