Table 2.

Major prognostic factors for patients with oligometastatic cancers evident across multiple studies, colloquially termed the “four aces”

Prognostic factorCommon definitions
Young ageUsually defined as <65 or <70, or analyzed as a continuous variable
Patient fitnessKarnofsky performance status ≥70
Slow-growing cancersMetachronous presentation of oligometastases
Longer disease-free interval between original tumor and development of metastases
Minimal disease burdenPresence of fewer metastatic sites
Single-organ oligometastases
Lack of extracranial disease