The Increasing Incidence of Breast Cancer in Young Women: A Snapshot of One State's Experience

Purpose To evaluate the differences, by age group, in patient and cancer characteristics in women diagnosed with breast cancer, including stage at diagnosis and variation in treatment (receipt of chemotherapy, type of surgery) related to age, in a state with a higher prevalence of breast cancer in young women. Methods A secondary analysis of data from the population-based New Jersey State Cancer Registry for the years 2011 to 2021. Results A total of 94,443 cases of invasive breast cancer were diagnosed. Over 80% of women under age 40 were diagnosed with invasive cancer. Later stage at diagnosis was found to be significantly higher in the younger age group ( P  > .001), and younger women were more likely to be diagnosed with late stage cancer, or to be metastatic at diagnosis ( P  > .001). Younger women were more likely to receive a mastectomy, a bilateral mastectomy, and chemotherapy as compared to older women ( P  > .001). Conclusions Young women diagnosed with breast cancer in New Jersey often face a late stage diagnosis, which can mean a worse prognosis. This effect is greater for women of low socioeconomic status. As they are excluded from state screening programs, late-stage diagnoses will continue to be reported. Further place-based analyses may help to explain the higher rate of breast cancer in the state and allow for potential prevention measures for this population.