Doctors get only 20-30% of lifespan predictions of cancer patients accurate, says study
Oncologists are replacing the inaccurate older method of giving patients an average survival time with the three-scenario approach.
Many advanced breast cancer patients want to know how long they are likely to live and count on doctors for that. But doctors often struggle, predicting survival accurately only 20 to 30% of the time, according to Dr. Belinda Kiely, medical oncologist and senior research fellow at the University of Sydney, Australia.
Speaking at the Advanced Breast Cancer Fifth International Consensus Conference (ABC5) in Lisbon, Dr. Kiely said, “Every week in my clinic, I meet women of all ages with advanced breast cancer and they frequently ask: ‘How long have I got?’ They have very practical concerns and questions that they want help with; for example, they might want to know whether they should cancel a planned holiday, whether they will be able to attend their daughter’s wedding, or whether they should stop working or sell their house."
The reason doctors get the estimate wrong, according to Dr. Kiely, is because they provide patients with average survival time. She says, "Oncologists are sometimes unsure about how to help. They may worry about how much a patient wants to know, whether it's possible to give accurate information and how best to talk about this without destroying hope."
Chair of the conference, Dr. Fatima Cardoso, Director of the Breast Unit of the Champalimaud Clinical Centre in Lisbon, Portugal, says: “Research shows that patients who discuss these issues with their doctor have better quality of life, are less likely to undergo aggressive end-of-life resuscitation and are less likely to die in the hospital. But at the moment, we also know that many patients are not having these conversations."
Doctors source most of the information on survival times for advanced breast cancer from clinical trials. Information from these trials can be misleading because patients meet specific eligibility criteria: they are younger, fitter, and have fewer other health problems, and therefore often live longer than the patients doctors see in everyday practice, says Dr. Kiely.
"Providing patients with a single number estimate of the average survival time is rarely accurate and conveys no hope of possible longer survival time. Instead, we have devised a method that helps doctors calculate the best-case, worst-case and typical survival times for individual patients," says Dr. Kiely.
Dr. Kiely's method for calculating the three scenarios has been tested and proven reliable in several studies. It involves doctors estimating the expected survival time for a patient, dividing it by four to get the worst-case scenario and multiplying it by three to get the best-case scenario. The typical scenario is between a half and two times the doctors' estimated survival.
In their survey, Dr. Kiely and team found that patients preferred the three scenarios - best, worst and typical - which was more helpful, easier to understand and more reassuring to the single number average survival estimate.
Additionally, the method proved resourceful to the 33 oncologists who were part of the trail. When these oncologists provided their patients with a printed one-page summary of their individual best-case, typical, and worst-case scenarios, 91% of the patients said they found the printed information helpful. And 88% said it helped them make plans and improved their understanding, while 77% of patients said the scenarios were the same or better than they had expected.
"If we tell a patient that her estimated median survival time is six months, that conveys no hope of possible longer survival, even though she has a 50% chance of living longer. On the other hand, providing three scenarios helps patients prepare for the possible worst-case and, at the same time, hope for the possible best-case. This is more helpful for patients making plans and decisions for the future", says Dr. Kiely.
Dr. Kiely and her colleagues are now promoting the 'three-scenario' approach with oncologists in Australia and hope to encourage colleagues from around the world to do the same.
Cardoso, adds, “Most patients with advanced cancer want some information about how long they are likely to live, although many say they find it difficult to ask this question. The onus is on us as oncologists to start such conversations with our patients. This tool for calculating and sharing the three scenarios gives doctors the help they need to communicate with patients in a realistic and helpful way.”