Scientists have known for a while that young women with breast cancer have a poor prognosis. It was thought to be because younger women were diagnosed later, with more advanced disease. The study set out to see if youth on its own was a factor for poor prognosis.
Researchers analysed the American SEER (Surveillance, Epidemiology, and End Results) database of over 45,000 women with breast cancer. All women with early stage breast cancer (stage 1) were included in the study and the various age groups were compared. The results were surprising and indicated that being young was an independent indicator of poor survival - regardless of other factors known to be predictive of outcomes in older women such as tumour size, location, hormone receptor status, race, or treatment.
In fact the odds of dying from breast cancer rather than any other disease increased by 5% for every year that a women was under 45 when diagnosed. For example, a women who was diagnosed with breast cancer at age 35 was 50% more likely to die of the disease. The 10-year overall survival probability of a 30-year old patient (85%) was equal to that of a 60-year old, indicating a considerably reduced life expectancy in young patients.
S. Aebi, leading author of the study comments, "These findings suggest that age in young women, more than any other factor affects the chances of survival. It is very important now to carry on more research and analyse what makes the tumours in young women different – what causes these women to die."
Breast cancer in the under 40's is rare, making up around 5% of all cases. However the impact of the disease can be hard for young women, who often have young children or want to start a family of their own. Improving survival rates would make a big difference to these women.
For further information please contact:
Stéphanie Makin, Tonic Life Communications, stephanie.makin@toniclc.com
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ED4 Breast cancer under 40
Young age is a poor prognostic factor in women with stage I breast cancer
S. Aebi1, M. De Ridder2, G. Vlastos3, V. Vinh-Hung2, G. Storme2
1University Hospital, Medical Oncology, Bern, Switzerland
2AZ-VUB, Oncologisch Centrum, Jette, Belgium
3Hopital Universitaire, Gynecologie Oncologique, Geneve, Switzerland
Background
Breast cancer is rare in young women, only 2%–5% are diagnosed at age 35–40 or less. However, in these young patients, breast cancer is associated with poor prognosis. It has been extensively discussed that young age is not an independent prognostic factor, but correlates with more advanced disease stage at presentation and therefore with worse prognosis.
Objective
The aim of this study is to investigate how age relates with survival outcome in a restricted group of patients presenting with early stage disease, in order to avoid confounding by advanced stages.
Material and methods
Women who were diagnosed between 1988 and 1997 with histologically confirmed unilateral stage I breast cancer (pT1N0M and who underwent lumpectomy or mastectomy with axillary dissection (1–50 nodes examined) were selected from the US Surveillance, Epidemiology, and End Results 9-registries database release 2004. Kaplan-Meier survival estimates were computed as a function of overlapping age intervals from 20 to 95 years. Odds of breast cancer death were computed relative to risk of death from other causes. Multivariate analysis of overall survival (OS) and breast cancer specific survival (BCSS) I patients <45 years included tumor size, location, number of examined lymph nodes, histology, grade, hormone receptor status, marrital status, race, registry area, year of diagnosis, type of surgery, and radiotherapy as covariates.
Results
There were 47,590 records available. The OS (Figure 1: dashed curve) showed a biphasic shape, with decreased 10-year O from 90% to 80% in very young patients (<35 years) and in older patients (>60 years). As an example, the 10-year OS probability of a 30-year old patient (85%) is equal to that of a 60-year old patient, indicating a considerably reduced life expectancy in these young patients. In line, the BCSS (Figure 1: solid curve) closely parallels the OS in patients <45 years, showing that the reduced life expectancy in young patients was almost entirely attributable to breast cancer. Considering the odds of death, the risk of dying from breast cancer outweighed the risk of dying from any other cause in young patients (od 2–9 in patients <45 years, Figure 2). Multivariate analysis by OS outcome showed a hazard ratio (HR, adjusted by other covariates) for age of 1.03, i.e. 3% relative increased risk of death per each year younger than 45 (P=0.006). By BCSS outcome, the HR was 1.05, i.e. 5% relative increased risk of BC death per each year younger than 45 (P=0.0001).
Discussion
Breast cancer represents a severe disease burden in young women diagnosed with early stage breast cancer. Conventional prognostic factors are insufficient to account for the poor prognosis associated with young age. We argue that molecular signatures are required to investigate the biological mechanisms underlying breast carcinomas occurring in different age groups.