The experience of thyroid papillary carcinoma as secondary cancer during administration of gefitinib for lung cancer

Epidermal growth factor receptor （EGFR） tyrosine kinase inhibitors improve the prognosis of cancer patients and bring many treatment options. We often experience patients with secondary cancer during the treatment for primary cancer. A 76-year-old man, who taking gefitinib for lung cancer, visited our hospital complaining of hoarseness, and was diagnosed with thyroid papillary carcinoma. We planned total thyroidectomy and neck dissection. We stopped the administration of gefitinib 5 days before and after the operation because the mechanism of action of gefitinib was expected to delay wound healing. As a result, a delay in wound healing and progression of lung cancer did not occur. In the future, there will be many cases of double cancer or secondary cancer. Currently, there are many options for cancer treatment: surgery, chemotherapy, biotherapy, radiotherapy and their combinations. We must accumulate experience of therapies for multiple cancer and establish the risk and safety of combination therapy.