Impact of comorbidity on overall survival and distant recurrence free period of elderly breast cancer patients – a focus cohort study

Abstract

cognition (using FACT scales); and provide DNA samples for APOE genotyping. Z-scores are calculated for each test using the control means and standard deviation as the reference standard. Domain Zscores are calculated as the average of tests in the domain and ageadjusted. Age-adjusted Z-scores are compared by case-control status and groups stratified by cognitive reserve (based on median WRAT scores) and APOE e4 allele carrier status. Relative cognitive deficits are defined as having any domain Z-score ≤ 2 SD or two or more domain Z-scores ≤ -1.5 SD. Results: To date, 162 cases and 160 controls have been recruited and successfully matched. Among the cases, 64.3% are AJCC stage 1, 31.6% stage 2, and 3.5% stage 3. Almost all are estrogen receptor positive (90%) and 14.2% are HER2 positive; 32% have planned chemotherapy, and the remainder will have hormonal or no adjuvant treatment. Cases have greater baseline depression (p = .02) and report lower physical and emotional function than controls (p b .0001). At baseline, 15% of cases and controls demonstrate relative cognitive deficits, with higher rates among those with lower vs. higher cognitive reserve (21.2% vs. 8.2%, p = .001). Cases and controls with less cognitive reserve also have lower mean baseline scores on virtually all cognitive tests and domains than those with higher reserve. However, there were no baseline differences between cases and controls in any domain or in self-reported cognition. Overall, 94% have provided biosamples: 20.6% have an APOE e4 allele (cases 17.4%, controls 25.3%, p = NS), but there are no differences in baseline cognitive domain scores or deficits by APOE status. Conclusion: The TLC study has successfully recruited a well-matched sample of older breast cancer patients and controls. Preliminary analyses do not demonstrate significant pre-treatment differences between cancer patients and controls. Since the groups are comparable at baseline, we are well positioned to assess longitudinal changes in cognition as a function of adjuvant therapy. Understandingwhich older breast cancer patients are vulnerable to cognitive deficits after cancer treatment should contribute to shared decision making about benefits and risks systemic therapy in the growing older cancer population.