Figure. Trends in the incidence of early-stage prostate tumors by age group. Rates are standardized by 5-year age groups and race/ethnicity to the 2009 population. Source: analysis of Surveillance, Epidemiology and End Results (SEER) 18 registry data. USPSTF indicates US Preventive Services Task Force.
Howard DH. Declines in prostate cancer incidence after changes in screening
recommendations. Arch Intern Med.. Published online July 23, 2012.
eTable. Trends in prostate cancer incidence by age and stage
Howard DH. Declines in Prostate Cancer Incidence After Changes in Screening Recommendations. Arch Intern Med. 2012;172(16):1267–1268. doi:10.1001/archinternmed.2012.2768
Author Affiliation: Department of Health Policy and Management, Emory University, Atlanta, Georgia.
On August 5, 2008, the US Preventive Services Task Force (USPSTF) recommended against screening men 75 years or older for prostate cancer.1 For men younger than 75 years, the USPSTF maintained its previous recommendation: “ . . . the evidence is insufficient to recommend for or against routine screening for prostate cancer. . . ”2(p915) (although this recommendation was changed to “do not screen” younger men in the 2011 guidelines). This study evaluates trends in prostate cancer incidence following the release of the 2008 USPSTF recommendation. If the revised recommendation led to a decline in prostate cancer screening rates, there should be a corresponding decline in the incidence of early-stage tumors among men 75 and older relative to trends in the incidence of late-stage tumors and early-stage tumors in younger men.
I measured trends in prostate cancer incidence rates by age group using the Surveillance, Epidemiology and End Results (SEER) 18 registry data, covering 28% of the US population. The SEER registries collect information on all newly diagnosed cancer cases in their respective catchment areas.
Prostate tumors were identified using International Classification of Diseases for Oncology version 3 code 619. I classified cases by stage at diagnosis using the derived American Joint Committee on Cancer summary stage variable: early (T1 or T2), late (T3 or T4), or unknown. I grouped patients into 3 age categories (30-64 years, 65-74 years, and 75 years and older). I calculated incidence rates per 100 000 persons, standardized within age categories by age (in 5-year age groups), race (white, black, American Indian, or other), and ethnicity (Hispanic or not Hispanic) to the 2009 population. I used an unpaired t test for proportions to assess the significance of differences in rates between years. The data were analyzed in Stata version 11 (StataCorp) statistical software.
The data included 254 184 prostate cancer cases. There were 198 417 early-stage cases, 34 695 late-stage cases, and 21 072 cases of unknown stage. There were 109 053 cases (all stages) among men aged 30 to 64 years, 91 868 cases among men aged 65 to 74 years, and 53 263 cases among men 75 years and older.
The Figure displays the age and race/ethnicity-adjusted incidence rates of early-stage tumors among men aged 65 to 74 years (the upper line) and 75 years and older (the lower line). The trend lines generally mirror each other, but there is a sudden decrease in the incidence of early-stage tumors among men 75 and older after the release of the revised USPSTF recommendation.
Between 2007 and 2009, the adjusted incidence rate for early-stage tumors among men 75 years and older decreased from 443 to 330 per 100 000 (−25.4%; P < .001). The absolute number of cases declined from 8137 to 6162. The incidence of late-stage tumors decreased from 83 to 71 (−14.3%; P < .001), and the incidence of tumors with unknown stage decreased from 124 to 103 (−16.8%; P < .001). The incidence of early-stage tumors among men aged 65 to 74 years decreased from 697 to 591 (−15.2%; P < .001). The incidence of early-stage tumors among men aged 30 to 64 years decreased from 105 to 93 (−11%; P < .001). Incidence trends for all age and stage groups are given in the eTable).
There was an immediate decline in the incidence of early-stage prostate cancer tumors among men 75 years and older after the USPSTF recommended against screening this group. The magnitude of the decline was larger than the secular decline in the incidence rate for other stage and age groups. The results are consistent with the hypothesis that the revision of the USPSTF recommendations led to a small to moderate decline in prostate cancer screening rates. Many men 75 years and older may continue to receive screening tests. Some of the decline in the incidence of late-stage tumors may be attributable to decreases in screening via digital rectal examinations.
Prasad et al3 report that there was no change in self-reported prostate-specific antigen (PSA) screening rates between the 2005 and 2010 National Health Interview Surveys. Self-reported PSA testing measures have poor sensitivity and specificity.4,5 Small physician surveys indicate that 20% to 30% of physicians do not always discuss PSA screening with patients prior to ordering tests.6,7 Physicians who discontinued prostate cancer screening for all men 75 years and older may not have discussed the decision with patients. A snapshot of self-reported PSA testing rates may lack sensitivity to detect small to moderate changes in screening patterns. Based on trends in prostate cancer incidence rates, the impact of the revised USPSTF recommendation on screening rates merits further investigation.
Correspondence: Dr Howard, Department of Health Policy and Management, Emory University, 1518 Clifton Rd NE, Atlanta, GA 30030 (email@example.com).
Published Online: July 23, 2012. doi:10.1001/archinternmed.2012.2768
Financial Disclosure: None reported.
Funding for Less Is More: Staff support for topics research funded by grants from the California Health Care Foundation and the Parsemus Foundation.
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