title: Patterns and predictors of breast cancer chemotherapy use in Kaiser Permanente Northern California, 2004-2007.
abstract: Chemotherapy regimens for early stage breast cancer have been tested by randomized clinical trials, and specified by evidence-based practice guidelines. However, little is known about the translation of trial results and guidelines to clinical practice. We extracted individual-level data on chemotherapy administration from the electronic medical records of Kaiser Permanente Northern California (KPNC), a pre-paid integrated healthcare system serving 29 % of the local population. We linked data to the California Cancer Registry, incorporating socio-demographic and tumor factors, and performed multivariable logistic regression analyses on the receipt of specific chemotherapy regimens. We identified 6,004 women diagnosed with Stage I-III breast cancer at KPNC during 2004-2007; 2,669 (44.5 %) received at least one chemotherapy infusion at KPNC within 12 months of diagnosis. Factors associated with receiving chemotherapy included <50 years of age [odds ratio (OR) 2.27, 95 % confidence interval (CI) 1.81-2.86], tumor >2 cm (OR 2.14, 95 % CI 1.75-2.61), involved lymph nodes (OR 11.3, 95 % CI 9.29-13.6), hormone receptor-negative (OR 6.94, 95 % CI 4.89-9.86), Her2/neu-positive (OR 2.71, 95 % CI 2.10-3.51), or high grade (OR 3.53, 95 % CI 2.77-4.49) tumors; comorbidities associated inversely with chemotherapy use [heart disease for anthracyclines (OR 0.24, 95 % CI 0.14-0.41), neuropathy for taxanes (OR 0.45, 95 % CI 0.22-0.89)]. Relative to high-socioeconomic status (SES) non-Hispanic Whites, we observed less anthracycline and taxane use by SES non-Hispanic Whites (OR 0.63, 95 % CI 0.49-0.82) and American Indians (OR 0.23, 95 % CI 0.06-0.93), and more anthracycline use by high-SES Asians/Pacific Islanders (OR 1.72, 95 % CI 1.02-2.90). In this equal-access healthcare system, chemotherapy use followed practice guidelines, but varied by race and socio-demographic factors. These findings may inform efforts to optimize quality in breast cancer care.
authors.affiliation: Department of Medicine, Stanford University School of Medicine, Stanford, CA, USA.
authors.forename: Allison W
authors.initials: AW
authors.lastname: Kurian
authors.forename: Daphne Y
authors.initials: DY
authors.lastname: Lichtensztajn
authors.forename: Theresa H M
authors.initials: TH
authors.lastname: Keegan
authors.forename: Rita W
authors.initials: RW
authors.lastname: Leung
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Shema
authors.forename: Dawn L
authors.initials: DL
authors.lastname: Hershman
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Kushi
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Habel
authors.forename: Tatjana
authors.initials: T
authors.lastname: Kolevska
authors.forename: Bette J
authors.initials: BJ
authors.lastname: Caan
authors.forename: Scarlett L
authors.initials: SL
authors.lastname: Gomez
mesh_terms: D000328:Adult; D000368:Aged; D018943:Anthracyclines / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology; D002140:California / Q000453:epidemiology; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000453:epidemiology / Q000556:secondary; D018275:Carcinoma, Lobular / Q000188:drug therapy* / Q000453:epidemiology / Q000556:secondary; D017024:Chemotherapy, Adjuvant / Q000706:statistics & numerical data; D057286:Electronic Health Records; D005260:Female; D006282:Health Personnel; D006801:Humans; D016015:Logistic Models; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015999:Multivariate Analysis; D017410:Practice Guidelines as Topic; D043823:Taxoids / Q000627:therapeutic use; D047368:Tumor Burden
chemical_list: D018943:Anthracyclines; D000970:Antineoplastic Agents; D043823:Taxoids