Salpeter et. al. summarize prognostic factors in cancer and non-cancer diagnoses that are consistently associated with a survival of 6 months or less.
“Despite different cancer characteristics, a fairly universal picture of terminal disease included decreasing performance status, advancing age, weight loss, metastatic disease, disease recurrence, and laboratory abnormalities indicating extensive disease. Most of the prognostic indicators found were continuous, independent risk factors for mortality. We found little evidence that treatment improved survival at these terminal stages, with increased risk for toxicity.”
“Even though advanced noncancer syndromes differ clinically, a universal set of prognostic factors signals progression to terminal disease, including poor performance status, advanced age, malnutrition, comorbid illness, organ dysfunction, and hospitalization for acute decompensation. Generally, a 6-month median survival is associated with the presence of 2-4 of these factors. With few exceptions, these terminal presentations are quite refractory to treatment.”
Salpeter et. al. J Pall Med DOI: 10.1089/jpm.2011.0192; AJMed doi:10.1016/j.amjmed.2011.07.028