The Tables that Revolutionized Treatment Decision-Making: Now Bigger and Even Better
They call them the Partin tables, and they're everywhere: On several Internet websites, on laminated cards carried by doctors throughout the country, even on home computer programs.
Elegantly simple and meticulously accurate, the tables, developed by urologists Alan W. Partin, M.D., Ph.D., and Patrick C. Walsh, M.D., have quietly revolutionized the way doctors and patients are making decisions about treatment for prostate cancer.
Until these tables, there was no way to predict what urologists might find when they opened up a patients during radical prostatectomy; surgery can only cure prostate cancer if the disease has not spread too far beyond the confines of the prostate. Doctors could guess, but they couldn't be sure -- not until they examined the patient's pelvic lymph nodes (in a procedure called pelvic lymph node dissection), and sometimes not even then, if there were microscopic bits of cancer that had strayed from the prostate but weren't yet big enough to be seen.
Ingeniously correlating the three things that were known about a man's disease -- PSA level, Gleason score, and estimated clinical stage -- the tables produced something that had been desperately needed: An accurate, invaluable means of estimating the exact extent of a man's prostate cancer before surgery.
"We know that if you operated on everybody who came in with these three pieces of information, at best -- at very best -- about 45 to 50 percent would have organ-confined cancer," says Partin. Because surgery is best at curing cancers that are truly localized to the prostate, it would be better for everyone to know before the operation how extensive the cancer is; this might spare someone unnecessary surgery.
Similarly, radiation won't cure a man who has cancer in his pelvic lymph nodes, and the tables can help spare someone needless side effects of a treatment that won't be helpful.
The tables, first developed after Partin studied the course of prostate cancer in hundreds of Walsh's radical prostatectomy patients, were designed to help men and their doctors predict the definitive pathological stage (determined after surgery, when a pathologist examines the removed prostate for the presence of cancer) and best course of treatment.
Now the tables have been expanded to include data from three institutions -- The University of Michigan and Baylor College of Medicine, as well as Johns Hopkins -- and 4,135 men, operated on by nearly a dozen surgeons. (All three of these institutions have received SPORE grants, for Special Projects of Research Excellence, from the National Cancer Institute -- see related article.)
This latest study, says Partin, "sharpened the tables by having more power, because of the higher numbers. It also provided the capability of testing our hypothesis: We took two-thirds of the patients and recalculated the tables, and then with the third that we had randomly chosen, we tested to see how well we did. We were able to calculate the statistical accuracy of the tables and report that, as well." (Another advantage of tripling the size of patients in the study is that it filled in many of the blanks that had been left on the earlier tables because of a lack of information.)
The four tables predict a man's likelihood of having organ-confined disease; capsular penetration (cancer that has reached the prostate wall); cancer in the seminal vesicles; and cancer in the lymph nodes. For example, a man with a PSA of 3.7, clinical stage T1b, and Gleason score of 6 has a 61-percent chance of having organ-confined disease, with a 23-percent chance of having positive seminal vesicles.
"I think it's really helped the patients and their doctors when they're talking to each other about treatment," says Partin, "so the patient can just say, 'Just what are we looking at, with the information I have right now?'"
"Combination of PSA, Clinical Stage and Gleason Score to Predict Pathological Stage in Localized Prostate Cancer: A Multi-Institutional Update," Journal of the American Medical Association, April 1997. Alan W. Partin, Patrick C. Walsh, et al.