Peritoneal relapse from lung adenocarcinoma after a response to EGFR-TKI.

kinase inhibitors (EGFR-TKIs) for EGFR-mutated elderly non-small cell lung cancer (NSCLC) patients has been reported (1,2). It is supposed that EGFR-TKIs are increasingly prescribed for them. In NSCLC patients, metastases to meningeal as well as peritoneal space are rare (3,4). However, carcinomatous meningitis, which attracts attention as a recurrence site of the patients who received EGFR-TKIs), is recently a devastating event occurring in NSCLC patients (5). For them, the treatment options currently available are very limited, and the prognosis of them remains poor (3,4). Usefulness of EGFR-TKIs for peritoneal carcinomatosis in two chemo-naive NSCLC patients has recently been reported (6,7), but antemortem diagnosis of carcinomatous peritonitis in NSCLC patients is very difficult (4). We experienced three cases with peritoneal relapse from lung adenocarcinoma after a response to EGFR-TKI. Table 1 showed clinical features of the three lung cancer patients with peritoneal recurrence. They were an 83 yearold woman and a 77 year-old men, and a 72 year-old woman. All of them were non-smokers, and diagnosed as having lung adenocarcinoma pathologically, and they had a point mutation in exon 21 (L858R), respectively. At the time of initial diagnosis, these two women had carcinomatous pleuritis. Gefitinib or erlotinib was prescribed as first line chemotherapy in each patient. All of them responded to the therapy, and progressive free survival was 31, 9, and 8 months, respectively. After these response periods, they complained distension of the abdomen. Abdominal CT scan detected ascites, but there found no other recurrent site than peritoneum. Cytological examination of ascites, lung adenocarcinoma was confirmed. Two patients had isolated peritoneal relapse, and one had peritoneal and meningeal relapse (8). They had supportive care only because of their poor performance status.