title: Prevalence and Safety of Off-Label Use of Chemotherapeutic Agents in Older Patients With Breast Cancer: Estimates From SEER-Medicare Data.
abstract: BACKGROUND
  Prescribing drugs outside of the label indication is legal and may reflect standard practice; however, some off-label use may be inappropriate. This study measured the prevalence and safety of off-label use both in accordance with practice guidelines and inconsistent with practice guidelines in older patients with breast cancer.
  
  
  METHODS
  The SEER-Medicare data set was used to identify women diagnosed with breast cancer. Intravenous chemotherapy was identified using Medicare claims and classified as either on-label, off-label but included in the NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Breast Cancer ("off-label/supported"), or off-label and not included in the NCCN Guidelines ("off-label/unsupported"). Hospitalization/emergency department (ED) admission rates were compared.
  
  
  RESULTS
  A total of 13,347 women were treated with 16,127 regimens (12% of women switched regimen); 64% of regimens were off-label/supported, 25% were on-label, and 11% were off-label/unsupported, and hospitalization/ED admission occurred in 27%, 25%, and 32% of regimens, respectively (P<.0001). Drugs never included in the NCCN Guidelines for Breast Cancer accounted for 19% of off-label/unsupported use (1% of total use).
  
  
  CONCLUSIONS
  Off-label use without scientific support was not common, whereas 64% of use was off-label/supported, reflecting the fact that widely accepted indications are often not tested in registration trials. Off-label/supported use will likely increase as more drugs are expected to have activity across cancer sites, and therefore understanding the implications of such use is critical.
authors.affiliation: From the Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Anne A
authors.initials: AA
authors.lastname: Eaton
authors.affiliation: From the Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Camelia S
authors.initials: CS
authors.lastname: Sima
authors.affiliation: From the Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, New York.
authors.forename: Katherine S
authors.initials: KS
authors.lastname: Panageas
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D015331:Cohort Studies; D016208:Databases, Factual; D004636:Emergency Service, Hospital; D005260:Female; D006760:Hospitalization; D006801:Humans; D006278:Medicare; D009367:Neoplasm Staging; D056687:Off-Label Use; D015995:Prevalence; D018426:SEER Program; D014481:United States / Q000453:epidemiology
chemical_list: D000970:Antineoplastic Agents