The art and science of prognosis in patients with advanced cancer.

Prognosis has always held a fascination for humanity. Many of the earliest medical writings on Mesopotamian cuneiform tablets and Egyptian papyri are treatises about prognostication [1]. From the Hippocratic corpus through the modern era of complex multivariate analyses, the art and science of forecasting and foretelling the course of illnesses have been steadily re®ned [2,3]. In patients with advanced cancer, the ultimate outcome of disease is not often in doubt. But the art and science of prognostication still remains important in this group, as terminally ill patients and their families want and need to know what to expect from the disease and whether palliative services such as hospice care need to be considered. The article by Llobera and colleagues in this issue of the European Journal of Cancer (p 2036±2043) adds to the body of knowledge regarding the prediction of survival time in patients with advanced cancer. The investigators prospectively studied 200 Mallorcan patients with advanced cancer for whom no further antitumour therapy was planned. Oncologists, oncology nurses and family physicians were all asked to provide an estimate of each patient's life expectancy at the time of study enrolment. Periodic assessments were made of Karnofsky performance scores, quality of life indices, and the presence or absence of 21 speci®c symptoms. In a multivariate analysis, low quality of life scores, the presence of asthenia, and a poor prognosis as determined by oncologists were all independent predictors of a short survival time. The authors reported that the predictions of oncologists and oncology nurses correlated with actual survival times. These data are in concert with recent experiences from a North Central Cancer Treatment Group (NCCTG) trial of cancer-related anorexia and cachexia [4]. In the NCCTG study, physicians were asked to place patients into three groups: those with predicted survival times of less than 4 months, 4±6 months or greater than 6 months. In both the NCCTG trial and the Llobera and colleagues study, there was a strong correlation between oncologists' predictions and actual patient survival times, but also a clear trend toward overly optimistic survival estimates. The latter ®nding is corroborated by data from numerous other investigators [3,5±8]. Why does this tendency towards excessive optimism exist? One potential reason is that patients with advanced cancer often appear relatively stable when they come to visit their doctors. A rapid demise may seem implausible, despite an intellectual awareness of the stage of disease and probable outcome. But catastrophic complications such as thromboembolic disease, haemorrhage and infection can intervene at any time, often precipitously accelerating the ®nal phase of an otherwise slowly progressive, chronic illness. It is important to keep such possibilities in mind when formulating a prognosis for a patient with advanced cancer. Even in cases where physicians are able to accurately forecast a dismal prognosis, they may be reluctant to disclose the full truth in order to avoid taking away a patient's hope [2,3]. But hope is a dynamic entity, and it is important for patients to know when hope for a cure or a lengthy survival is a misplaced hope, in order for more appropriate goals to be substituted. The overly optimistic predictions of oncologists are probably responsible, at least in part, for the relatively short time that patients spend in palliative care programmes such as hospice care. The median survival of patients enrolled in the hospice programme at our own institution is 59 days [9], exactly the same survival time as that seen in the population studied by Llobera and colleagues. A signi®cant number of patients are actually in the programme for less than a week.