Lack of Discontinuation of Statin Therapy After Diagnosis of End-Stage Cancer

Abstract

Aim of the study: To determine the rate and indication for statin use in a cohort of individuals with end-stage cancer; and quantify the statin discontinuation rate in a subgroup of these patients prescribed statins for primary prevention of cardiovascular disease.

Methods: Study subjects (N=484) were identified from FOCUS, a 4-year multicenter study that enrolled patients with stage III or IV breast, colorectal, lung, and prostate cancer. Subjects with hyperlipidemia (HLD) were identified at the time of study enrollment and clinical indication was determined. For a subset of patients, statin usage, discontinuation rate, and reason for discontinuation were recorded.

Results: One hundred and eight (92%) patients with HLD were taking a statin, of which 65 (60%) were prescribed statin therapy for primary prevention. Prescribing and discontinuation data were available for 48 statin users, of which 31 (65%) were prescribed statins for primary prevention. At study termination, 22 (71%) of the 31 primary prevention subjects died, 3 (10%) were lost to follow-up, and 6 (19%) were alive. Of the 22 deceased patients, 21 (95%) were on statin therapy within 1 year of death and 19 (86%) remained on statin therapy within 6 months of death (discontinuation rate 13.6%).

Conclusion: The diagnosis of end-stage cancer rarely led to the clinically indicated discontinuation of statin therapy when prescribed for primary prevention.

Introduction

Methods

Figure 1. Statin Use by Indication

Results

Discussion

Figure 2. Statin Continuation Rate

Statin therapy is recommended as part of the management for the primary prevention of cardiovascular disease (CVD).1 For this indication, 3 to 6 years of therapy is required to attain clinical benefit.¹ Patients with life-limiting conditions, such as end-stage cancer, are at greater risk for adverse reactions from these agents.² Thus, the discontinuation of therapy in appropriate situations where risks outweigh health gains would benefit individuals and the healthcare system by reducing expenditures. A Department of Veterans Affairs study reported that physicians prescribed statins at similar rates to veterans with certain palliative care index diagnoses during the last 6 months of life, compared with a control population without life-limiting diagnoses.³ To extend this literature, the aims of our study were to: (1) determine the rate and indication for statin use in a cohort of individuals with end-stage cancer; and (2) quantify the statin discontinuation rate and reason for discontinuation in a subgroup of patients prescribed statins for primary prevention of CVD. Study subjects (N=484) were identified from FOCUS, a 4-year multicenter study that enrolled patients with stage III or IV breast cancer (N=157), colorectal cancer (N=123), lung cancer (N=141), and prostate cancer (N=63).⁴ In FOCUS, advanced cancer refers to patients expected to live 6 months but who have a limited 5-year survival. Subjects with hyperlipidemia (HLD) were identified at the time of study enrollment. Once HLD was recognized, study records were reviewed to confirm each HLD diagnosis and determine the clinical indication (primary or secondary prevention) for statin use. For a subset of patients, statin usage (within 6 months to 1 year of death), discontinuation rate, and reason for discontinuation were recorded. Patients were determined to be continued on therapy if the statin was not removed from the patient summary list in the medical record or from the active medication list in the most recent primary care or oncology note. Medical approval was obtained from the Institutional Review Board. Of the 484 FOCUS subjects, 117 (24%) had a diagnosis of HLD at enrollment. One hundred and eight (92%) patients with HLD were taking a statin, of which 65 (60%) were prescribed statin therapy for primary prevention (Figure 1). Prescribing and discontinuation data were available for 48 statin users, of which 31 (65%) were prescribed statins for primary prevention (Figure 1). At study termination, 22 (71%) of the 31 primary prevention subjects died, 3 (10%) were lost to follow-up, and 6 (19%) were alive. Of the 22 deceased patients, 21 (95%) were on statin therapy within 1 year of death and 19 (86%) remained on statin therapy within 6 months of death (discontinuation rate 13.6%, Figure 2). Reasons for discontinuation were progression of cancer (n=2) and proven liver metastasis (n=1). The diagnosis of end-stage cancer rarely led to the clinically indicated discontinuation of statin therapy when prescribed for primary prevention. Reasons may include physician’s lack of awareness of duration of therapy necessary to achieve a clinical benefit, and/or patients’ unwillingness to discontinue a preventive medication despite poor prognosis. Discontinuation of chronic medications when harm exceeds clinical benefit may lower adverse reactions, reduce medication regimen complexity, and result in significant savings to patients and the healthcare system. Physician and patient education regarding benefits and potential harms of chronic medication use, as well as the advantages of stopping medications after a diagnosis of life-limiting conditions, is warranted.

About the Authors

Affiliations:

Jeffrey J. Wargo, MD, is a hospitalist and clinical lecturer in Internal Medicine; Laurel L. Northouse, PhD, is the Mary Lou Willard French Professor of Nursing; Ann M. Schafenacker, RN, is in the School of Nursing; and A. Mark Fendrick, MD, is a professor of Medicine and professor of Health Management and Policy at the University of Michigan in Ann Arbor.

Disclosures:

The authors report no financial interest with any entity that would pose a conflict of interest with the subject matter of this article.

Address correspondence to:

Jeffrey J. Wargo, MD, University of Michigan Health System, 1500 E. Medical Center Dr, Ann Arbor, MI 48109. E-mail: wargoj@med.umich.edu.

References

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