Breast cancer rates have been rising in younger women – many of whom aren’t yet eligible for screening – and a new study in JAMA Network Open offers a perspective.
Breast cancer mortality has dropped consistently over the last several decades, with a recent study in JAMA attributing the decline to the combination of screening and treatment.
- And a related study by the American Cancer Society found that while cancer mortality has fallen for six of the top 10 cancers, incidence has been rising for breast cancer, particularly among younger women under 50.
The problem is that even the most liberal breast screening guidelines recommend that average-risk women don’t start getting screened until age 40.
- This leaves younger women at risk of developing cancers that may present as more advanced disease.
The new study delves into this phenomenon, with researchers examining data from 218k women ages 20-49 who were diagnosed with invasive breast cancer from 2000-2019. Researchers found that cancer incidence …
- Increased 0.79% annually across all women
- Accelerated “dramatically” starting in 2016
- Rates per 100k women were similar for non-Hispanic Black and White women (71 & 70) across all age groups
- But were sharply lower for Hispanic women (53)
- Rates for Black women 20-29 and 30-39 were the highest among race and age cohorts (8 and 51)
- Rates varied by hormone receptor status
The lower incidence rate for Hispanic women was an intriguing finding that researchers attributed to younger age at the birth of their first child, higher maternal parity, and longer periods of breastfeeding – all factors that may be changing with lower fertility rates.
- The higher incidence rates for younger Black women are particularly problematic as these women also are more likely to present with advanced disease, which leads to higher mortality rates.
The Takeaway
The new study provides background to what’s become one of the more disturbing trends in public health. While incidence rates in younger women are still much lower than in older women, the rise raises the question of whether health interventions such as risk assessment and targeted screening – such as for younger Black women – are necessary.
