Older men with low-risk prostate cancer received increasingly aggressive treatment over a 10-year period, whereas practices did not change for men most likely to benefit from curative therapy – those with a longer life expectancy, a study showed.
Use of curative therapy in men with a short life expectancy increased by 37% from 1998 to 2007, irrespective of tumor risk. During the same time period, the use of curative therapy decreased slightly in men with a long life expectancy.
The change in therapeutic approach for men with a short life expectancy drove an overall increase in the use of curative therapy, according to authors of a research letter published in the Feb. 27 issue of Archives of Internal Medicine.
“Given widespread concerns about the rate of increase in Medicare expenditures, it is notable that the most substantial increase in treatment in our sample was noted among the patients who were least likely to benefit,” Cary P. Gross, MD, of Yale University, and co-authors wrote in conclusion.
“Possible explanations include financial incentives, emergence of new therapies with perceived lower adverse effect profiles, and changes in patient preferences.
“The use of cancer therapies should be informed by clinical evidence and guided by patient preferences. Future work should explore how better to incorporate both cancer characteristics and patient life expectancy into decision making.”
The National Comprehensive Cancer Network has recommended active surveillance for men with low-risk prostate cancer and a life expectancy of less than 10 years. Curative therapy is recommended for intermediate-risk cancers and men with a life expectancy of 10 years or longer (J Natl Compr Cancer Netw 2010; 8: 145).
The Best Treatment for Low-Risk Prostate Cancer? Depends on the Patient
Men diagnosed with low-risk prostate cancer can opt for active surveillance rather than more invasive treatments without worrying about losing quality of life, suggests a study published in the Journal of the American Medical Association.
Researchers ran a computer simulation using data (culled from previous studies) on the success of various treatments. It found that in 65-year-old men, closely monitoring the patient to see if the disease progresses produced 11.1 quality years of life, compared to about 10.6 for internal radiation and 10.5 for external radiation. Men who have a radical prostatectomy can expect about 10.2 quality years of life, the model showed.
Of course, the results will depend on the assumptions used in the model. Randomized trials are the best way to compare different interventions (or non-interventions), but many men are uncomfortable being randomized to no treatment, says Ian Thompson, chairman of the urology department at the University of Texas Health Science Center at San Antonio. Thompson was the co-author of an editorial accompanying the research.
“The point is not necessarily that active surveillance was superior, but that with a wide range of assumptions, it wasn’t inferior,” he tells the Health Blog. “A man who faces a diagnosis of one of these smaller, slower-growing tumors should be offered this.” And decisions will vary depending on individual preferences – a man who really doesn’t want to experience the side effects of treatment such as impotence and incontinence will make one decision, while a man who dislikes uncertainty may make another, he says.
The number of therapeutic options for localized prostate cancer has expanded substantially in recent years, but little attention has been paid to the evolution of treatment and its relationship to the likelihood of benefit, the authors wrote in their introduction.
To examine the match between therapy and benefit, Gross and colleagues queried the NCI Surveillance, Epidemiology, and End Results (SEER) database linked to Medicare claims. They searched for men 67 to 84 who had newly diagnosed localized prostate cancer during 1998 to 2007.
The prostate-specific antigen (PSA) test used for cancer screening is anything but perfect, which is why the American Cancer Society advises men to carefully weigh the test’s risks and benefits.
Still, we do know that in general (though not always), a lower PSA score is associated with a lower risk of aggressive cancer. Researchers wanted to know what happens to men who are diagnosed with cancer but have relatively low PSA levels – 4.0 ng/mL or less. They found that 54% of those men had low-risk disease, as measured by that PSA reading, stage of the cancer, and Gleason score.
But more than 75% of them received aggressive treatment – a radical prostatectomy or radiation therapy. And men whose cancer was found via PSA screening were 49% more likely to receive that surgery and 39% more likely to have radiation than men whose cancer was detected in other ways – even though they were less likely to have high-grade disease.
In other words, screening with the PSA test seems to be associated with relatively aggressive treatment, even for men who are statistically at low risk of a life-threatening cancer. “These results underscore the fact that PSA level, the current biomarker, is not a sufficient basis for treatment decisions,” the authors write, adding that if the PSA threshold for a recommended biopsy was lowered further, there would be many more men receiving potentially unnecessary treatments.
The study is published in the Archives of Internal Medicine.
Yu-Hsuan Shao, PhD; Peter C. Albertsen, MD; Calpurnyia B. Roberts, PhD; Yong Lin, PhD; Amit R. Mehta, MD; Mark N. Stein, MD; Robert S. DiPaola, MD; Grace L. Lu-Yao, PhD
Arch Intern Med. 2010;170(14):1256-1261. doi:10.1001/archinternmed.2010.221
Investigators defined low-risk tumors as SEER grade 1 or 2 and stage T1 or T2a, and moderate-risk tumors as SEER grade 3 or 4 or stage T2b-T2c.
