Fast neutrons in the treatment of locally advanced breast cancer

The clinical investigation of fast neutrons at Hammersmith Hospital included 17 patients who between them had 20 T4 breast cancers. The majority of these tumours were ulcerated and all were painful. Ten had recurred after multiple other therapies. Complete local regression was achieved in all but one (95%) and no tumour recurred. Symptoms were relieved in all cases. Median survival was 26 months. Three patients developed small areas of skin necrosis following trauma of previous radiation. All the neutron treated breasts became fibrosed, but this was painless. Neutron treatment needed only 12 attendances over 28 days, in contrast to the best results from photon therapy which required 6-7 weeks followed by implant of radioactive wire and/or surgical excision. One patient who had bilateral tumours received neutrons to the left breast and X-ray therapy (photons) to the right. The photon treated tumour did not completely regress and recurred. The neutron treated one completely regressed and did not recur. Neutrons were also more effective than tamoxifen which causes complete regression in only about 30% of cases. It is suggested that neutron therapy is indicated for locally advanced tumours which do not respond to hormones. Since metastases were a common cause of death, there remains a need for an effective adjuvant treatment, acceptable to elderly patients.