Cancer screening among patients with advanced cancer

Abstract

Context: Cancer screening has been integrated into routine primary care but does not benefit patients with limited life expectancy.

Objective: To evaluate the extent to which patients with advanced cancer continue to be screened for new cancers.

Design, setting, and participants: Utilization of cancer screening procedures (mammography, Papanicolaou test, prostate-specific antigen [PSA], and lower gastrointestinal [GI] endoscopy) was assessed in 87,736 fee-for-service Medicare enrollees aged 65 years or older diagnosed with advanced lung, colorectal, pancreatic, gastroesophageal, or breast cancer between 1998 and 2005, and reported to one of the Surveillance, Epidemiology, and End Results (SEER) tumor registries. Participants were followed up until death or December 31, 2007, whichever came first. A group of 87,307 Medicare enrollees without cancer were individually matched by age, sex, race, and SEER registry to patients with cancer and observed over the same period to evaluate screening rates in context. Demographic and clinical characteristics associated with screening were also investigated.

Main outcome measure: For each cancer screening test, utilization rates were defined as the percentage of patients who were screened following the diagnosis of an incurable cancer.

Results: Among women following advanced cancer diagnosis compared with controls, at least 1 screening mammogram was received by 8.9% (95% confidence interval [CI], 8.6%-9.1%) vs 22.0% (95% CI, 21.7%-22.5%); Papanicolaou test screening was received by 5.8% (95% CI, 5.6%-6.1%) vs 12.5% (95% CI, 12.2%-12.8%). Among men following advanced cancer diagnosis compared with controls, PSA test was received by 15.0% (95% CI, 14.7%-15.3%) vs 27.2% (95% CI, 26.8%-27.6%). For all patients following advanced diagnosis compared with controls, lower GI endoscopy was received by 1.7% (95% CI, 1.6%-1.8%) vs 4.7% (95% CI, 4.6%-4.9%). Screening was more frequent among patients with a recent history of screening (16.2% [95% CI, 15.4%-16.9%] of these patients had mammography, 14.7% [95% CI, 13.7%-15.6%] had a Papanicolaou test, 23.3% [95% CI, 22.6%-24.0%] had a PSA test, and 6.1% [95% CI, 5.2%-7.0%] had lower GI endoscopy).

Conclusion: A sizeable proportion of patients with advanced cancer continue to undergo cancer screening tests that do not have a meaningful likelihood of providing benefit.

Figure 1

Survival Probability for Patients With Advanced Cancer and Matched Cancer-Free Controls by Cancer Site For patients with advanced cancer, the median overall survival following case follow-up start date for lung cancer was 5 months; for colorectal cancer, 8 months; for pancreatic cancer, 4 months; for gastroesophageal cancer, 4 months; and for breast cancer, 16 months. The overall survival at 5 years for each cancer was 3%, 5%, 3%, 2%, and 16%, respectively. Each cancer-free control was matched to a case with the specific cancer diagnosis by age, sex, race/ethnicity, and Surveillance, Epidemiology, and End Results tumor registry. For the cancer-free controls, the median overall survival was not reached and the overall survival at 5 years was 82% for lung cancer, 80% for colorectal cancer, 81% for pancreatic cancer, 81% for gastroesophageal cancer, and 85% for breast cancer.

Figure 2

Cumulative Incidence Functions for Utilization of Screening Mammography, Papanicolaou test, PSA, and Lower GI Endoscopy Screenings Following Advanced Cancer Diagnosis by Cancer Site PSA, prostate-specific antigen; GI, gastrointestinal. P values were based on the Gray test (applicable to cumulative incidence curves). For each of the 4 screening tests, P<.001.