Using a Medicare 5% random sample of patients without cancer, they classified life expectancy as short (<5 years), intermediate (5 to 10 years), or long (≥10 years). Corresponding 10-year survival was 19.3%, 51.6%, and 76.1%, respectively.
Curative treatment was defined as radiation therapy or prostatectomy within nine months of prostate cancer diagnosis.
The study sample comprised 39,270 patients who had a median age of 74, and 43% of the patients had moderate-risk tumors.
Overall, 64.3% of the study population received curative therapy. Life expectancy had a significant association with the use of curative therapy: 39.1% of 3,557 patients with a short life expectancy; 62.7% of 23,721 patients with intermediate life expectancy; and 75.1% of 11,992 patients with a long life expectancy (P<0.001) received curative therapy.
Use of curative treatment overall increased from 61.2% of patients in 1998 to 67.6% in 2007 (P<0.001). Within the different categories of tumor risk, the proportion of men who received curative therapy varied by life expectancy.
Among men with intermediate-risk tumors and low life expectancy, use of curative treatment increased from 38% in 1998-1999 to 52.1% in 2006-2007. The rate declined slightly among men with a long life expectancy (80.7% to 80.0%, P=0.02 for life expectancy/time interaction).
Use of curative therapy trended downward for men with low-risk tumors and a long life expectancy but increased for men with a short or intermediate life expectancy.
A majority of men with newly diagnosed low-risk prostate cancer choose to undergo aggressive local intervention with either radical prostatectomy or radiation therapy, despite the high risk for complications and adverse effects and the availability of active surveillance as an alternative.
These conclusions, drawn from a study published in the July 26 issue of the Archives of Internal Medicine, once again illustrate the problems of overtreatment of prostate cancer, say experts contacted by Medscape Medical News.
In the study, Grace L. Lu-Yao, PhD, and colleagues from the Cancer Institute of New Jersey, in New Brunswick, analyzed data from the Surveillance, Epidemiology, and End Results database and found 123,934 men with prostate cancers that were newly diagnosed between 2004 and 2006.
The researchers found that 14% of the men had prostate-specific antigen levels lower than 4.0 ng/mL – the widely accepted threshold for recommending biopsy. Of this group, 54% had low-risk disease features, including disease confined within one half of 1 lobe of the prostate (stage T2a or less), Gleason score of 6 or less, and a PSA of 10 ng/mL or less.
Yet more than three fourths of all patients with PSAs lower than 4.0 ng/mL elected to undergo radical prostatectomy or radiation therapy. The team found that 44% of men with PSAs lower than 4.0 ng/mL underwent radical prostatectomy, and 33% had radiation.
“Our study found that aggressive local therapy was provided to most patients diagnosed as having prostate cancer,” Dr. Lu-Yao and colleagues write.
“These results underscore the fact that PSA level, the current biomarker, is not a sufficient basis for treatment decisions. Without the ability to distinguish indolent from aggressive cancers, lowering the biopsy threshold might increase the risk of overdiagnosis and overtreatment,” the investigators write.
Men with cancers detected by screening had a significantly lower risk of having high-grade disease compared with men with cancers detected by other means (odds ratio [OR] for screening, 0.67; 95% confidence interval [CI], 0.60 – 0.76), but the screen-detected cancers in men with PSAs lower than 4 were significantly more likely to be treated with either surgery (OR, 1.49; 95% CI, 1.38 – 1.62) or radiation (OR, 1.39; 95% CI, 1.30 – 1.49).
The same group of researchers has previously reported that conservative management of prostate cancer diagnosed in the age of PSA – from the 1990s on – had better outcomes than conservative management of disease diagnosed in the 2 previous decades, possibly because of “additional lead time, overdiagnosis related to PSA testing, grade migration, or advances in medical care” (JAMA. 2009;302(11):1202-1209).
“Men with localized prostate cancer may not receive curative therapy in accordance with clinical benefit,” the authors concluded. “During our study period, there was increasingly aggressive treatment of patients with a low likelihood of clinical benefit, without a commensurate increase in the treatment of patients with a high likelihood of clinical benefit.
“While not treating potentially fatal cancer can reflect poor-quality care, aggressive management of disease that is unlikely to progress puts patients at risk for morbidity and increases cost without medical benefits.”
Primary source: Archives of Internal Medicine
Source reference: Raldow AC, et al “The relationship between clinical benefit and receipt of curative therapy for prostate cancer” Arch Intern Med. 2012;72:62-363.