Prevalence and Safety of Off-Label Use of Chemotherapeutic Agents in Older Patients With Breast Cancer: Estimates From SEER-Medicare Data

J Natl Compr Canc Netw. 2016 Jan;14(1):57-65. doi: 10.6004/jnccn.2016.0007. Epub 2016 Jan 5.


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.

Patients and 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / adverse effects
  • Antineoplastic Agents / therapeutic use*
  • Breast Neoplasms / diagnosis
  • Breast Neoplasms / drug therapy*
  • Breast Neoplasms / epidemiology*
  • Cohort Studies
  • Databases, Factual
  • Emergency Service, Hospital
  • Female
  • Hospitalization
  • Humans
  • Medicare
  • Neoplasm Staging
  • Off-Label Use*
  • Prevalence
  • SEER Program
  • United States / epidemiology


  • Antineoplastic Agents