Taxane Treatment in Women with Incident Stage IV Breast Cancer.
Authors: Schneider M. , Zuckerman I. , Pandya N. , McNally D. , Gardner J. , Onukwugha E. , Seal B. , Mullins C. 
Published: December 2010

Introduction: The overall benefit of chemotherapy for late stage breast cancer treatment has been demonstrated in clinical trials and “real world” observational studies, but there is less data on chemotherapy use among older women. In addition, estrogen receptor status can influence treatment decisions. Our objective was to explore the clinical and demographic characteristics of women who received chemotherapy, particularly taxanes, in a large population-based cohort of older patients with incident stage IV breast cancer.Methods: Older women (age 66 and over) diagnosed with incident stage IV breast cancer from 1999 to 2005 were identified in the Surveillance, Epidemiology and End Results (SEER) cancer registries. Treatment-related data were linked from Medicare claims. We limited our analysis to ER negative (ER-) women with the assumption that these women would not be receiving tamoxifen as SEER data do not have complete information on receipt of tamoxifen. Receipt of chemotherapy was identified from claims files. Bivariate analyses were performed to compare clinical and demographic characteristics of those who received taxanes, other chemotherapy, or no chemotherapy.Results: Of 3,820 older women diagnosed with incident stage IV breast cancer, 1,518 women (40%) were identified as ER negative, of whom 247 (16%) were treated with taxanes, 312 (21%) with other chemotherapy, and the remainder received neither. Mean age was 78, 84% of the study cohort was white, 27% were married, and 91% lived in urban areas. Fifty four percent of women had HER2 assays performed. Women who received taxanes were substantially younger (Mean=74, SD=5.49) than those who did not (Mean=80, SD=7.79) and had fewer co-morbidities (measured by Charlson co-morbidity index) (bivariate [see above] p=0.0003) than any other group. Individuals who received taxanes were less likely to be married, receive radiation or undergo surgery. Only 8% of those treated with taxanes had 2 or more medical conditions compared to 18% of those receiving other chemotherapy and 74% of those with no chemotherapy. Treatment groups varied in regard to some medical conditions including CHF, cerebrovascular disease, and dementia. For example, only 8% of those receiving taxanes had CHF, compared to 13% among the 'other chemotherapy' group and 78% among those receiving no treatment (bivariate [see above] p=0.0003). A similar trend was revealed with the other medical conditions, with taxane users consistently presenting with lower prevalence for each condition. Interestingly, no one who had dementia received any chemotherapy.Conclusion: Findings from this descriptive study showed that age and co-morbidity were the most important factors associated with receipt of taxanes as well as of other chemotherapy. However, those who received taxanes were the youngest and evidenced the least comorbidity of the 2 groups. Further study is needed to help inform clinicians in making optimum treatment recommendations for their older female patients with incident advanced breast cancer.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2068.