User login
Previous research examining the association between cholesterol and breast cancer metabolism suggests that cholesterol-lowering medications such as statins may improve outcomes in breast cancer patients, Sixten Harborg, a medical student and PhD student at Aarhus University, Denmark, said in a presentation at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.
In addition, cardiovascular-related death is the second most common cause of death for breast cancer survivors, and given the survival rates in early breast cancer, there is a demand for cardioprotective initiatives and maintenance of cardioprotective drugs after diagnosis, he said in an interview.
What Is Known About Statins and Breast Cancer?
Statins are the most common drugs used to lower cholesterol and may deprive tumor cells of the cholesterol needed for cell membrane synthesis, Mr. Harborg said in his presentation.
Data from a randomized trial published in the Journal of Clinical Oncology in 2017 showed significantly improved disease-free survival, breast cancer–free interval, and distant recurrence–free interval in early stage breast cancer patients randomized to cholesterol-lowering medication vs. those who did not receive cholesterol-lowering medication.
The 2017 study prompted the creation of the MASTER study, a randomized, multicenter, double-blind, placebo-controlled trial comparing standard adjuvant therapy plus placebo to standard adjuvant therapy plus atorvastatin in patients with early breast cancer (NCT04601116), Mr. Harborg said. The MASTER trial is currently recruiting patients in Denmark.
How Was the Current Study Designed?
To provide preliminary analysis, Mr. Harborg and colleagues used an emulation trial design based on electronic health care data from 110,160 females with a diagnosis of stage I, II, or III breast cancer who were part of the Danish Breast Cancer Group, a national clinical registry in Denmark, between 2000 and 2020.
As defined in the European Journal of Epidemiology in 2017, target trial emulation involves application of randomized trial designs to observational data with the goal of improving the quality of observational epidemiology when a comparator trial is not yet available.
The researchers created a cohort of patients based on electronic health care data to simulate a target trial of the use of atorvastatin after breast cancer diagnosis. Patients were randomized to one of two treatment strategies: starting to use statins within 36 months of diagnosis, or not using statins. The primary outcome was death from breast cancer. The follow-up for the MASTER study starts with inclusion and ends with death, emigration from Denmark, end of clinical follow-up, or 10 years of follow-up (whichever comes first); the follow-up was the same in the current study.
The researchers calculated hazard ratios (HR) of breast cancer mortality in statin users vs. non–statin users and used a technique known as inverse-probability of censoring-weighting (IPCW) to estimate the effects of statin use based on prognostic factors.
What Did the Results Show?
The results favored statin use for improved survival in early breast cancer patients, Mr. Harborg said. Overall, the hazard ratio for breast cancer mortality was 0.96 in statin users compared with non–statin users, and was similar in both a Cox regression analysis (HR 0.81), and in a 10-year landmark analysis (HR 0.86).
The difference in mortality between statin and non–statin users was even stronger in patients who were receiving adjuvant chemotherapy (HR 0.94, 0.64, and 0.76 on the IPCW, Cox, and landmark analyses, respectively).
The results were in line with previous reports of statins’ effect on breast cancer survival, Mr. Harborg said in an interview.
“We believe the results encourage the continuous effort of the currently enrolling MASTER trial,” he said.
The results also suggest that deprescribing statins at the time of breast cancer diagnosis is not recommended, and that statin treatment can safely be prescribed to breast cancer patients with increased cardiovascular disease risk and/or dyslipidemia, Mr. Harborg said in the interview.
What Is the Takeaway Message for Clinical Practice?
“The clinical takeaway from our study is that statin use is associated with reduced risk of dying from breast cancer, but that it is not possible to determine the true effect of statins on breast cancer survival without a randomized, placebo-controlled trial,” Mr. Harborg told this publication. “Statins are inexpensive and well-tolerated drugs and may have a beneficial effect in terms of survival for breast cancer patients. However, with the current level of evidence [because the MASTER study is ongoing], we still cannot recommend that oncologists prescribe statins to prevent mortality from breast cancer,” he said.
What Are the Next Steps for Research?
