[Is there a rationale for regional node irradiation in pN1mi and pN0(i+) breast tumours?]

The advent of sentinel lymph node technique has led to a shift in lymph node staging, due to the emergence of new entities, namely micrometastases and isolated tumour cells. In addition, the therapeutic role of axillary lymph node dissection is more and more questioned and radiotherapy has been shown to be equivalent to complementary axillary lymph node dissection in patients without clinical node involvement. This article looks at the literature in favour of performing axillary irradiation in patients with pN1mi stage breast cancer who have undergone a mastectomy without a complementary axillary lymph node dissection, and in favour of abstention of any further treatment of the axilla in patients with pN0(i+) or pN1mi tumours who have undergone breast conserving surgery and a sentinel lymph node procedure followed by systemic treatment. The impact of regional lymph nodes irradiation in case of axillary involvement 2mm or less is also discussed.