BALTIMORE--Irradiation of the chest wall following mastectomy has had an up and down history as breast cancer therapy. Now, says Allen S. Lichter, MD, director of Radiation Oncology, University of Michigan Medical Center, it is time to take another look at its value for patients with local or regional disease after surgery.
About one third of all first failures are on the chest wall, Dr. Lichter said, and the rate is even higher for node-positive patients. "I think we need to take this off the shelf again and start to use it," he said, urging new randomized trials.
In his presentation at a conference on neoplastic disorders, sponsored by Johns Hopkins Oncology Center, Dr. Lichter, cited studies during the last 40 years showing that chest wall irradiation significantly reduces the number of chest wall failures and increases disease-free survival. However, the procedure appears not to improve overall survival and may actually decrease it, due to an excess rate of cardiac deaths.
These ambiguous results, he said, are due both to the nature of the disease and the design of the trials.
In retrospect, Dr. Lichter said, studies beginning with the Manchester Trial (1949-1955) were clouded by uneven radiotherapy techniques, mixed groupings of patients (node positive and negative, premenopausal and postmenopausal), hormonal therapy in some cases, and small sample sizes.
Regarding the disease itself, Dr. Lichter would divide patients into three groups: those with local disease that is cured by mastectomy; those with occult disseminated disease at presentation; and those with some residual local-regional disease after mastectomy, but without micrometastases.
It is this last group (perhaps 10% of the total) that could be helped by postmastectomy radiation therapy, Dr. Lichter believes, even given recent advances in systemic therapy.