The findings were limited by the study design, and real-world data are needed, Dr. Harborg said. Other limitations include the presence of residual bias, and the use of data based on prescription codes, but these were not considered to have an effect on the main conclusion of the study, Mr. Harborg said in the interview.
However, the results suggest that the addition of statins may improve outcomes for early breast cancer patients, especially when used with chemotherapy, and support the value of the ongoing MASTER study, he concluded.
Ultimately, the MASTER study will provide a more definitive answer to the question of whether statins should be added to the adjuvant treatment regimen of breast cancer to improve breast cancer outcomes, he said.
What Do Clinicians Think of the Study?
The current study is timely and highlights the need for phase 3 trials to examine the potential of statin use for breast cancer outcomes, Malinda T. West, MD, a medical oncologist and breast oncologist at the University of Wisconsin Carbone Cancer Center, Madison, said in an interview.
Questions for future research include whether statins can be used in combination with adjuvant abemaciclib if indicated, or how to best sequence these agents, said Dr. West, who was not involved in the study. Other questions raised by the current study include whether other cholesterol-lowering agents have a potential adjuvant benefit in reducing breast cancer recurrent and/or mortality, and whether the addition of statins would benefit subgroups such as HER2+ and triple negative breast cancer, she said.
“I was not surprised to see another study reporting benefit with statins and reduced risk of breast cancer recurrence and/or mortality, but I think the larger question is defining the subgroups who benefit the most, and identifying predictors for benefit or resistance,” Dr. West said in an interview.
Previous studies have shown that cholesterol elevation, specifically LDL levels, can be linked to increased tumor growth in breast cancer, so the lower mortality risk associated with lipid-lowering therapies in the current study was consistent, Peyton L. Reves, MD, a hematology/oncology fellow, also at the University of Wisconsin, said in an interview. In practice, data from the current study and previous research could be especially useful for patients with elevated LDL levels, said Dr. Reves, who was not involved in the study.
“These results could impact clinical practice in many ways, including leading to routine cholesterol monitoring in breast cancer patients on adjuvant therapy as well as the addition of lipid-lowering therapy with statins in these patients,” Dr. Reves said.
The findings showing particular benefit for patients on adjuvant chemotherapy highlight the need for more research on this specific population and the effect of statins on overall breast cancer mortality, to explore the extent to which the results of the current study were driven by the benefit seen in patients receiving adjuvant chemotherapy, Dr. Reves said.
The study was supported by Director Michael Hermann Nielsen’s Memorial Grant, Manufacturer Einar Willumsen’s Memorial Grant, Astrid Thaysen’s Grant for Medical Basic Research, Eva and Henry Fraenkel’s Memorial Fund, and the Novo Nordisk Foundation.
The researchers had no financial conflicts to disclose. Dr. West and Dr. Reves had no financial conflicts to disclose.
Previous research examining the association between cholesterol and breast cancer metabolism suggests that cholesterol-lowering medications such as statins may improve outcomes in breast cancer patients, Sixten Harborg, a medical student and PhD student at Aarhus University, Denmark, said in a presentation at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.
In addition, cardiovascular-related death is the second most common cause of death for breast cancer survivors, and given the survival rates in early breast cancer, there is a demand for cardioprotective initiatives and maintenance of cardioprotective drugs after diagnosis, he said in an interview.
What Is Known About Statins and Breast Cancer?
Statins are the most common drugs used to lower cholesterol and may deprive tumor cells of the cholesterol needed for cell membrane synthesis, Mr. Harborg said in his presentation.
Data from a randomized trial published in the Journal of Clinical Oncology in 2017 showed significantly improved disease-free survival, breast cancer–free interval, and distant recurrence–free interval in early stage breast cancer patients randomized to cholesterol-lowering medication vs. those who did not receive cholesterol-lowering medication.
The 2017 study prompted the creation of the MASTER study, a randomized, multicenter, double-blind, placebo-controlled trial comparing standard adjuvant therapy plus placebo to standard adjuvant therapy plus atorvastatin in patients with early breast cancer (NCT04601116), Mr. Harborg said. The MASTER trial is currently recruiting patients in Denmark.
How Was the Current Study Designed?
