[A Study of Patients Who Underwent Breast-Conserving Surgery and Developed Cryptogenic Organizing Pneumonia(COP)]

Of the 210 patients who underwent breast-conserving surgery for breast cancer and received radiation therapy for 3 years from April 2012 to March 2015 at the Department of Therapeutic Radiology of our hospital, 6 were diagnosed with cryptogenic organizing pneumonia(COP)-like pneumonia and treated as reported. The mean age of the patients was 51years(40- 65 years), and the pathological subtypes were the luminal type(5 cases)and HER2 type(1case ), all of which were treated with radiation therapy for breast conservation. Postoperative systemic therapy included hormonal therapy with anastrozole in 2 cases, tamoxifen plus LH-RH agonist in 3 cases, and chemotherapy in 1case. The mean onset time of COP was 4.2 months after the completion of irradiation therapy, and all of the 5 patients who received endocrine therapy received it concurrently with radiation therapy. The major symptoms were fever(4 cases)and cough(6 cases). Chest radiography showed an infiltrative shadow consistent with pneumonia. Steroid therapy was effective in all cases while antibiotics were not. It was inferred that COP should be regarded as one of the complications of radiation therapy after breast-conserving surgery.