Younger age is an independent predictor of worse prognosis among Lebanese nonmetastatic breast cancer patients: analysis of a prospective cohort

BACKGROUND: Several retrospective studies have reported that younger age at presentation is associated with a worse prognosis for nonmetastatic breast cancer patients. In this study, we prospectively assessed the association between different baseline characteristics (age, tumor characteristics, mode of treatment, etc) and outcomes among newly diagnosed nonmetastatic Lebanese breast cancer patients. METHODS: We recruited a sample of 123 women newly diagnosed with nonmetastatic breast cancer presenting to American University of Beirut Medical Center. Immunohistochemical, molecular (vitamin D receptor, methylene tetrahydrofolate reductase polymorphisms), and genetic assays were performed. Patient characteristics were compared by age group (<40 and ≥40 years). A Cox regression analysis was performed to evaluate the variables affecting the disease-free survival (DFS). Outcome data were obtained, and DFS was estimated. RESULTS: Among the 123 patients, 47 were 40 years of age or younger, and 76 were older than 40 years. Median follow-up duration was 58 months. Nine out of 47 patients <40 years (19.1%) experienced disease relapse in contrast to four out of 76 patients >40 years (5.2%). A wide immunohistochemical panel included Ki-67, cyclin B1, p53, platelet-derived growth factor receptor, and vascular endothelial growth factor receptor, and did not reveal any significant difference in these markers between the two age groups. Older patients had a larger percentage of Luminal A than younger patients. On multivariate analysis including age, stage, grade, and subtype, only age <40 and stage were significantly associated with shorter DFS with hazard ratios of 4 (p=0.03, 95% confidence interval [CI]: 1.1–13.5) and 3 (p=0.03, 95% CI: 0.8–14.9), respectively. The estimated 5-year DFS for patients >40 years was 90%, and for patients <40 years was 37%. CONCLUSION: Being <40 years old was an independent risk factor for recurrence in this cohort of patients.