To provide preliminary analysis, Mr. Harborg and colleagues used an emulation trial design based on electronic health care data from 110,160 females with a diagnosis of stage I, II, or III breast cancer who were part of the Danish Breast Cancer Group, a national clinical registry in Denmark, between 2000 and 2020.
As defined in the European Journal of Epidemiology in 2017, target trial emulation involves application of randomized trial designs to observational data with the goal of improving the quality of observational epidemiology when a comparator trial is not yet available.
The researchers created a cohort of patients based on electronic health care data to simulate a target trial of the use of atorvastatin after breast cancer diagnosis. Patients were randomized to one of two treatment strategies: starting to use statins within 36 months of diagnosis, or not using statins. The primary outcome was death from breast cancer. The follow-up for the MASTER study starts with inclusion and ends with death, emigration from Denmark, end of clinical follow-up, or 10 years of follow-up (whichever comes first); the follow-up was the same in the current study.
The researchers calculated hazard ratios (HR) of breast cancer mortality in statin users vs. non–statin users and used a technique known as inverse-probability of censoring-weighting (IPCW) to estimate the effects of statin use based on prognostic factors.
What Did the Results Show?
The results favored statin use for improved survival in early breast cancer patients, Mr. Harborg said. Overall, the hazard ratio for breast cancer mortality was 0.96 in statin users compared with non–statin users, and was similar in both a Cox regression analysis (HR 0.81), and in a 10-year landmark analysis (HR 0.86).
The difference in mortality between statin and non–statin users was even stronger in patients who were receiving adjuvant chemotherapy (HR 0.94, 0.64, and 0.76 on the IPCW, Cox, and landmark analyses, respectively).
The results were in line with previous reports of statins’ effect on breast cancer survival, Mr. Harborg said in an interview.
“We believe the results encourage the continuous effort of the currently enrolling MASTER trial,” he said.
The results also suggest that deprescribing statins at the time of breast cancer diagnosis is not recommended, and that statin treatment can safely be prescribed to breast cancer patients with increased cardiovascular disease risk and/or dyslipidemia, Mr. Harborg said in the interview.
What Is the Takeaway Message for Clinical Practice?
“The clinical takeaway from our study is that statin use is associated with reduced risk of dying from breast cancer, but that it is not possible to determine the true effect of statins on breast cancer survival without a randomized, placebo-controlled trial,” Mr. Harborg told this publication. “Statins are inexpensive and well-tolerated drugs and may have a beneficial effect in terms of survival for breast cancer patients. However, with the current level of evidence [because the MASTER study is ongoing], we still cannot recommend that oncologists prescribe statins to prevent mortality from breast cancer,” he said.
What Are the Next Steps for Research?
The findings were limited by the study design, and real-world data are needed, Dr. Harborg said. Other limitations include the presence of residual bias, and the use of data based on prescription codes, but these were not considered to have an effect on the main conclusion of the study, Mr. Harborg said in the interview.
However, the results suggest that the addition of statins may improve outcomes for early breast cancer patients, especially when used with chemotherapy, and support the value of the ongoing MASTER study, he concluded.
Ultimately, the MASTER study will provide a more definitive answer to the question of whether statins should be added to the adjuvant treatment regimen of breast cancer to improve breast cancer outcomes, he said.
What Do Clinicians Think of the Study?
The current study is timely and highlights the need for phase 3 trials to examine the potential of statin use for breast cancer outcomes, Malinda T. West, MD, a medical oncologist and breast oncologist at the University of Wisconsin Carbone Cancer Center, Madison, said in an interview.
Questions for future research include whether statins can be used in combination with adjuvant abemaciclib if indicated, or how to best sequence these agents, said Dr. West, who was not involved in the study. Other questions raised by the current study include whether other cholesterol-lowering agents have a potential adjuvant benefit in reducing breast cancer recurrent and/or mortality, and whether the addition of statins would benefit subgroups such as HER2+ and triple negative breast cancer, she said.
“I was not surprised to see another study reporting benefit with statins and reduced risk of breast cancer recurrence and/or mortality, but I think the larger question is defining the subgroups who benefit the most, and identifying predictors for benefit or resistance,” Dr. West said in an interview.
