Real‑World Studies Outshine Single‑Arm Trials for Cancer Survival

Experts from European oncology societies and regulatory bodies compared different study designs to see which gives the strongest evidence that a new cancer drug truly improves survival. They used a method called conjoint analysis to score how convincing each study type was under various conditions, such as the quality of real‑world data and the magnitude of survival benefit. The participants were split into two groups: clinicians who treat patients and regulators who approve drugs. Clinicians tended to favor real‑world studies, giving them a positive rating 48 % of the time, whereas regulators gave such ratings only about 13 %. When a high‑quality real‑world study showed a modest improvement of 1. 5 months in overall survival, its odds of being judged stronger than a single‑arm trial were 2. 7 times higher. If the benefit was larger, at three months, the odds jumped to almost 15 times.In contrast, randomized controlled trials outperformed single‑arm studies by a huge margin: their odds were 36 times higher for a 1. 5‑month benefit and over 350 times higher for a three‑month benefit. The perceived strength of evidence also linked to how much risk regulators were willing to accept for serious side effects. The more convincing the study, the higher the acceptable toxicity threshold. Overall, the research shows that real‑world cohort studies—especially those with high data quality or a sizable survival advantage—are seen as more reliable than single‑arm trials when deciding if a new treatment truly helps patients live longer.