Interactions Between ABCB1 Genotype and Preoperative Statin Use Impact Clinical Outcomes Among Breast Cancer Patients

Impact of statin use on breast cancer recurrence and mortality before and after diagnosis: a systematic review and meta-analysis

Objective

Breast cancer is one of the most common causes of death among women. Statins, typically used for cholesterol management, have been hypothesized to reduce recurrence and mortality rates in breast cancer. However, this association remains a subject of debate. This study evaluates the potential impact of statins on breast cancer recurrence and mortality.

Methods

A comprehensive search was conducted in the PubMed, EMBASE, and Cochrane databases for articles published up to June 2023. These articles examined the effect of statins on breast cancer recurrence and mortality both before and after diagnosis. The analysis was performed using random-effects models, calculating pooled hazard ratios (HR) and their 95% confidence intervals (CI).

Results

A total of 31 cohort studies, involving 261,834 female breast cancer patients, were included in this analysis. It was found that statin use prior to diagnosis was associated with a decrease in overall mortality (HR, 0.8; 95% CI, 0.69-0.93; I2 = 77.6%; P = 0.001) and breast cancer-specific mortality (HR, 0.76; 95% CI, 0.67-0.87; I2 = 72.7%; P = 0.005). Additionally, statin use after diagnosis was observed to reduce the recurrence of breast cancer (HR, 0.71; 95% CI, 0.61-0.82; I2 = 60%; P = 0.003), overall mortality (HR, 0.81; 95% CI, 0.70-0.92; I2 = 80.7%; P < 0.001), and breast cancer-specific mortality (HR, 0.76; 95% CI, 0.67-0.86; I2 = 74.5%; P < 0.001).

Conclusions

The findings of this study indicate that statin usage, both before and after breast cancer diagnosis, may be associated with reduced risks of overall and breast cancer-specific mortality, as well as lower recurrence rates.

Post-diagnostic statin use and breast cancer-specific mortality: a population-based cohort study

PURPOSE

Statins are the most widely prescribed cholesterol lowering medications and have been associated with both improved and unchanged breast cancer outcomes in previous studies. This study examines the association between the post-diagnostic use of statins and breast cancer outcomes (death and recurrence) in a large, representative sample of New Zealand (NZ) women with breast cancer.

METHODS

Women diagnosed with a first primary breast cancer between 2007 and 2016 were identified from four population-based regional NZ breast cancer registries and linked to national pharmaceutical data, hospital discharges, and death records. Cox proportional hazard models were used to estimate the hazard of breast cancer-specific death (BCD) associated with any post-diagnostic statin use.

RESULTS

Of the 14,976 women included in analyses, 27% used a statin after diagnosis and the median follow up time was 4.51 years. Statin use (vs non-use) was associated with a statistically significant decreased risk of BCD (adjusted hazard ratio: 0.74; 0.63-0.86). The association was attenuated when considering a subgroup of 'new' statin users (HR: 0.91; 0.69-1.19), however other analyses revealed that the protective effect of statins was more pronounced in estrogen receptor positive patients (HR: 0.77; 0.63-0.94), postmenopausal women (HR: 0.74; 0.63-0.88), and in women with advanced stage disease (HR: 0.65; 0.49-0.84).

CONCLUSION

In this study, statin use was associated with a statistically significant decreased risk of breast cancer death, with subgroup analyses revealing a more protective effect in ER+ patients, postmenopausal women, and in women with advanced stage disease. Further research is warranted to determine if these associations are replicated in other clinical settings.

Effect of statins use on risk and prognosis of breast cancer: a meta-analysis

The findings regarding the association between statins use and breast cancer are inconsistent. Given the widely and long-term use of statins as first choice drug for dyslipidemia, we conducted this meta-analysis for better understanding the associations between statins use and the risk and prognosis of breast cancer. Articles regarding effect of statins use on risk, prognosis of breast cancer and published before January 2021 were searched in the following databases: Web of Science, PubMed, EMBASE, Medline and Google Scholar. Odds ratios (ORs)/relative risks (RRs) or hazard ratios (HRs) and their 95% confidence intervals (CIs) were computed to generate a pooled effect size and 95% CI. The meta-analysis showed no significant association between statins use and risk of breast cancer (OR/RR = 1.02; 95% CI, 0.97-1.08; I2 = 76.1%; P < 0.001). The meta-analysis showed that statins use was associated with lower breast cancer recurrence, all-cause mortality and disease-specific mortality (breast cancer recurrence: HR = 0.75; 95% CI, 0.67-0.84; I2 = 31.7%; P = 0.154; all-cause mortality: HR = 0.82; 95% CI, 0.77-0.89; I2 = 67.5%; P < 0.001; and disease-specific mortality: HR = 0.82; 95% CI, 0.72-0.93; I2 = 83.6%; P < 0.001). Overall, in this report we demonstrated that the use of statins can improve the prognosis of breast cancer patients including lower risks of breast cancer recurrence, all-cause and cancer-specific mortality, though statins therapy may not have an impact on reducing the risk of breast cancer.

