The use of androgen suppression therapy (AST) in prostate cancer for low-risk cases declined following a decrease in physician reimbursement, according to a study published online TK in The Journal of the National Cancer Institute. However, the indicated use of AST for metastatic disease in the palliative setting did not decline in the same period.
The use of AST in prostate cancer increased more than threefold between 1991 and 1999 both for patients with metastatic cancer and those with low-risk disease, but AST treatment in the latter group has not been shown to improve survival. The Medicare Modernization Act, passed in 2003, reduced reimbursements for AST by 64% between 2004 and 2005, but the effect on prescribed treatments is unknown.
To determine whether this bill reduced usage of AST in both patients with metastatic disease and those with low-risk disease, Sean P. Elliott, M.D., of the University of Minnesota, and colleagues, conducted an observational study of a cohort of men in the U.S. with prostate cancer. The cohort, which was identified by the Surveillance, Epidemiology and End Results (SEER) database, included 72,818 men, 64,788 of whom had low-risk disease, and 8,030 with metastatic disease.
The researchers found that for men with metastatic disease, there was no statistically significant change in AST usage between 2004 and 2005. For men with low-risk prostate cancer, for whom AST is not a generally accepted indication, usage of AST fell by 40 percent.
The authors controlled for various factors that could account for these findings, apart from reimbursement, including a trend toward using longer-acting agents, intermittent AST use, or growing awareness of side effects associated with AST. However, they conclude that the decline "likely represents a real effect of reimbursement change and not physician awareness of clinical evidence." Furthermore, they do not suggest that financial incentives led to increased AST use in the 1990s. "Our analysis only allows us to conclude that the reduction in reimbursement is associated with a decline in use in 2004-2005," they write.
In an accompanying editorial, Nancy L. Keating, M.D., of Brigham and Women's Hospital and Harvard Medical School, writes that although the effect of the Medicare Modernization Act on non-prostate cancers needs further study, this study's findings "provide reassurance that, at least for prostate cancer patients, the Medicare Modernization Act is not promoting over-use or negatively influencing access to recommended care of GnRH agonist therapy, and it may actually be leading to more appropriate care."
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