Radiotherapy following mastectomy: indication and contraindication of chest wall irradiation

To determine in which cases radiotherapy of the chest wall following mastectomy is indicated, based on the local recurrent rate in patients with locally advanced breast cancer.

From 1984 until 1994, 105 patients who had four or more histopathologically confirmed axillary nodes metastases, or T3-4Nany, were subjected to mastectomy and were administered radiotherapy postoperatively using the hockey-stick field, which included the ipsilateral supraclavicular fossa and internal mammary nodes, except the chest wall. Median age was 51 years old (range, 23 to 82 years old). Eighty-five patients underwent radical mastectomy, 18 modified radical mastectomy, and 2 extended radical mastectomy. Fraction size was 2 Gy/day, the weekly fraction size was 10 Gy and the total dose ranged from 44 Gy to 54 Gy (median 50 Gy). Seventy-four patients were administered adjuvant chemotherapy, and 61 patients were administered hormone therapy.

The 5-year disease-free survival rates of the whole study population were 66%. The 5-year chest wall recurrence rates were 10%. The 5-year chest wall recurrence rates of the patients who had no vascular invasion (n = 19) and the patients who had definite vascular invasion (n = 38) were 0% and 24%, respectively (p = 0.036). All the patients who presented chest wall recurrence had four or more axillary nodes metastases. Nine of the 10 patients who presented chest wall recurrence had definite vascular invasion, while there was no information about vascular invasion for the remaining patient. Factors such as age, pathological subtypes, tumor location, estrogen receptors, extent of resection, chemotherapy, and hormone therapy did not influence the development of chest wall recurrence.

Among patients with breast cancer who have four or more positive axillary nodes or T3-4Nany, those who have no vascular invasion or less than 4 axillary nodes metastases do not need to be subjected to chest wall irradiation after radical mastectomy.