Scanning electron color-enhanced image depicts prostate cancer cells.
Photo courtesy Annie Cavanagh/Cell Image Library
With more than 240,000 new cases expected in the United States in 2012, prostate cancer is among the nation’s most common tumor types.1 And yet despite its prevalence, treatment decisions remain fraught with controversy. From solo oncology practices to technology-filled cancer centers, physicians and their patients continue to grapple with wrenching and fateful decisions over the disease’s management.
A 2009 National Cancer Institute (NCI) study2 showing that annual screening for prostate cancer led to more diagnoses but no fewer deaths starkly illustrates the conflicts. Some patients benefit little from the surgery, radiation, and other treatments prompted by their diagnoses, the NCI noted, while suffering debilitating adverse events such as incontinence and impotence.
Faced with these high-stakes choices, a growing number of physicians are turning to predictive tools called nomograms to help them gauge more precisely how a patient’s cancer is likely to progress and to better assess the chance of a cure through a given treatment.
James Mohler, MD
Derived from institutional databases that include clinical and outcomes data for anywhere from hundreds to thousands of patients, these formulas consider multiple factors such as prostate-specific antigen (PSA) levels and Gleason scores—weighted to reflect their relative contribution to a particular outcome—to calculate a patient’s pathologic stage, chance of recurrence, and likelihood of a cure, among other results.
“We use nomograms as an important part of the education of every patient,” said James Mohler, MD, associate director and senior vice president for Translational Research and chairman of the Department of Urology at Roswell Park Cancer Institute in Buffalo, New York. “They really help men assess their pathologic stage and cure rate.”
Now widely available on the Internet, nomograms enable patients weighing treatment options to plug in their own clinical data and receive the probability of an outcome, such as the likelihood that their cancer is organ-confined.
The widening use of nomograms, however, has drawn the scrutiny of some skeptics, who question their predictive power and urge patients and physicians to closely examine the data from which they are derived. Those who embrace them insist that their ability to harness the predictive power of data represents a huge advance over anecdotal evidence.
Alan W. Partin, MD, PhD
Patients’ Questions Led to Development
Alan W. Partin, MD, PhD, director of the Brady Urological Institute at Johns Hopkins Medicine in Baltimore, Maryland, and a pioneer in the field, recounted his patients’ hunger for more precise assessments of their cancer and their frustration over the lack of it.
“When we would talk about risk with patients, they would ask us, ‘How good is good? Are we talking about 10% good or 90% good?’ “ recalled Partin, who 2 decades ago began to examine information from a large group of men “with similar blood tests, exams, and pathology reports” who had undergone radical prostatectomies at Johns Hopkins “to see how the cancer had spread.”
In 1993, he and Patrick C. Walsh, MD, then the institute’s urologist-in-chief, developed probability tables known as Partin tables by correlating 3 key pieces of information—PSA level, Gleason score, and estimated clinical stage—with patients’ actual pathologic stage. The tables perform what the institute calls a “virtual surgery” by allowing physicians to predict what would be found if the prostate were removed surgically and examined by a pathologist.