Nanotherapeutics approaches to overcome P-glycoprotein-mediated multi-drug resistance in cancer

Multidrug resistance (MDR) in cancer chemotherapy is a growing concern for medical practitioners. P-glycoprotein (P-gp) overexpression is one of the major reasons for multidrug resistance in cancer chemotherapy. The P-gp overexpression in cancer cells depends on several factors like adenosine triphosphate (ATP) hydrolysis, hypoxia-inducible factor 1 alpha (HIF-1α), and drug physicochemical properties such as lipophilicity, molecular weight, and molecular size. Further multiple exposures of anticancer drugs to the P-gp efflux protein cause acquired P-gp overexpression. Unique structural and functional characteristics of nanotechnology-based drug delivery systems provide opportunities to circumvent P-gp mediated MDR. The primary mechanism behind the nanocarrier systems in P-gp inhibition includes: bypassing or inhibiting the P-gp efflux pump to combat MDR. In this review, we discuss the role of P-gp in MDR and highlight the recent progress in different nanocarriers to overcome P-gp mediated MDR in terms of their limitations and potentials.

Breast Cancer and Anaesthesia: Genetic Influence

Breast cancer is the leading cause of mortality in women. It is a heterogeneous disease with a high degree of inter-subject variability even in patients with the same type of tumor, with individualized medicine having acquired significant relevance in this field. The clinical and morphological heterogeneity of the different types of breast tumors has led to a diversity of staging and classification systems. Thus, these tumors show wide variability in genetic expression and prognostic biomarkers. Surgical treatment is essential in the management of these patients. However, the perioperative period has been found to significantly influence survival and cancer recurrence. There is growing interest in the pro-tumoral effect of different anaesthetic and analgesic agents used intraoperatively and their relationship with metastatic progression. There is cumulative evidence of the influence of anaesthetic techniques on the physiopathological mechanisms of survival and growth of the residual neoplastic cells released during surgery. Prospective randomized clinical trials are needed to obtain quality evidence on the relationship between cancer and anaesthesia. This document summarizes the evidence currently available about the effects of the anaesthetic agents and techniques used in primary cancer surgery and long-term oncologic outcomes, and the biomolecular mechanisms involved in their interaction.

CYP27A1 expression is associated with risk of late lethal estrogen receptor-positive breast cancer in postmenopausal patients

Background

27-Hydroxycholesterol (27HC) stimulates estrogen receptor-positive (ER+) breast cancer (BC) progression. Inhibiting the sterol 27-hydroxylase (CYP27A1) abrogates these growth-promoting effects of 27HC in mice. However, the significance of CYP27A1 expression on BC biology and prognosis is unclear.

Methods

Intratumoral CYP27A1 expression in invasive BC was measured by immunohistochemistry in two Swedish population-based cohorts (n = 645 and n = 813, respectively). Cox proportional hazards models were used to evaluate the association between CYP27A1 expression and prognosis.

Results

CYP27A1 was highly expressed in less than 1/3 of the tumors. High CYP27A1 expression was more frequent among high-grade tumors lacking hormone receptor expression and with larger tumor sizes. Over a median of 12.2 years follow-up in cohort 1, high CYP27A1 expression was associated with impaired survival, specifically after 5 years from diagnosis among all patients [overall survival (OS), HR_adjusted = 1.93, 95%CI = 1.26–2.97, P = 0.003; breast cancer-specific survival (BCSS), HR_adjusted = 2.33, 95%CI = 1.28–4.23, P = 0.006] and among patients ≥ 55 years presenting with ER+ tumors [OS, HR_adjusted = 1.99, 95%CI = 1.24–3.21, P = 0.004; BCSS, HR_adjusted = 2.78, 95%CI = 1.41–5.51, P = 0.003].

