Among men in the US, prostate cancer is one of the most common cancers. Though most forms of this disease grow slowly and do not cause any health problems, some treatments can cause serious side effects. Now, a new study suggests that treating older men who have early-stage prostate cancer and other underlying health problems with surgery or radiation could result in adverse outcomes.
The study was led by researchers at the University of California-Los Angeles (UCLA) and is published in the journal Cancer.
According to the Centers for Disease Control and Prevention (CDC), in 2010, 196,038 men in the US were diagnosed with prostate cancer and 28,560 men died from it.
The authors from this latest study - led by Timothy Daskivich, a UCLA Robert Wood Johnson fellow - note that an estimated 233,000 new cases of the disease will be diagnosed in the US in 2014, and nearly 30,000 men will die of it.
Additionally, though the reason for this is unclear, incidence rates are about 60% higher in African Americans.
The CDC highlight several different treatment options for men with prostate cancer, which include:
- Closely monitoring the prostate cancer with regular tests
- Surgery to remove the prostate
- Radiation therapy
- Hormone therapy to block cancer cells from getting hormones they need to grow
- Cryotherapy to freeze and kill cancer cells
- Biological therapy, which works with the body's immune system to help fight cancer
- High-intensity focused ultrasound, which directs high-energy sound waves at cancer cells to kill them.
However, the researchers say some of the more aggressive therapies, such as surgery or radiation therapy, do not help older early-stage prostate cancer patients live longer.
'Aggressive treatment of older, sicker men is ineffective'
For their investigation, the team followed 140,553 men 66 years of age or older with early-stage prostate cancer who were diagnosed between 1991-2007 as part of the Surveillance, Epidemiology and End Results (SEER) Medicare database.
Using a measure called the Charlson index, the researchers assessed the men and their health problems. This index is used to predict the 10-year mortality for a patient with a range of other health problems.
For example, the researchers explain that while a prostate cancer patient with diabetes may score a 1, a man with multiple or more severe health issues might score a 3 or above.
Overall, the results showed that men who also dealt with major medical conditions - including heart attack, chronic obstructive pulmonary disease (COPD) and diabetes - did not live any longer after receiving aggressive treatment, compared with those who received no treatment.
In detail, after following the men for 15 years after their diagnosis, the findings showed that the prostate cancer patients with Charlson scores below 3 who were treated with aggressive therapy had a lower risk of dying of prostate cancer, compared with men who did not receive treatment.
But the men with scores of 3 or higher did not experience a reduction in death risk from cancer. This is because they did not live long enough to benefit from it, explains Daskivich, who says they were more likely to die from another condition.
"In the past, we've relied on the basic argument that older and sicker men are much more likely to die of other things besides their prostate cancer that exposing them to aggressive treatment, and its debilitating side effects is a poor gamble.
Now we've shown that aggressive treatment of these men is ineffective. This information will help these men better maximize the quality of their remaining years."
Despite limitations, study may help clarify existing guidelines
Daskivich says their findings could help doctors who are advising prostate cancer patients on whether or not to go for treatment.
"The guidelines suggest the men with life expectancies of less than 10 years shouldn't be treated aggressively, but life expectancy is difficult to measure accurately," he adds.
In their study, the authors point to some limitations that could "affect generalizability of the results." The first is a lack of prostate-specific antigen (PSA) data, and inconsistent tumor grade definitions in the SEER database do not allow for precise tumor risk definitions.
Additionally, because the sample size decreases with increasing incidence of other health problems in the sickest men, the team says they were not able to best detect significant differences in cancer mortality between those treated aggressively and non-aggressively.
Still, the authors say their data "may help to clarify existing American Urological Association, National Comprehensive Cancer Network, and European Association of Urology guidelines regarding triage of treatment for men with early-stage prostate cancer in the setting of limited life expectancy."