Background: Decisions about adjuvant therapy involve trade-offs between possible benefits and harms.
Objective: We sought to determine the survival benefits that clinical investigators would judge as sufficient to warrant treatment with adjuvant sorafenib in the SORCE trial after nephrectomy for apparently localised renal cell carcinoma (RCC).
Methods: A subset of clinical investigators in the SORCE trial completed a validated questionnaire that elicited the minimum survival benefits they judged sufficient to warrant one year of adjuvant sorafenib in scenarios with hypothetical baseline survival times of 5 years and 15 years, and baseline survival rates at 5 years of 65% and 85%.
Results: The 100 participating SORCE investigators had a median age of 42 years, and 74 were male. For one year of sorafenib versus no therapy, the median benefits in survival times the investigators judged sufficient to warrant treatment were an extra nine months beyond five years and an extra 12 months beyond 15 years; the median benefits in survival rates were an extra 5% beyond baseline survival rates of both 65% and 85% at five years. The patients recruited in the SORCE trial by these investigators judged smaller benefits sufficient to warrant adjuvant sorafenib for both survival rate scenarios (p≤0.0001). The survival benefits the investigators judged sufficient to warrant one year of adjuvant therapy with sorafenib for RCC were similar to those of other clinicians considering three months of adjuvant chemotherapy for lung cancer, but smaller than those of clinicians considering six months of adjuvant chemotherapy for breast cancer.
Conclusion: SORCE investigators judged larger benefits necessary to warrant adjuvant sorafenib than their patients. The benefits required by the investigators were similar or smaller than those other clinicians considered sufficient to warrant adjuvant chemotherapy for other cancers. Clinicians should recognise that their patients and colleagues may have preferences that differ from their own when considering the potential benefits and harms of adjuvant treatment.
Keywords: Renal cell carcinoma; adjuvant therapy; decision making; investigators’ preferences; sorafenib.