Previous studies have shown that cholesterol elevation, specifically LDL levels, can be linked to increased tumor growth in breast cancer, so the lower mortality risk associated with lipid-lowering therapies in the current study was consistent, Peyton L. Reves, MD, a hematology/oncology fellow, also at the University of Wisconsin, said in an interview. In practice, data from the current study and previous research could be especially useful for patients with elevated LDL levels, said Dr. Reves, who was not involved in the study.
“These results could impact clinical practice in many ways, including leading to routine cholesterol monitoring in breast cancer patients on adjuvant therapy as well as the addition of lipid-lowering therapy with statins in these patients,” Dr. Reves said.
The findings showing particular benefit for patients on adjuvant chemotherapy highlight the need for more research on this specific population and the effect of statins on overall breast cancer mortality, to explore the extent to which the results of the current study were driven by the benefit seen in patients receiving adjuvant chemotherapy, Dr. Reves said.
The study was supported by Director Michael Hermann Nielsen’s Memorial Grant, Manufacturer Einar Willumsen’s Memorial Grant, Astrid Thaysen’s Grant for Medical Basic Research, Eva and Henry Fraenkel’s Memorial Fund, and the Novo Nordisk Foundation.
The researchers had no financial conflicts to disclose. Dr. West and Dr. Reves had no financial conflicts to disclose.
Previous research examining the association between cholesterol and breast cancer metabolism suggests that cholesterol-lowering medications such as statins may improve outcomes in breast cancer patients, Sixten Harborg, a medical student and PhD student at Aarhus University, Denmark, said in a presentation at the European Society for Medical Oncology (ESMO) Breast Cancer annual congress.
In addition, cardiovascular-related death is the second most common cause of death for breast cancer survivors, and given the survival rates in early breast cancer, there is a demand for cardioprotective initiatives and maintenance of cardioprotective drugs after diagnosis, he said in an interview.
What Is Known About Statins and Breast Cancer?
Statins are the most common drugs used to lower cholesterol and may deprive tumor cells of the cholesterol needed for cell membrane synthesis, Mr. Harborg said in his presentation.
Data from a randomized trial published in the Journal of Clinical Oncology in 2017 showed significantly improved disease-free survival, breast cancer–free interval, and distant recurrence–free interval in early stage breast cancer patients randomized to cholesterol-lowering medication vs. those who did not receive cholesterol-lowering medication.
The 2017 study prompted the creation of the MASTER study, a randomized, multicenter, double-blind, placebo-controlled trial comparing standard adjuvant therapy plus placebo to standard adjuvant therapy plus atorvastatin in patients with early breast cancer (NCT04601116), Mr. Harborg said. The MASTER trial is currently recruiting patients in Denmark.
How Was the Current Study Designed?
To provide preliminary analysis, Mr. Harborg and colleagues used an emulation trial design based on electronic health care data from 110,160 females with a diagnosis of stage I, II, or III breast cancer who were part of the Danish Breast Cancer Group, a national clinical registry in Denmark, between 2000 and 2020.
As defined in the European Journal of Epidemiology in 2017, target trial emulation involves application of randomized trial designs to observational data with the goal of improving the quality of observational epidemiology when a comparator trial is not yet available.
The researchers created a cohort of patients based on electronic health care data to simulate a target trial of the use of atorvastatin after breast cancer diagnosis. Patients were randomized to one of two treatment strategies: starting to use statins within 36 months of diagnosis, or not using statins. The primary outcome was death from breast cancer. The follow-up for the MASTER study starts with inclusion and ends with death, emigration from Denmark, end of clinical follow-up, or 10 years of follow-up (whichever comes first); the follow-up was the same in the current study.
The researchers calculated hazard ratios (HR) of breast cancer mortality in statin users vs. non–statin users and used a technique known as inverse-probability of censoring-weighting (IPCW) to estimate the effects of statin use based on prognostic factors.
What Did the Results Show?
The results favored statin use for improved survival in early breast cancer patients, Mr. Harborg said. Overall, the hazard ratio for breast cancer mortality was 0.96 in statin users compared with non–statin users, and was similar in both a Cox regression analysis (HR 0.81), and in a 10-year landmark analysis (HR 0.86).
