A large study that followed men across the US diagnosed with localized prostate cancer for over 10 years found they lived just as long whether they had surgery to remove the prostate or underwent observation. The researchers say their findings support observation over surgery for men with localized prostate cancer, especially if it is low-risk.
In their study, which was published online on 19 July in the New England Journal of Medicine, researchers from the Prostate Cancer Intervention versus Observation Trial (PIVOT) describe how, following diagnosis, between November 1994 through January 2002, they enrolled 731 men with localized prostate cancer, randomly assigned them to receive either radical prostatectomy or observation, and then followed their progress.
Radical prostatectomy is a surgical procedure that removes the entire prostate gland and some surrounding tissue.
The average age of the men at diagnosis was 67 years, and the method of diagnosis was through prostate specific antigen (PSA) blood tests and biopsies. About half the men went into the surgery group (364), and half into the observation group (367).
Although the observation group did not have the surgery, they were able to receive palliative care and chemotherapy if their cancer got worse.
During the median follow-up of 10 years, 47% (171 men) in the surgery group died, compared with 49.9% (183) in the observation group. In their analysis, the researchers calculated the hazard ratio for this as 0.88, with confidence interval (CI) ranging from 0.71 to 1.08 (P=0.22), and an absolute risk reduction of 2.9 percentage points.
In the surgery group, 5.8% of the men (21) died from prostate cancer or treatment, compared with 8.4% (31) in the observation group. For this, the calculated hazard ratio was 0.63, with 95% CI ranging from 0.36 to 1.09 (P=0.09) and an absolute risk reduction of 2.6 percentage points.
These figures did not change when they took into account other potential influencing factors such as age, race, medical conditions, and the type of tumor.
21.4% of the men in the surgery group had a complication within the first 30 days, the most common being infection. One of the men also died during this period.
The researchers classified the men, according to their PSA levels and Gleason scores, as having either low, intermediate, or high-risk prostate cancer.
The results showed that the men with low-risk cancer (PSA under 10, Gleason score under 7), were the least likely to benefit from radical prostatectomy.
The researchers say their findings support the idea that if the cancer is low risk, then observation is a better option for men with localized prostate cancer.
Although prostate cancer is a serious disease, and statistics show that it is the leading cause of cancer death among American men, most men diagnosed with the disease die with it rather than of it. In fact, more than 2.5 million men in the US who have been diagnosed with prostate cancer are alive today.
One of the problems with prostate cancer screening is that it can’t tell which cancers are aggressive and need treatment and which can be safely left alone and kept under observation. So, because of this, many men undergo surgery, which can often lead to unpleasant and sometimes long-lasting side effects such as impotence and incontinence.
However, the American Cancer Society says much has happened over the last few years to improve the treatment of prostate cancer patients.
“Watchful waiting”, until recently, was widely used. This meant waiting until the cancer caused symptoms before starting treatment.
But now, the more common approach is “active surveillance” or “expectant management”, which involves regular PSA tests, rectal exams and biopsies to more closely assess the level of threat, and if this rises, then the doctor may recomment radical treatment.
Men with average risk of prostate cancer should talk to their doctors about screening from the age of 50 onwards, says the American Cancer Society. For men at higher risk, including those with a father or brother who has prostate cancer, and African-American men, should have this conversation from the age of 45, they urge.
In a recent statement, the American Society of Clinical Oncology (ASCO) suggests for men with shorter life expectancy, the risks of harms from PSA tests and subsquent unnecessary treatment probably outweigh the benefits.
But for men with longer life expectancy, the risk versus benefit balance is less clear, and patients should have “well-informed” conversations with their doctors about the harms, potential benefits and the appropriate management options should prostate cancer be found, says the ASCO.
Written by Catharine Paddock PhD