Small-cell lung cancer that newly developed as second primary cancer 13 years after last-line treatment for small-cell lung cancer

The patient was a 65-year-old man who was treated with concurrent chemoradiotherapy after being diagnosed with limited disease small-cell lung cancer 13 years previously; a complete response was achieved. After 13 years, he was diagnosed with prostate cancer. Chest computed tomography showed a mass in the middle lobe of the right lung, and small- cell lung cancer was diagnosed as a second primary cancer. He received concurrent chemoradiotherapy, but died 6 months after diagnosis. Patients who have achieved a complete response after treatment for small-cell lung cancer should be followed-up carefully in order to detect any possible second cancers.