Chordoma: incidence and survival patterns in the United States, 1973-1995

Background: Chordoma, a rare tumor arising from notochordal remnants, has been described to date only by single-institution case series or small population-based surveys. Methods: We used data from the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute, 1973-1995, to calculate age-adjusted incidence and survival rates for 400 cases of microscopically confirmed chordoma and to derive information regarding case distribution and risk of second cancer. Results: The age-adjusted chordoma incidence rate (IR) of 0.08 per 100,000 was age-dependent, more common in males (IR 0.10) than females (IR 0.06) and rare among patients aged < 40 years and blacks. Within the axial skeleton 32% of cases were cranial, 32.8% spinal and 29.2% sacral. Young age (< 26 years; p = 0.0001) and female sex (p = 0.037) were associated with greater likelihood of cranial presentation. There was no overall increased risk for second primary cancers after chordoma. Median survival was 6.29 years; 5- and 10-year relative survival rates were 67.6% and 39.9%, respectively. Comparison with other bone sarcomas revealed racial disparities in incidence for the two developmental tumors, chordoma and Ewing's sarcoma. Conclusions: This study provides new data regarding incidence and survival patterns of chordoma in the US. Additional epidemiologic studies are required to elucidate the genetic and environmental determinants underlying this rare, distinctive neoplasm.