Oncologist Use of Reduced Doses of New Systemic Treatments in Patients With Metastatic Cancer

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In a survey study reported in JCO Oncology Practice, Jimenez et al found that half of surveyed oncologists reported sometimes or usually using reduced doses at initiation of a new systemic treatment in patients with metastatic cancer in order to potentially reduce toxicity.

Study Details

The study included an electronic survey of medical oncologists who were U.S. or international members of ASCO who indicated breast, gastrointestinal, or general oncology interest areas in their member profiles. Survey questions addressed experiences with and attitudes towards dose reduction at initiation of a new systemic therapy for patients with metastatic cancer. Among 3,099 eligible oncologists invited to participate, 367 (12%) responded. Use of dose reduction at initiation was categorized as: never; rarely (≤ 10% of the time); sometimes (10%–50% of the time); and usually (≥ 50% of the time).

Key Findings

Among the 367 oncologists, 56.6% reported using dose reduction at initiation ≥ 10% of the time to minimize toxicities. Gastrointestinal specialists were significantly more likely (overall P = .005) to use dose reduction at initiation ≥ 10% of the time (70%) vs breast specialists (50.7%) and generalists (49.6%). In analysis by age, physicians aged 40 to 49 years had the highest rate of use of dose reduction at initiation (62.9%). 

The most frequently cited factors considered important in influencing use of dose reduction at initiation were the patient’s medical condition (97.5%), potential side effects (90.9%), evidence from published studies or guidelines (84.7%), the physician’s prior experience with the drug (76.2%), and patient preference (51%).

Among physicians who dose reduced ≥ 10% of the time, 89% reported discussing potential tradeoffs between efficacy and toxicity with patients.


  • 97.5% of physicians agreed/strongly agreed that dose reduction at initiation can reduce the risk of side effects
  • 72.3% agreed/strongly agreed that the initial dose should align with the patient’s preferences for balancing efficacy and side effects
  • 64.3% agreed/strongly agreed that dose reduction at initiation is acceptable to reduce side effects at the expense of efficacy; physicians aged < 50 years were more likely to agree/strongly agree with this statement vs older physicians (P = .005).

Overall, 89% of physicians expressed strong support for future trials to determine optimal effective dose of treatments rather than maximum tolerated dose.

The investigators concluded, “Oncology practice varies with regard to discussion and individualized selection of starting doses in the metastatic setting. This study demonstrates a need for consideration of shared decision-making regarding initial dose selection and strong support among oncologists for clinical studies to define optimal dosing and best practices for individualizing care.”

Rachel B. Jimenez, MD, of the Department of Radiation Oncology, Massachusetts General Hospital, is the corresponding author for the JCO Oncology Practice article.

Disclosure: Research support for the study was provided by ASCO. For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.