Risk factors associated with breast cancer diagnoses during delivery hospitalizations: A decomposition analysis
Sydney D. Williams, Logan Tom, Timothy Wen, Alexander M. Friedman, Yongmei HuangAbstract
Objective
This study aimed to evaluate trends in breast cancer diagnoses among delivery hospitalizations and to determine the degree to which individual risk factors contributed to changes in breast cancer prevalence over time.
Methods
We conducted a serial cross‐sectional study using data from the Nationwide Inpatient Sample. Delivery hospitalizations among women aged 15–54 years from 2006 to 2022 were included. The primary outcome was a breast cancer diagnosis associated with a delivery hospitalization identified using ICD‐9 and ICD‐10 diagnosis codes. Joinpoint regression was used to evaluate temporal trends in breast cancer, and logistic regression models were employed to identify factors associated with breast cancer prevalence. Multivariate logistic regression decomposition was applied to quantify the contribution of risk factors to the difference in breast cancer prevalence between 2006–2008 and 2020–2022.
Results
A total of 13 million delivery hospitalizations were identified. Breast cancer prevalence increased from 6.4 per 100,000 births in 2006 to 12.3 per 100,000 in 2022 with an average annual percentage change of 4.8% (95% confidence interval [CI], 3.4%, 6.4%). Older maternal age, chronic hypertension, family history of breast cancer, and genetic susceptibility to breast cancer were associated with increased odds of breast cancer diagnoses during delivery hospitalization. From 2006 to 2022, there were significant increases in the proportion of women with older maternal age and chronic conditions. Multivariate logistic regression decomposition analysis indicated that changes in maternal age were the most important determinant of increased prevalence. If maternal age distributions were the same in 2020–2022 as they were in 2006–2008, breast cancer prevalence would be expected to be 58% lower in 2020–2022.
Conclusion
Breast cancer prevalence among the obstetric population has increased over time, with advanced maternal age accounting for more than half of the increase in breast cancer occurrence.