Among all patients in cohort 2 (median follow-up of 7.0 years), CYP27A1 expression was significantly associated with shorter OS and RFS in univariable analyses across the full follow-up period. However after adjusting for tumor characteristics and treatments, the association with survival after 5 years from diagnosis was non-significant among all patients [OS, HR_adjusted = 1.08, 95%CI = 0.05–2.35, P = 0.83 and RFS, HR_adjusted = 1.22, 95%CI = 0.68–2.18, P = 0.50] as well as among patients ≥ 55 years presenting with ER+ tumors [OS, HR_adjusted = 0.46 95% CI = 0.11–1.98, P = 0.30 and RFS, HR_adjusted = 0.97 95% CI = 0.44–2.10, P = 0.93].

Conclusion

CYP27A1 demonstrated great potentials as a biomarker of aggressive tumor biology and late lethal disease in postmenopausal patients with ER+ BC. Future studies should investigate if the benefits of prolonged endocrine therapy and cholesterol-lowering medication in BC are modified by CYP27A1 expression.

Association Between Statin Use and Prognosis of Breast Cancer: A Meta-Analysis of Cohort Studies

Background: Statin, a lipid-lowering drug, has been suggested to confer anticancer efficacy. However, previous studies evaluating the association between statin use and prognosis in breast cancer showed inconsistent results. A meta-analysis was performed to evaluate the association between statin use and clinical outcome in women with breast cancer.

Methods: Cohort studies comparing recurrence or disease-specific mortality in women with breast cancer with and without using of statins were identified by search of PubMed, Embase, and Cochrane's Library databases. A random-effect model, incorporating the inter-study heterogeneity, was used to combine the results. Subgroup analyses were performed to evaluate the influences of study characteristics on the outcomes

Results: Seventeen cohort studies with 168,700 women with breast cancer were included. Pooled results showed that statin use was significantly associated with a lower risk of breast cancer recurrence (adjusted hazard ratio [HR] = 0.72, p < 0.001) and breast cancer mortality (HR = 0.80, p < 0.001). Subgroup analysis showed that timing of statin use, statin type, study design, sample size, or quality score did not significantly affect the outcomes. However, statin use was associated with more remarkably reduced breast cancer recurrence in studies with mean follow-up duration ≤ 5 years (HR = 0.55, p < 0.001) than that in studies of >5 years (HR = 0.83, p = 0.01).

Conclusions: Statin use is associated with reduced recurrence and disease-specific mortality in women with breast cancer. These results should be validated in randomized controlled trials.

Perplexing Role of P-Glycoprotein in Tumor Microenvironment

Development of multidrug resistance (MDR) still remains a major obstacle to the long-term success of cancer therapy. P-glycoprotein (P-gp) is a well-identified membrane transporter with capability to efflux drug molecules out of the cancer cell leading to reduced efficiency of chemotherapy. Cancer cells upregulate P-gp expression as an adaptive response to evade chemotherapy mediated cell death. While several P-gp inhibitors have been discovered by in silico and pre-clinical studies, very few have successfully passed all phases of the clinical trials. Studies show that application of P-gp inhibitors in cancer therapy regimen following development of MDR achieved limited beneficial outcomes. While, the non-specific substrate binding to P-gp has made the drug-design a challenge, a bigger perplexing challenge comes from its role in tumor immunology. Expression of P-gp was noted immune cell phenotypes with apparently antagonistic functionality. Both pro-tumor MΦ2-macrophages and, anti-tumor NK-cell and Th17/CD4⁺T cell subsets have shown enhanced expression of P-gp. While drug based inhibition of P-gp in pro-tumor immune cell phenotypes could promote tumor elimination, however, it would not be a rational choice to exert inhibition of P-gp on anti-tumor immune cell phenotypes. This mutually exclusive paradigm of P-gp functionality requires a more comprehensive and detailed understanding of its role in tumor microenvironment with active interplay of cancer and immune cells in the tumor mileu. In this review, we focus on the current understanding of the role of P-gp in cancer cells and immune cells and finally attempt to highlight some caveats in the current understanding of its role in comprehensive tumor microenvironment along with challenges in the development of P-gp inhibitors toward anti-cancer therapy.