Survivorship patterns of a large nationwide cohort of elderly veterans with colorectal cancer

Abstract

13525 Background: Administrative databases are not designed to permit cancer researchers to readily follow patients from the period pre-diagnosis through initial curative intent treatment, adjuvant therapy, post-treatment follow-up, to either death or loss to follow-up. One major hurdle to cancer research using such databases has been the lack of data such as stage at diagnosis, and histopathologic type and grade. A second major hurdle is that many patients use more than one system of care, in this instance, Department of Veterans Affairs (VA) and Medicare-reimbursed care. These dual users would be inaccurately represented in the analysis if only one source of data were analyzed. Methods: A retrospective analysis of 13 years of nationwide Medicare and VA inpatient and institutional outpatient data beginning with the three years pre-diagnosis (1986–1990) through a minimum of five years post-diagnosis (1994–1998) was conducted. Death data were available through June 2005. Data were also extracted from tumor registry files, Computerized Patient Record System Files, and paper medical records at each VA. The population studied included all VA patients diagnosed with colorectal cancer and surgically treated for cure during the five-year period 1989–1993, who were Medicare-eligible at diagnosis, and survived the index admission. Results: Of the 6612 patients treated with curative intent during the five-year period, 4924 (74%) could be staged. Of these, 4551 (92%) were deemed eligible for the study. Of the eligible patients, 77% were diagnosed with colon cancer and 23 percent with rectal cancer. The majority (89%) had adenocarcinoma. The histopathologic grade was moderately differentiated for 54% and well differentiated for 19%. As of June 2005, 77% had died. Including all stages (0- IV), the average survival in months after treatment was 86 (median=61). Survivorship differed significantly by stage at diagnosis (p < .001). Conclusions: This rich database provides a wealth of data for subgroup analyses of survivorship, recurrence patterns, and health services utilization patterns within and across systems of care. Identifying predictors of survivorship within subgroups of this population is currently under way [Table: see text]