Estimating survival in advanced cancer: a comparison of estimates made by oncologists and patients.

Purpose: To compare estimates of expected survival time (EST) made by patients with advanced cancer and their oncologists.
Methods: At enrolment patients recorded their "understanding of how long you may have to live" in best-case, most-likely, and worst-case scenarios. Oncologists estimated survival time for each of their patients as the "median survival of a group of identical patients". We hypothesized that oncologists' estimates of EST would be unbiased (~ 50% longer or shorter than the observed survival time [OST]), imprecise (< 33% within 0.67 to 1.33 times OST), associated with OST, and more accurate than patients' estimates of their own survival.
Results: Twenty-six oncologists estimated EST for 179 patients. The median estimate of EST was 6.0 months, and the median OST was 6.2 months. Oncologists' estimates were unbiased (56% longer than OST), imprecise (27% within 0.67 to 1.33 times OST), and significantly associated with OST (HR 0.88, 95% CI 0.82 to 0.93, p < 0.01). Only 41 patients (23%) provided a numerical estimate of their survival with 107 patients (60%) responding "I don't know". The median estimate by patients for their most-likely scenario was 12 months. Patient estimates of their most-likely scenario were less precise (17% within 0.67 to 1.33 times OST) and more likely to overestimate survival (85% longer than OST) than oncologist estimates.
Conclusion: Oncologists' estimates were unbiased and significantly associated with survival. Most patients with advanced cancer did not know their EST or overestimated their survival time compared to their oncologist, highlighting the need for improved prognosis communication training. Trial registration ACTRN1261300128871.