OBJECTIVES: We estimated the lifetime employment duration (LED), LED loss, lifetime productivity (LP) and LP loss of women with breast cancer (BC) stratified by stages and age.

METHODS: A survival function multiplying a second function, employment status or earnings, over lifetime duration could estimate LED and LP. We recruited 113,169 women with BC diagnosed during 2002-2016 from Cancer Registry and followed until 2018 to estimate their lifetime survival functions through iSQoL2 R package. Their monthly conditional employment-population ratio (EMRATIO) and insured salary were abstracted from National Health Insurance (NHI) until 2017. We extrapolated them based on an association of survival and employment probability with a sex-, age-, and calendar year-matched referents generated from NHI which has a nearly 99.6% coverage rate. The differences in LED and LP between women with BC and the matched referents are the LED loss and LP loss. We also calculated the loss percentages for comparison.

RESULTS: The LED loss of women aged 18-39, 40-44, and 45-49 with stage I were 1.3 year, 0.2 year and 0.3 year (with 6.6%, 1.4%, 2.8% loss), respectively while the LP of some outperformed the matched referents with 0.5%, -5.5% and -6.4% loss, respectively. The LED loss of women aged 45-49 with BC staging above II were 1 year, 3.4 years, and 8 years (with 9.5%, 31.6%, 74.5% loss), respectively while the corresponding LP loss proportions were 6.1%, 31.9%, 75.9%, respectively. For the 18-39 group, the proportions of LED loss were at least three folds if they were diagnosed more advanced than stage II.

CONCLUSIONS: Diagnosing breast cancer at earlier stages by mammography saved productivity loss for our society. The younger the women, the larger the impacts. Future cost-effectiveness analysis could consider this impact for evaluating BC screening program.