WebMD reports a study (link here) whereby certain combinations of 13 common lab test results can predict high mortality in otherwise healthy septagenerians. Below is an excerpt from the article:
The finding comes from a detailed study of 1,189 remarkably healthy 70-something men and women, originally studied as examples of successful aging. Twelve years later, about half of these people were dead.... UCLA researcher Tara L. Gruenewald...analyzed results from 13 lab tests performed when these men and women first entered the study. These "biomarkers" covered risk factors for heart disease (such as blood pressure), tests of immune activation, tests for stress and steroidal hormones, and tests for metabolic factors [such as cholesterol]. Certain combinations of lab tests formed "trees" of death. For example, there were 28 deaths among 30 people in one particularly lethal "tree." This tree was a combination of high levels of adrenal hormones and high levels of C-reactive protein or CRP....[T]he findings, in combination with breakthroughs in understanding the genetic basis of common diseases, is leading to an era of individualized medicine.
This study is a good example of an approach to the use of biomarkers whereby a researcher starts with a study population and, in effect, works backwards. The process is analogous to analyzing tissue samples of metastatic prostatic tumor and determining which of its genes are upregulated and which are downregulated. These results can then be used to determine which biomarker pattern can be use to predict a tumor with the potential to metastasize. In this case, there was high mortality among septagenerians in a lab test "tree" with elevated CRP. CRP is the most sensitive of the acute phase proteins but, on a chronic basis, the test is a useful marker for existing arterial disease and future risk (link here).
With regard to individualized medicine, the key question in this case is what treatment a priori might have been offered to these subjects in the "lethal tree" to reduce their high morality rate. I called a cardiologist friend and he said that one obvious approach would have been to start them on a statins or, for those already being treated with a statin, to increase the dose.