Breast cancer incidence rates vary by age and location. BreastCancer.org reports that breast cancer incidence rates in the United States began decreasing in 2000 after increasing for the previous two decades. Some researchers believe the decrease was partially due to the reduced use of hormone replacement therapy (HRT). Even if breast cancer incidence rates in the U.S. are down overall, researchers at Washington University School of Medicine in St. Louis have found diagnoses of breast cancer have increased steadily in women under age 50 over the past two decades. For most women, regular breast cancer screening does not begin until at least age 40, so younger women diagnosed with breast cancer tend to have later-stage tumors and a more advanced disease. Similar findings have been noticed in Canada. An Ottawa-based study published in the Canadian Association of Radiologists Journal found that rates of breast cancer in women as young as their twenties have been increasing. The research team behind the study discovered a 45 percent increase in cases over the past 35 years. Many women have no identifiable risk factors prior to diagnosis, so what is fueling the increase remains a mystery.
T he American Cancer Society reports that approximately
breast cancer cases can be attributed to potentially modifiable risk factors. That finding, cited in the organization’s “Breast Cancer: Facts & Figures, 2022-2024” report, means as many as three in 10 breast cancer diagnoses in postmenopausal women may have been attributable to variables within patients’ control. The ACS notes such variables may have included body weight, alcohol consumption and physical activity levels. The same report also notes that certain modifiable risk factors accumulate over the course of a woman’s life, meaning both postmenopausal women and younger women could potentially lower their risk for breast cancer by making a concerted effort to achieve and maintain a healthy body weight, reduce alcohol consumption and embrace a physically active lifestyle.