The Effect of Age and Chronic Illness on Life Expectancy after a Diagnosis of Colorectal Cancer: Implications for Screening

7 November 2006 | Volume 145 Issue 9 | Pages 646-653

Background: Older adults with shorter life expectancies may receive less benefit from colorectal cancer screening than younger, healthier patients.

Objective: To determine the degree to which life expectancy after diagnosis of an early-stage cancer varies according to age or coexisting chronic illness.

Design: Retrospective cohort study.

Setting: Population-based cancer registry with linked administrative claims data.

Patients: Patients 67 years of age or older who received a diagnosis of colorectal cancer from 1993 through 1999.

Measurements: Chronic conditions were identified by searching Medicare claims. Using a life-table approach, the authors quantified the degree to which life expectancy associated with each cancer stage at diagnosis varied with patient age, sex, and burden of chronic conditions.

Results: The final study sample consisted of 35 755 patients. After accounting for cancer stage at diagnosis, the authors found that life expectancy was strongly related to both age and the burden of chronic illness. Among men who received a diagnosis of stage I cancer at 67 years of age, life expectancy decreased from 19.1 years (95% CI, 17.8 to 20.5 years) for patients with no chronic conditions to 12.4 years (CI, 11.4 to 13.5 years) for those with 1 or 2 conditions and 7.6 years (CI, 6.1 to 9.4 years) for those with 3 or more conditions. A similar trend was noted among female counterparts, with life expectancy decreasing from approximately 23 years to 16 years and 7 years for the 3 chronic condition groups, respectively. For men and women 81 years of age with no chronic illnesses, life expectancy after stage I cancer diagnosis was 10.3 years (CI, 9.2 to 11.9 years) and 13.8 years (CI, 12.3 to 15.3 years), respectively.

Limitations: Administrative claims may not identify all chronic conditions. Life expectancy estimates at the population level are averages and, therefore, may not accurately predict the life expectancy of individual patients.

Conclusions: Coexisting chronic illness is associated with a substantial reduction in life expectancy after diagnosis of early-stage colorectal cancer. Physicians should consider this when deciding whether to screen older persons.

Editors' Notes Context When to stop screening for cancer should depend on a person's life expectancy and, thus, on age and health status. Contribution The authors used the Surveillance, Epidemiology, and End Results (SEER) data set and Medicare files to calculate life expectancy of patients with colorectal cancer at a given age and with specific chronic diseases. Patients between 76 and 81 years of age who had stage I colorectal cancer and 3 or more chronic diseases had life expectancies of 5 years or less. Cautions The authors probably underestimated chronic disease prevalence. Implications A heavy burden of chronic diseases is one reason to stop screening older persons for colorectal cancer. —The Editors

 

Author and Article Information

From the Robert Wood Johnson Clinical Scholars Program and Yale University School of Medicine, New Haven, Connecticut.

Disclaimer: Although this study used the linked SEER–Medicare database, the interpretation and reporting of these data are solely the authors' responsibility.

Acknowledgments: The authors acknowledge the efforts of the Applied Research Program, National Cancer Institute; the Office of Research, Development and Information, Centers for Medicare & Medicaid Services; Information Management Services, Inc.; and the SEER Program tumor registries in the creation of the SEER–Medicare database.

Grant Support: Dr. Gross was supported by a Beeson Career Development Award (1 K08 AG24842) and by the Claude D. Pepper Older Americans Independence Center at Yale (P30AG21342).

Potential Financial Conflicts of Interest: None disclosed.

Requests for Single Reprints: Cary P. Gross, MD, Primary Care Center, Yale University School of Medicine, 333 Cedar Street, PO Box 208025, New Haven, CT 06520; e-mail, cary.gross{at}yale.edu.

Current Author Addresses: Drs. Gross and Bhasin: Primary Care Center, Yale University School of Medicine, 333 Cedar Street, PO Box 208025, New Haven, CT 06520.

Drs. McAvay and Tinetti: Yale University Program on Aging, 333 Cedar Street, New Haven, CT 06520.

Dr. Krumholz: Yale University School of Medicine, Sterling Hall of Medicine (SHM), Room IE-61, 333 Cedar Street, PO Box 208088, New Haven, CT 06520-8088.

Dr. Paltiel: Laboratory of Epidemiology and Public Health, Yale University School of Medicine, Room 3050, 333 Cedar Street, New Haven, CT 06520.

Author Contributions: Conception and design: C.P. Gross, G.J. McAvay, M.E. Tinetti.

Analysis and interpretation of the data: C.P. Gross, G.J. McAvay, H.M. Krumholz, A.D. Paltiel, D. Bhasin.

Drafting of the article: C.P. Gross, G.J. McAvay, D. Bhasin.

Critical revision of the article for important intellectual content: G.J. McAvay, H.M. Krumholz, A.D. Paltiel, M.E. Tinetti.

Final approval of the article: C.P. Gross, H.M. Krumholz, A.D. Paltiel, M.E. Tinetti.

Statistical expertise: C.P. Gross, G.J. McAvay.

Obtaining of funding: C.P. Gross.

Collection and assembly of data: C.P. Gross.

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