A case report of synchronous small cell lung cancer and gastric cancer successfully treated with carboplatin.

A 53-year-old man complained of anorexia and abdominal distention of one month's duration. The chest X-ray demonstrated a mass in the left lung with hilar and mediastinal adenopathy and a lytic lesion in the right fourth rib. A transbronchoscopic biopsy of the mass revealed oat cell carcinoma (WHO classification). The endoscopic evaluation also revealed a gastric lesion (IIc type). Biopsy of this lesion indicated signet ring cell gastric cancer. An abdominal CT scan demonstrated multiple liver metastases. Based on these findings, the patient was diagnosed as having synchronous lung and gastric primaries, with liver and bone metastasis from lung cancer. Carboplatin (CBDCA) was administered by intravenous drip infusion of 450 mg/m2. After a second treatment with CBDCA about 3 weeks later, the patient achieved a partial response at the primary site of lung cancer as well as at the liver and bone metastases. In addition, repeat endoscopy of the stomach demonstrated a complete regression. A biopsy specimen taken by gastroscopy was negative for cancer cells. Subsequent chemotherapy for small cell lung cancer was administered with cyclophosphamide, adriamycin, and vincristine, and to date there is no evidence of recurrence. Further studies on CBDCA treatment of small cell lung cancer and gastric cancer are needed to establish the efficacy of this drug against these two histologically different cancers.