In the British Medical Journal this week, UK researchers present findings from an effort to develop predictor models to improve prognostication for advanced cancer patients. The researchers analyzed data from 1,018 patients with locally advanced or metastatic cancer, who were no longer being treated. They found that 11 core variables — pulse rate, general health status, mental test score, performance status, presence of anorexia, presence of any site of metastatic disease, presence of liver metastases, C reactive protein, white blood count, platelet count, and urea — independently predicted both two-week and two-month survival. The team also found four variables that had prognostic significance only for two-week survival and eight variables that predicted two-month survival. After creating predictor models using these variables and applying them to two groups of cancer patients, the team found that its models "performed as well as, or better than, clinicians' estimates of survival."
In a related editorial in the British Medical Journal, Memorial Sloan-Kettering Cancer Center's Paul Glare says that while prognostic tools are important for helping to determine patient survival, they shouldn't be applied blindly. When the Lockerbie bomber was released from prison in 2009, it was partly because his doctors had said he only had a few months to live because of his advanced prostate cancer — however, he is still alive today, Glare says. Prognosis is a "new science" in palliative care, he adds, and it involves both formulating the prediction and communicating it to the patients. There is guidance available for physicians who want to determine a prognosis, but some are inaccurate. The above study overcomes many of the difficulties of previous methodologies, Glare says, but the downside is that the new models are too difficult to use at the bedside and require some calculation. "Ultimately, even a state of the art prognostic tool ... will often be inaccurate," Glare says. "Until this inherent inaccuracy is mitigated, doctors will continue to resist prognosticating; those who do will be scorned by their colleagues and accused of 'playing God.'"