Incident malignancies among older long-term breast cancer survivors and an age-matched and site-matched nonbreast cancer comparison group over 10 years of follow-up

The Cancer Research Network: a platform for epidemiologic and health services research on cancer prevention, care, and outcomes in large, stable populations

PURPOSE

The ability to collect data on patients for long periods prior to, during, and after a cancer diagnosis is critical for studies of cancer etiology, prevention, treatment, outcomes, and costs. We describe such data capacities within the Cancer Research Network (CRN), a cooperative agreement between the National Cancer Institute (NCI) and organized health care systems across the United States.

METHODS

Data were extracted from each CRN site's virtual data warehouse using a centrally written and locally executed program. We computed the percent of patients continuously enrolled ≥1, ≥5, and ≥10 years before cancer diagnosis in 2012-2015 (year varied by CRN site). To describe retention after diagnosis, we computed the cumulative percentages enrolled, deceased, and disenrolled each year after the diagnosis for patients diagnosed in 2000.

RESULTS

Approximately 8 million people were enrolled in ten CRN health plans on December 31, 2014 or 2015 (year varied by CRN site). Among more than 30,000 recent cancer diagnoses, 70 % were enrolled for ≥5 years and 56 % for ≥10 years before diagnosis. Among 25,274 cancers diagnosed in 2000, 28 % were still enrolled in 2010, 45 % had died, and 27 % had disenrolled from CRN health systems.

CONCLUSIONS

Health plan enrollment before cancer diagnosis was generally long in the CRN, and the proportion of patients lost to follow-up after diagnosis was low. With long enrollment histories among cancer patients pre-diagnosis and low post-diagnosis disenrollment, the CRN provides an excellent platform for epidemiologic and health services research on cancer incidence, outcomes, and costs.

Comprehensive evaluation of the incidence of late effects in 5-year survivors of breast cancer

Late effects of breast cancer affect the quality of survivorship. Using administrative data, we compared the occurrence of almost all ICD9 codes among older breast cancer survivors to that among a matched comparison cohort to generate new hypotheses. Breast cancer patients 65 years or older diagnosed 1990-1994 in 6 integrated care settings and who survived at least 5 years were matched with a cohort of women without a history of breast cancer on care setting, age, and calendar time. We collected data on the occurrence of incident ICD9 codes beginning 6 years after the breast cancer diagnosis date and continuing to year 15, and comparable data for the matched woman. We calculated hazard ratios (HRs) and 95 % confidence intervals associating breast cancer survivorship with incidence of each ICD9 code. We used semi-Bayes methods to address multiple comparisons. Older breast cancer survivors had about the same occurrence of diseases and conditions 6-15 years after breast cancer diagnosis as comparable women. The median of 564 adjusted HRs equaled 1.06, with interquartile range 0.92-1.3. The distribution of HRs pertaining to cancer-related ICD codes was shifted toward positive associations, and the distribution pertaining to cardiovascular-related ICD codes was shifted toward negative associations. In this hypothesis-scanning study, we observed little difference in the occurrence of non-breast cancer-related diseases and conditions among older, long-term breast cancer survivors, and comparable women without a history of breast cancer.