Oncologists' Perspectives on Individualizing Dose Selection for Patients With Metastatic Cancer

Treatment goals for patients with metastatic cancer include prolongation and maintenance of quality of life. Patients and oncologists have questioned the current paradigm of initial dose selection for systemic therapy; however, data on oncologists' dose selection strategies and beliefs are lacking.

We conducted an electronic international survey of medical oncologists who treat patients with breast and/or gastrointestinal cancers. Survey questions addressed experiences with, and attitudes toward, dose reduction at initiation (DRI) of a new systemic therapy for patients with metastatic cancer.

Among 3,099 eligible oncologists, 367 responded (response rate 12%). Most (52%) reported using DRI at least 10% of the time to minimize toxicities. Gastrointestinal specialists were more likely to report DRI ≥ 10% of the time (72% v 50% of generalists and 51% of breast specialists, P < .005). Of those who dose reduced ≥ 10% of the time, 89% reported discussing potential tradeoffs between efficacy and toxicity with patients. Overall, 65% agreed it is acceptable to lower starting doses to reduce side effects even if it compromises efficacy; younger clinicians were more likely to agree (P < .005). There was strong support (89%) for future trials to determine optimal effective, rather than maximum tolerated, dose.

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.