For patients with small, low-grade prostate cancer, delaying surgery -- even for years -- does not appear to increase the risk of the disease progressing to an incurable form.So finds a 10-year Johns Hopkins Medicine study. This discovery could prevent over-treatment, the authors say.
Published in the March 1, 2006 issue of the Journal of the National Cancer Institute, the study found the risk of noncurable prostate cancer was the same for men receiving immediate surgical treatment and those who waited (on average) two years before surgery. Risk of incurable cancer was defined as less than 75 percent chance of remaining disease-free 10 years after surgery.
Traditionally, urologists advise prostate cancer patients with small, lower-grade tumors to consider surgery with no delay. Expectant management with delayed surgical intervention (active surveillance) is a rarely used option because the opportunity for cure may be lost. Some researchers believe postponing surgery might shift the patient outside the window of curability. Others meanwhile have been gathering evidence to find out if, on the contrary, delayed treatment combined with a program of careful monitoring called Active Surveillance can decrease over-treatment with minimal risk.
Carter says Hopkins has been enrolling patients in a monitoring program since 1995 with great success, although some patients prefer to go ahead and pursue treatment for "peace of mind."
"Some patients who learn they have cancer are anxious to have treatment yesterday. We hope this study will illustrate that in many cases a safe alternative to immediate treatment is surveillance," Carter says. "Specifically, these would be men with small, low-grade tumors." Three-hundred and twenty men believed to have these kinds of tumors have been enrolled in Hopkins' active surveillance program since 1995.
Small, low-grade prostate cancer was defined as having a PSA density (PSA divided by prostate volume) below 0.15, no more than two biopsy cores involved with cancer, no biopsy core that showed more than 50 percent cancerous tissue and no high-grade cancer as measured by Gleason score.
Thirty-eight of the 320 patients delayed surgery for a median 26.5 months. Outcomes in these men were compared with a similar group of 150 men who had surgery after a median three months. Results showed that the risk of noncurable prostate cancer was the same for both groups. Factors associated with risk of non-curable prostate cancer included age at time of diagnosis, PSA level and PSA density.
The program used a followup protocol to decide when men should move ahead to active treatment: "Follow-up involves semiannual measurements of total and free PSA, a semiannual digital rectal examination, and an annual surveillance prostate biopsy examination. Curative surgery is triggered by the finding of adverse pathological features on an annual surveillance biopsy examination (i.e., a Gleason score of 7 or more with a Gleason pattern grade 4 or above, more than two cores that are positive for cancer, or more than 50% of any one core that is involved with cancer) or a patient's request for a change in management. In our program, total PSA changes have not triggered intervention."
Carter said his group is now studying blood and tissue samples from this population to better understand what puts patients at risk while they’re being monitored. He said they plan to look at biomarker changes, genetic factors and lifestyle choices.
"This study suggests that for carefully selected men with prostate cancer who are monitored, the window of cure does not close in the short term. For those men diagnosed with early-stage, low-grade prostate cancer, an alternative to immediate surgical treatment would be careful surveillance," says H. Ballentine Carter, M.D., a professor of urology at the Johns Hopkins School of Medicine and senior author of the study.
Men screened for prostate cancer with the prostate specific antigen (PSA) test are on average diagnosed with the cancer 10 years earlier than men not undergoing PSA screening. While early diagnosis may contribute to a decrease in prostate cancer mortality in some patients, it may lead to invasive treatments of a cancer that may never present a health risk to the patient.
SOURCES: Materials provided by Johns Hopkins and this free open access article:
Delayed versus immediate surgical intervention and prostate cancer outcome
J Natl Cancer Inst. 2006 Mar 1;98(5):355-7.
reported by J.Strax