Prognosis and adjuvant treatment effects in selected breast cancer subtypes of very young women (<35 years) with operable breast cancer.

BACKGROUND

There is limited knowledge about prognosis of selected breast cancer subtypes among very young women.

PATIENTS AND METHODS

We explored patterns of recurrence by age according to four immunohistochemically defined tumor subtypes: Luminal A and Luminal B (estrogen receptor positive and/or progesterone receptor positive and either human epidermal growth factor receptor 2 (HER2) positive and/or high Ki-67), HER2-positive (and) endocrine receptor absent and Triple Negative, in 2970 premenopausal patients with pT1-3, pN0-3 and M0 breast cancer.

RESULTS

Patients <35 years of age (315, 11%) presented a significantly increased risk of recurrence and death [hazards ratio (HR) = 1.65, 95% confidence interval (CI) 1.30-2.10 and HR = 1.78, 95% CI 1.12-2.85, respectively] when compared with older patients (2655, 89%) with similar characteristics of disease. This was true considering patients with Luminal B [HR = 1.62, 95% CI 1.21-2.18 for disease-free survival (DFS) and HR = 2.09, 95% CI 0.96-4.53 for overall survival (OS)] and with Triple Negative (HR = 2.04, 95% CI 1.11-3.72 for DFS and HR = 2.20, 95% CI 1.10-4.41 for OS) breast cancer, observing the highest risk of recurrence in the younger patients with HER2-positive breast cancer (HR = 2.37, 95% CI 1.12-5.02) when compared with older patients.

CONCLUSIONS

Very young patients with Triple Negative, Luminal B or HER2-positive breast cancer have a worse prognosis when compared with older patients with similar characteristics of disease.