Relative lack of conditional survival improvement in young adults with cancer.

Cancer prognosis is usually reported in terms of survival from time of diagnosis. For patients surviving a period of time after diagnosis, conditional survival (CS) accounts for changing risk over time. This report provides information on how CS in cancer patients changes as a function of age at diagnosis. Using data from the US Surveillance, Epidemiology and End Results database, we examined survival for patients diagnosed between 1973 and 2002. The average annual percent change (AAPC) in CS during the first 5 years after diagnosis was evaluated for the 14 most common cancers occurring in young adults, defined as 15- to 39-year-olds, and how they compared with cancers that are more common in older and younger patients. For all cancers, young adult patients had less CS improvement over time than younger or older patients, and this difference was most pronounced in those aged 20 to 29 years (45% below the mean). Eleven of the 14 most common cancers in 15- to 39-year-olds either had a lower CS improvement after diagnosis than either younger or older patients, or than just the older patients. Young adults with leukemia had the greatest improvement in CS over time. In conclusion, young adults with cancer have not enjoyed the same improvement in CS over time compared with other age groups. Explanations for this deficit include the biologic nature of the type of cancers in young adults and less effective therapies for patients in the age group. Regardless of the reasons, the deficit is yet another challenge faced by young adult patients that merits further study.