Few women with metastatic breast cancer live five years or longer, and predictors of long-term survival are not well understood. Researchers from the University of Pittsburgh Medical Center (UPMC) in Pennsylvania identified demographic- and disease-specific factors related to survival and presented their findings at the .
Researchers included 313 women initially diagnosed with breast cancer since 1999 at Magee-Womens Cancer Program at UPMC Hillman Cancer Center. The cohort included 122 long-term survivors (defined as at least a five-year survival from diagnosis) and 191 short-term survivors (defined as no more than two-year survival from diagnosis). Based on medical records, researchers assessed stage at initial diagnosis, body mass index (BMI), Charlson comorbidity index (CCI), age, menopausal status at initial diagnosis, tumor receptor status at initial diagnosis, site of initial metastases, time to recurrence between initial diagnosis and metastatic disease, household income, race, employment status, and partner status.
Factors associated with long-term survival included (p < 0.05):
- Younger age
- Estrogen receptor-positive disease
- Progesterone receptor-positive disease
- Human epidermal growth factor receptor 2-positive disease
- Lower CCI
- Premenopausal at initial diagnosis
- Lower rates of visceral metastases
- Higher household income
- Positive partner status
Premenopausal status at initial diagnosis remained associated with long-term survival after adjusting for stage at initial diagnosis, tumor receptor status, and CCI (odds ratio [OR] = 1.96; 95% confidence interval [CI] = 1.02–3.79). Compared to short-term survivors, long-term term survivors were diagnosed with de novo metastatic disease significantly more often, and this remained significant after adjusting for age, tumor receptor status, and CCI (OR = 3.0; 95% CI = 1.6–5.4).
Time to recurrence between initial diagnosis and metastatic disease, BMI, race, and employment status did not affect survival.