Survival of patients with synchronous brain metastases: an epidemiologicalstudy in southeastern Michigan

Object. It has been suggested that synchronous brain metastases (that is, t hose occurring within 2 months of primary cancer diagnosis) are associated with a shorter survival time compared with metachronous lesions (those occu rring more than 2 months after primary cancer diagnosis). In this study the authors used data obtained from the National Cancer Institute's Surveillan ce, Epidemiology, and End Results program to determine the incidence of syn chronous brain metastases and length of survival of patients in a defined p opulation of southeastern Michigan residents. Methods. Data obtained in 2682 patients with synchronous brain metastases t reated between 1973 and 1995 were reviewed. Study criteria included patient s in whom at least one brain metastasis was diagnosed within 2 months of th e diagnosis of primary cancer and those with an unknown primary source. The incidence per 100,000 population increased fivefold, from 0.69 in 1973 to 3.83 in 1995. The most frequent site for the primary cancer was the lung (7 5.4%). The second largest group (10.7%) consisted of patients in whom the p rimary site was unknown. The median length of survival was 3.2 months. Ther e was no significant difference in the median survival of patients with pri mary lung/bronchus and those with an unknown primary site (3.3 months and 3 .2 months, respectively). Conclusions. Patients who present with synchronous lesions have a poor prog nosis, and the predominant cause of death, in more than 90% of cases, is re lated to systemic disease; however, despite poor median survival times, cer tain patients will experience prolonged survival.