(CTN News) – JAMA Network Open published a study January 26 showing an increase in breast cancer incidence rates among younger women.
Non-Hispanic Black women ages 20 to 29 and 30 to 39 had higher incidence rates than their Hispanic counterparts. The incidence rate was also higher for estrogen receptor (ER)-positive, stage I, and stage IV tumors.
The findings of Toriola and colleagues “underline the need for further research into breast cancer risk factors among young women and possible prevention strategies.”.
In young women with breast cancer, the prognosis is less favorable, and the cancers tend to be more aggressive biologically. Mammography screening is not recommended for women under the age of 40.
Young women’s trends are also affected by period and cohort effects, according to the researchers.
Toriola and co-authors investigated breast cancer incidence among young U.S. women (ages 20 to 49) as part of the Surveillance, Epidemiology, and End Results (SEER) program. Race and ethnicity of patients, hormone receptor status, tumor stage, and age at diagnosis were taken into account when analyzing these trends.
The data was collected from 217,815 eligible women. There were 1,485 American Indians or Alaska Natives, 25,210 Asians and Pacific Islanders, 27,112 non-Hispanic Blacks, 37,048 Hispanics and 126,960 non-Hispanic whites. Additionally, 61.5% of the women were diagnosed with an ER+/progesterone receptor (PR)+ tumor and 37.6% with a stage I cancer.
The annual percent change in invasive breast cancer incidence was 0.79 over the study period.
Age-standardized incidence rates showed an increase for ER+/PR+ (AAPC, 2.72) and ER+/PR− tumors (AAPC). In addition, it observed decreasing trends for both ER−/PR+ (AAPC, −3.25) and ER−/PR− tumors (AAPC, −0.55).
Age-adjusted incidence rates were 70.7 per 100,000 for non-Hispanic Black women and 69.7 per 100,000 for non-Hispanic white women. The incidence ratios for black women ages 20 to 29 and 30 to 39 were higher than for non-Hispanic white women ages 1 and 1. Incidence rates for black women aged 40 to 49 were 0.96 points lower than those for white women at the same age.
Lastly, the team found that incidence rates increased for cancers in stages I and IV, while decreasing for cancers in stages II and III.
A breast cancer risk assessment should be performed at an early age for Black women based on the results of the study. Women at high risk should undergo targeted screening earlier if they undergo early risk assessments.
Several approaches will be required to address this trend, according to Adetunji Toriola, MD, PhD.
With detailed knowledge of what has worked for reducing estrogen receptor-negative tumors, we can draft prevention efforts to reduce estrogen receptor-positive tumors,” he told AuntMinnie.com. The knowledge that has led to the decline in estrogen receptor-negative tumors can be applied and implemented to reduce the incidence of estrogen receptor-positive tumors.”
Next, the team plans to examine possible factors driving rising rates.
Toriola is particularly interested in why breast cancer rates are higher among non-Hispanic Black women before the age of 40, but not after. In addition, we are investigating biological mechanisms that may explain racial differences in incidence rates over time.”