OBJECTIVES : To examine absolute disparities in stage IV cancer and quantify potential benefits of detection before metastasis for US subpopulations defined by sex and race/ethnicity.

METHODS : Annual cancer incidence and five-year probabilities of cancer deaths were obtained from the Surveillance, Epidemiology and End Results (SEER) Program for persons aged 50-79 diagnosed with invasive cancer between 2006-2015 for eight subpopulations defined by sex and race/ethnicity (Hispanic, non-Hispanic: African-American, Asian/Pacific Islander, White). Hypothetical five-year deaths and percentage deaths averted were calculated under two scenarios: (1) death rates of stage IV cancers were assigned mortality rates associated with stage III detection, and (2) death rates were assigned for stage IV as a mix of stage I, II, and III.

RESULTS : The proportion of all cancer that was metastatic was generally similar in all subpopulations (16-21%). Case-mix adjusted probability of death within five years was ~79% with stage IV and ~35% with any stage diagnosis, though absolute numbers of deaths varied between groups. Among males, Asian/Pacific Islanders had the lowest (177) and African-Americans the highest (337) incidence of stage IV cancer per 100,000. Among females, Asian/Pacific Islanders had the lowest (117) and African-Americans the highest (203) incidence of stage IV cancer per 100,000. When hypothetical 5-year deaths were calculated using scenario 1, ~13% of all cancer deaths were averted across all groups; in African-Americans, this corresponded to 56 females and 80 males per 100,000. In scenario 2, ~21% of all deaths were averted, corresponding to 91 African-American females and 126 African-American males.

CONCLUSIONS : This model predicts that detection of cancer before metastasis could result in comparable relative reductions in mortality across the eight subpopulations, but that the absolute number of deaths averted would be highest among African-Americans, who have the highest incidence of stage IV cancer.