Dubai, United Arab Emirates (CNN) — Most men diagnosed with prostate cancer can delay or avoid aggressive treatments without affecting their chances of survival, according to new results from a long-term study in the United Kingdom.
Men participating in the study with their doctors to monitor low-to-moderate-risk prostate tumors (a strategy called active surveillance) reduced their risk of life-changing complications, such as urine leakage and erectile dysfunction, that could follow intensive treatment for the disease.
However, they were no more likely to die from cancer than those who underwent surgery to remove the prostate, or those treated with hormone blockers and radiation.
“The good news is that if you are diagnosed with prostate cancer, don’t panic, and take your time to make a decision,” said the study’s lead author, Dr. Faridy Hamdy, professor of surgery and urology at Oxford University.
Other experts not involved in the research agreed that the study was reassuring for men diagnosed with prostate cancer and their doctors.
The results do not apply to people with high-risk prostate cancer.
Hamdy noted that these aggressive cancers, which represent about 15% of all prostate cancer cases, still need prompt treatment.
But for others, the study adds to a growing body of evidence showing that monitoring for prostate cancer is the right thing to do more often.
The results of the study were presented Saturday at the European Association of Urology’s annual conference in Milan, Italy, and two studies on the data were published in the New England Journal of Medicine and NEJM Evidence.
A common disease that is often of low severity
Prostate cancer is the second most common type of cancer among men in the United States, after non-melanoma skin cancers.
Most prostate cancers grow very slowly, and it usually takes 10 years for a tumor trapped in the prostate to show serious symptoms.
The study, which lasted more than two decades, confirmed what many doctors and researchers knew, that the majority of prostate cancers detected through blood tests, which measure levels of a protein called prostate-specific antigen (PSA), will not harm men during their lifetime, nor do they need treatment.
Dr. Oliver Sartore, medical director of the Tulane Cancer Center, said the men should recognize that a lot has changed over time, and that doctors have improved their approach to diagnosis since the study began in 1999.
Sartore, who wrote an editorial about the study although he was not involved in it, noted that the men in the study had early-stage cancer and were often less likely to develop it.
Now, doctors have more tools, including MRI scans and genetic tests, that may help guide treatment and reduce overdiagnosis, he said.
Fearing that their findings might be irrelevant to people today, the scientists reassessed their patients using modern methods of grading prostate cancers.
By those criteria, that meant about a third of their patients had moderate or severe disease, which didn’t change the conclusions.
Does less treatment equal better care?
When the study began in 1999, routine PSA testing for men was the standard.
Many doctors encouraged yearly testing for their male patients when they were over 50.
This test is sensitive, but not accurate.
Cancer can raise PSA levels, but so can other things, such as infections, sexual activity, and even cycling.
Tests that show an elevated PSA level require further evaluation.
“Overall, it is believed that only about 30 percent of people with elevated PSA will actually develop cancer. Most of these do not need treatment,” Sartore said.
Over the years, studies and modeling have shown that using regular PSA tests to screen for prostate cancer may do more harm than good.
By some estimates, up to 84% of men with prostate cancer detected during routine screening do not benefit from having their cancers detected because their disease will not be fatal by the time they die from other causes.
Other studies have estimated that about 1 to 2 out of every 5 men with prostate cancer suffer from overtreatment.
The treatment did not affect the chances of survival
The trial followed more than 1,600 men diagnosed with prostate cancer in the UK between 1999 and 2009.
All of them had cancer that had not spread to other parts of their bodies.
Upon joining, the men were randomly assigned to three groups: the active control group, in which regular blood tests were used to monitor their PSA levels, the radiotherapy group, in which hormone blockers and radiation were used to shrink tumors, and the prostatectomy group.
The men who were placed in the active control group were able to join another group if their disease progressed.
Most of the men have been followed for about 15 years, and according to an analysis of the most recent data, the researchers were able to obtain follow-up information on 98% of the participants.
By 2020, 45 men, about 3% of the participants, had died of prostate cancer.
There were no significant differences in prostate cancer mortality among the three groups.
Hamdy believes that the study’s conclusions deserve consideration by the men and their doctors when evaluating treatment methods.