Research summary
August 2008
Genetic factors may explain poorer breast cancer survival in younger women
A study has identified gene expression profiles unique to breast tumours in younger women that may explain their poorer prognoses.
Background
Of the 13,000 women diagnosed with breast cancer in Australia each year, about 700 of these women are aged under 40 (less than six per cent). Survival rates are lower for women younger than 40 years than for older women. About 81 per cent of women aged under 40 will be alive five years after their diagnosis compared with 90 per cent of women diagnosed in their 50s and 89 per cent of women diagnosed in their 60s. Breast cancer is known to be more aggressive in younger women compared with older women.
Research findings
An international study has examined the biology that may explain the differing survival rates in younger women and older women with breast cancer by examining 784 early stage breast tumours for distinguishing characteristics.
The researchers defined ‘young’ women as those aged 45 years and younger. ‘Older’ women were defined as those aged 65 and over.
The researchers identified 367 sets of genes that were expressed differently in the young women’s tumours that included genes related to immune function and many signalling pathways related to cancer. The tumours in young women were also characterised by differences in hormone sensitivity. This provided the researchers with insight into a unique biology of breast cancer arising in younger women.
National Breast and Ovarian Cancer Centre comment
This study supports the findings from previous studies showing that age is an independent predictor of worse prognosis in breast cancer cases.
The study provides a genetic rationale for the worse prognostic features seen in younger women and is thought-provoking in relation to implications for the development of both preventative and treatment actions for the future. Further study is required to better understand the biology of breast cancer in younger women before there is any implications for clinical practice.
Sources
Anders CK, Hsu DS, Broadwater G et al. Young age at diagnosis correlates with worse prognosis and defines a subset of breast cancers with shared patters of gene expression. Journal of Clinical Oncology, 26(20) 3324-30.