These findings from the Norwegian Breast Cancer Screening Program were recently published in Breast Cancer Research.
Tumor growth is an important consideration in the planning of screening programs, clinical trials, and cause-and-effect studies. Though previous studies have measured tumor growth among small, select populations, researchers in the current study monitored tumor growth among a large population. Newer estimating procedures were utilized, which incorporated data from mammography screening tests.
Nearly 400,000 women, ages 50–69, were enrolled in the study.
- Results indicated that tumor growth rate varied considerably from woman to woman, with 5% of tumors taking less than 1.2 months to grow 10mm in diameter and another 5% using more than 6.3 years.
- The overall average was estimated at 1.7 years to grow 10mm in size; this time period appeared to increase with age.
- Further analysis revealed that the likelihood of detection increased sharply with tumor size, going from 26% at 5mm to 91% at 10mm.
When compared with previous models for tumor progression, this model utilizing mammography data was found to be increasingly more accurate in estimating tumor size.
Researchers concluded that screening mammography, along with tumor measurements, can provide reliable estimates of tumor growth and tumor size among women. However, breast cancer tumor growth rates vary substantially among women, particularly among younger and older women.
Reference: Weedon-Fekjaer, H., Lindqvist, B., Aalen, O., et al. Breast cancer tumor growth estimated through mammography screening data. Breast Cancer Research. 2008; (10): R41. doi 10.1186/bcr2092.