Patients with advanced cancers invariably overestimate their likely survival time and may benefit from ‘best case’ and ‘worst case’ scenarios from their oncologist, research presented at COSA 2018 in Perth suggests.

An analysis of 67 patients with cancers taking part in an advanced care planning trial in NSW found that only 17% were able to estimate their survival time with reasonable accuracy, with 85% providing overestimates.

The study, which involved patients with lung, pancreas, colorectal, breast and urological cancers, found that oncologists’ estimates were more accurate and less biased when it came to patients’ survival times. Multiples of these could be used to provide ranges for most likely, best and worst case scenarios, the researchers from the Department of Cancer Medicine, University of Sydney said.

In their study, 27% of oncologists’s estimates of survival time fell within  33% under or over the observed survival times, with 44% being shorter and 56% being longer.

While the oncologists’ point estimates of survival were inaccurate, simple multiples of these could be used to develop accurate ranges to inform patients. Two out of three patients (64%) lived between half and double the oncologists’ estimated survival time, they noted.

Most patients (60%) said they did not know what their most likely survival time might be, and only around 22% were able to make estimates of best case, worst case and most likely  survival estimates.

Older patients were less likely to provide an estimate for their likely survival time, but were more accurate when they did.

“Oncologists find it difficult to estimate and explain survival time in a way that is accurate and provides hope,” the researchers said.

“Providing patients with survival estimates as worst case, most likely and typical may provide more accuracy than point estimates.”