The Association between Treatment for Metabolic Disorders and Breast Cancer Characteristics

The effect of non-oncology drugs on clinical and genomic risk in early luminal breast cancer

BACKGROUND

An effect of non-oncology medications on cancer outcome has been proposed. In this study, we aimed to systematically examine the impact of commonly prescribed non-oncology drugs on clinical risk and on the genomic risk [based on the Oncotype DX recurrence score (RS)] in early breast cancer (BC).

EXPERIMENTAL DESIGN

We collected data on clinical risk (stage and grade), genomic risk (Oncotype DX RS), and on non-oncology medications administered to 1423 patients with estrogen receptor-positive human epidermal growth factor receptor 2-negative BC during the month of their surgery. The influence of various medications on clinical and genomic risks was evaluated by statistical analysis.

RESULTS

Out of the multiple drugs we examined, levothyroxine was significantly associated with a high Oncotype DX RS (mean 24.78; P < 0.0001) and metformin with a low Oncotype DX RS (mean 14.87; P < 0.01) compared with patients not receiving other non-oncology drugs (mean 18.7). By contrast, there were no differences in the clinical risk between patients receiving metformin, levothyroxine, or no other non-oncology drugs. Notably, there was no association between the consumption of levothyroxine and metformin and proliferation marker (Ki67) levels, but both drugs were significantly associated with progesterone-related features, suggesting that they influence genomic risk through estrogen-dependent signaling.

CONCLUSIONS

The results of this study indicate a significant impact of metformin and levothyroxine on clinical decisions in luminal BC, with potential impact on the clinical course of these patients.

Atorvastatin facilitates chemotherapy effects in metastatic triple-negative breast cancer

BACKGROUND

Metastatic triple-negative breast cancer (mTNBC) is treated mainly with chemotherapy. However, resistance frequently occurs as tumours enter dormancy. Statins have been suggested as effective against cancer but as they prolong and promote dormancy, it is an open question of whether the concomitant use would interfere with chemotherapy in primary and mTNBC. We examined this question in animal models and clinical correlations.

METHODS

We used a xenograft model of spontaneous metastasis to the liver from an ectopic tumour employing a mTNBC cell line. Atorvastatin was provided to sensitise metastatic cells, followed by chemotherapy. The effects of statin usage on outcomes in women with metastatic breast cancer was assessed respectively by querying a database of those diagnosed from 1999 to 2019.

RESULTS

Atorvastatin had limited influence on tumour growth or chemotherapy effects in ectopic primary tumours. Interestingly, atorvastatin was additive with doxorubicin (but not paclitaxel) when targeting liver metastases. E-cadherin-expressing, dormant, breast cancer cells were resistant to the use of either statins or chemotherapy as compared to wild-type cells; however, the combination of both did lead to increased cell death. Although prospective randomised studies are needed for validation, our retrospective clinical analysis suggested that patients on statin treatment could experience prolonged dormancy and overall survival; still once the tumour recurred progression was not affected by statin use.

CONCLUSION

Atorvastatin could be used during adjuvant chemotherapy and also in conjunction with metastatic chemotherapy to reduce mTNBC cancer progression. These preclinical data establish a rationale for the development of randomised studies.

Diabetes and Metformin Association with Recurrence Score in a Large Oncotype Database of Breast Cancer Patients

<b><i>Background:</i></b> The Oncotype DX® (ODX) is a genomic assay that provides clinicians with a prediction of benefit of chemotherapy in node-negative, tamoxifen-treated breast cancer. However, the relationship between ODX recurrence score (RS) and diabetes, a common comorbidity in breast cancer patients, has been inadequately described in the literature. Specifically, the association of diabetes treatment with metformin and RS is inconclusive, with different studies reporting conflicting results. Because diabetes has been associated with higher RS, it has been suggested that management of diabetes with metformin in breast cancer patients may be associated with a lower RS. <b><i>Objectives:</i></b> We studied a large cohort of early-stage, hormone-positive breast cancer patients to determine if there is an association between RS and metformin treatment. <b><i>Methods:</i></b> In this study, we retrospectively examined the medical records of 514 early-stage, hormone-positive breast cancer patients who had oncotype testing performed between 2007 and 2017. Number (%) or median were used to describe the patients’ characteristics between groups and were compared by the Kruskal-Wallis test at a significance level of 5%. <b><i>Results:</i></b> Of this cohort, 67 (13%) had a diabetes diagnosis at the time of breast cancer diagnosis, including both diabetes mellitus and pre-diabetes. The median RS for non-diabetic patients was 16 and the median RS for diabetic patients was 15. This difference was not significant, nor was there a statistical difference in RS between diabetic patients taking metformin (median RS = 15) and diabetic patients not taking metformin (median RS = 15). These results held true even when controlling for BMI. <b><i>Conclusions:</i></b> We conclude that neither diabetes diagnosis nor metformin use is associated with a difference in oncotype RS in this population of diabetic patients.

Type 2 Diabetes, but Not Insulin (Analog) Treatment, Is Associated With More Advanced Stages of Breast Cancer: A National Linkage of Cancer and Pharmacy Registries

OBJECTIVE

To investigate whether women with type 2 diabetes (T2D) develop a more advanced stage of breast cancer and whether treatment with insulin (analogs) is associated with specific breast cancer characteristics.

RESEARCH DESIGN AND METHODS

For this nested case-control study, women with breast cancer diagnosed in 2002-2014 were selected from the linked Netherlands Cancer Registry-PHARMO Database Network (N = 33,377). T2D was defined as receiving two or more dispensings of noninsulin blood glucose-lowering drugs prior to breast cancer diagnosis. Women with T2D were matched to women without diabetes. Among women with T2D, insulin users and nonusers were compared. Multivariable ordinal logistic regression was used to investigate the association between T2D/insulin and breast cancer characteristics, including TNM classification (tumor size, lymph node status, metastasis), morphology, grade, estrogen receptor and progesterone receptor (PR), human epidermal growth factor receptor 2, and molecular subtype.

RESULTS

Women with T2D (n = 1,567) were more often diagnosed with a more advanced tumor stage (odds ratio 1.28 [95% CI 13-1.44]) and a higher grade (1.22 [1.08-1.39]) though less often with a PR-negative breast tumor (0.77 [0.67-0.89]) than women without diabetes (n = 6,267). No associations were found for the other breast cancer characteristics. Women with T2D using insulin (n = 388) were not diagnosed with different breast cancer characteristics compared with women with T2D not using insulin (n = 1,179).

CONCLUSIONS

Our study suggests that women with T2D are at increased risk to be diagnosed with a more aggressive type of breast cancer than women without diabetes. No evidence was found that the use of insulin (analogs) is associated with developing more advanced breast cancer tumors.

p53 as a Regulator of Lipid Metabolism in Cancer

Enhanced proliferation and survival are common features of cancer cells. Cancer cells are metabolically reprogrammed which aids in their survival in nutrient-poor environments. Indeed, changes in metabolism of glucose and glutamine are essential for tumor progression. Thus, metabolic reprogramming is now well accepted as a hallmark of cancer. Recent findings suggest that reprogramming of lipid metabolism also occurs in cancer cells, since lipids are used for biosynthesis of membranes, post-translational modifications, second messengers for signal transduction, and as a source of energy during nutrient deprivation. The tumor suppressor p53 is a transcription factor that controls the expression of proteins involved in cell cycle arrest, DNA repair, apoptosis, and senescence. p53 also regulates cellular metabolism, which appears to play a key role in its tumor suppressive activities. In this review article, we summarize non-canonical functions of wild-type and mutant p53 on lipid metabolism and discuss their association with cancer progression.