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With an intense focus on prostate cancer, it is easy to overlook the reality of other causes of death or disability in making decisions about therapy. An example of this issue is the proliferation of molecular tests that have been validated to separate patients with “intermediate risk”, or “low risk” into “even lower” or “even higher” risk disease categories using a number of different gene expression profiles on the tumor or biopsy material. For example, Genomic Health offers the Oncotype Dx test that provides a “Genomic Prostate Score” that gives a patient who (based on clinical criteria such as PSA and number of biopsy cores positive) falls into a low or intermediate risk category another lab value (GPS) that can potentially be useful in making a decision about treatment. GenomeDx has a test that can evaluate high risk men after prostatectomy to more accurately predict metastatic disease at 5 years. There is a very balanced article on the challenges of using these tests (which are a potential step forward to be sure) in the real world of the clinic here.
However, in all of the excitement and marketing of these and other tests, a couple of key facts are often overlooked (and may be much more important in decision making). Prostate cancer is generally a slow disease anyway. Competing mortality looms large as patients get older. And most importantly, there are validated ways to put the “whole patient” into the picture before ordering these tests, whether they be a PSA, biopsy, or molecular analysis. The Charlson comorbidity index can be extremely useful in predicting survival and is barely ever mentioned in the molecular analysis literature/reports. It is a simple yes/no answer to whether a patient has any of these 12 conditions: diabetes, bleeding gastrointestinal ulcer, chronic lung disease, congestive heart failure, stroke, myocardial infarction, angina or chest pain, cirrhosis or liver disease, arthritis, inflammatory bowel disease, hypertension, and depression. In a lovely article published last year, the use of this analysis in relationship to prostate cancer mortality gave a vivid picture of prostate cancer mortality in the larger setting of 3533 men with prostate cancer. A snapshot of their data looks like this:
Very often, the comorbid conditions lead to death from another cause. In my opinion (and in my practice), we too often ignore our ability to quantify the risk of dying from “something else” when we focus so intensely on the PSA or other tests in counseling patients about what to do. It is also true that patient perception of test results can vary dramatically. One patient with a “GPS score” of 10 might be reassured, while another will perceive it as “not low enough” and opt for aggressive treatment rather than observation. To some extent this exposes the fallacy of “we need to separate the issue of treatment from that of diagnosis” thinking. Until the crystal ball becomes crystal clear, management of prostate cancer will remain challenging and requires the kind of wholistic thinking that is often better done by primary care physicians or public health professionals than by prostate cancer docs, or their patients.