A case of diffusely infiltrating rectal cancer with pulmonary lymphangitis carcinomatosa successfully treated with mFOLFOX6 chemotherapy as salvage

: We report a case of diffusely infiltrating rectal cancer with pulmonary lymphangitis carcinomatosa that responded to mFOLFOX6 chemotherapy and enabled survival for 19 months. A 68-year-old man was admitted to our hospital for a dry cough and dyspnea. Chest X-ray and CT examination revealed prominent pulmonary markings and abnormal infiltrating shadows. Interstitial pneumonia was suspected, and we started treatment with steroid medication, but this had no effect. A colonoscopy and barium enema revealed diffusely infiltrating rectal cancer. Abdominal CT and PET showed lymphangitis carcinomatosa of the lung, paraaortic lymph node swelling, and left hydronephrosis due to rectal cancer. The patient was diagnosed with stage IV rectal cancer. Thus, a curative operation was deemed impossible. Because of subileus, we performed a decompression loop colostomy in the transverse colon, and started treatment with mFOLFOX6 chemotherapy as salvage in spite of the patient's poor respiratory condition. Though the patient's tumor markers were very high (CEA 107 ng/mL, CA19-9 7,940 U/mL) prior to chemotherapy, they decreased dramatically (CEA 49.7 ng/mL, CA19-9 772 U/mL), and subjective symptoms (dry cough and dyspnea) also improved after 2 courses. After 3 courses of treatment the patient was discharged. After 7 courses, pulmonary markings and abnormal infiltrating shadows had disappeared on chest X-ray and CT. This condition was maintained for 19 months by ambulant chemotherapy without sacrificing high quality of life. Thus, mFOLFOX6 chemotherapy could be an effective salvage regimen in cases of diffusely infiltrating rectal cancer with pulmonary lymphangitis carcinomatosa.