Post Mastectomy Radiation for Stage II Breast Cancer Patients with T1/T2 Lesions

Post mastectomy radiation (PMR) is usually recommended for T3 or N2 breast cancer (BC). The role of PMR for stage II BC with T1/T2 lesions remains controversial. The aim of this study was to assess the role of PMR in this subgroup of patients.

A retrospective analysis of a prospectively collected database of all stage II BC patients treated with mastectomy at our institution between the years 2005-2008 was performed. Demographics, disease-free survival rates were compared between the patients receiving radiation vs. those who were not irradiated.

Eighty-two patients underwent mastectomies for stage II disease with a T1/T2 lesion. Twenty-two of those (27%) received PMR. Loco regional recurrence (LRR) occurred only in the non -irradiated (NR) group. A Kaplan Meier analysis of time to LRR in the NR group was performed. Mean time to local failure was 78.9 months, 6% at 3 years and 13% at 5 years. The time to LRR was significantly lower in the estrogen receptor (ER) negative group compared to the ER positive group (64 vs. 82 months, p=0.029). LRR free rate at 5 years was 100% in low grade tumors vs. 53% in high grade tumors, (p=0.001). In a Cox regression multivariate analysis none of those factors maintained significance.

ER negative status, high grade and node negativity were associated with LRR. A prospective trial randomizing stage II BC patients with T1/T2 lesions, negative hormone receptors and high-grade tumors to PMR following mastectomy arm vs. no radiation arm is recommended.