The difference in mortality between statin and non–statin users was even stronger in patients who were receiving adjuvant chemotherapy (HR 0.94, 0.64, and 0.76 on the IPCW, Cox, and landmark analyses, respectively).
The results were in line with previous reports of statins’ effect on breast cancer survival, Mr. Harborg said in an interview.
“We believe the results encourage the continuous effort of the currently enrolling MASTER trial,” he said.
The results also suggest that deprescribing statins at the time of breast cancer diagnosis is not recommended, and that statin treatment can safely be prescribed to breast cancer patients with increased cardiovascular disease risk and/or dyslipidemia, Mr. Harborg said in the interview.
What Is the Takeaway Message for Clinical Practice?
“The clinical takeaway from our study is that statin use is associated with reduced risk of dying from breast cancer, but that it is not possible to determine the true effect of statins on breast cancer survival without a randomized, placebo-controlled trial,” Mr. Harborg told this publication. “Statins are inexpensive and well-tolerated drugs and may have a beneficial effect in terms of survival for breast cancer patients. However, with the current level of evidence [because the MASTER study is ongoing], we still cannot recommend that oncologists prescribe statins to prevent mortality from breast cancer,” he said.
What Are the Next Steps for Research?
The findings were limited by the study design, and real-world data are needed, Dr. Harborg said. Other limitations include the presence of residual bias, and the use of data based on prescription codes, but these were not considered to have an effect on the main conclusion of the study, Mr. Harborg said in the interview.
However, the results suggest that the addition of statins may improve outcomes for early breast cancer patients, especially when used with chemotherapy, and support the value of the ongoing MASTER study, he concluded.
Ultimately, the MASTER study will provide a more definitive answer to the question of whether statins should be added to the adjuvant treatment regimen of breast cancer to improve breast cancer outcomes, he said.
What Do Clinicians Think of the Study?
The current study is timely and highlights the need for phase 3 trials to examine the potential of statin use for breast cancer outcomes, Malinda T. West, MD, a medical oncologist and breast oncologist at the University of Wisconsin Carbone Cancer Center, Madison, said in an interview.
Questions for future research include whether statins can be used in combination with adjuvant abemaciclib if indicated, or how to best sequence these agents, said Dr. West, who was not involved in the study. Other questions raised by the current study include whether other cholesterol-lowering agents have a potential adjuvant benefit in reducing breast cancer recurrent and/or mortality, and whether the addition of statins would benefit subgroups such as HER2+ and triple negative breast cancer, she said.
“I was not surprised to see another study reporting benefit with statins and reduced risk of breast cancer recurrence and/or mortality, but I think the larger question is defining the subgroups who benefit the most, and identifying predictors for benefit or resistance,” Dr. West said in an interview.
Previous studies have shown that cholesterol elevation, specifically LDL levels, can be linked to increased tumor growth in breast cancer, so the lower mortality risk associated with lipid-lowering therapies in the current study was consistent, Peyton L. Reves, MD, a hematology/oncology fellow, also at the University of Wisconsin, said in an interview. In practice, data from the current study and previous research could be especially useful for patients with elevated LDL levels, said Dr. Reves, who was not involved in the study.
“These results could impact clinical practice in many ways, including leading to routine cholesterol monitoring in breast cancer patients on adjuvant therapy as well as the addition of lipid-lowering therapy with statins in these patients,” Dr. Reves said.
The findings showing particular benefit for patients on adjuvant chemotherapy highlight the need for more research on this specific population and the effect of statins on overall breast cancer mortality, to explore the extent to which the results of the current study were driven by the benefit seen in patients receiving adjuvant chemotherapy, Dr. Reves said.
The study was supported by Director Michael Hermann Nielsen’s Memorial Grant, Manufacturer Einar Willumsen’s Memorial Grant, Astrid Thaysen’s Grant for Medical Basic Research, Eva and Henry Fraenkel’s Memorial Fund, and the Novo Nordisk Foundation.
The researchers had no financial conflicts to disclose. Dr. West and Dr. Reves had no financial conflicts to disclose.
FROM ESMO BREAST CANCER 2024