Carcinoembryonic antigen (CEA) as a candidate prognostic marker of nonmucinous pneumonic adenocarcinoma (P-ADC) of the lung.

28 Background: Serum level of CEA as a prognostic marker in NSCLC is well known. In patients with non-mucinous P-ADC, there were some paradoxical cases with high CEA, in spite of improved symptom and chest X-ray after chemotherapy including first-generation EGFR-TKI. Methods: We retrospectively comfirmed serum level of CEA of five patients, including four patients with non-mucinous P-ADC and one patient with mucinous P-ADC, between 2001-2007, all Japanese female without smoking history, 66-78 years old (mean 73.6 y.o.). All of them revealed abnormal pneumonic shadow on chest X-ray, and were diagnosed by TBLB or cytology. These cases were all stage IIIB or IV, and were applied to chemotherapy including first-generation EGFR-TKI. We had measured serum CEA as possible from initial diagnosis and pre or post chemotherapy including first-generation EGFR-TKI to death. OS were between 25~66 months with four patients of non-mucinous P-ADC, and 9 month with one patient of mucinous P-ADC. Other tumor marker such as CYFRA and Pro GRP were all almost normal range. Results: CEA of three patients with non-mucinous P-ADC was elevated according to worsened symptom and X-ray, and were all highly maintained or increased in spite of improved symptom and X-ray after chemotherapy including first-generation EGFR-TKI. CEA of one patient with non-mucinous P-ADC was normal range in initial diagnosis, and no more measured. She has got symptom free and improved chest X-ray after chemotherapy. In one patient with mucinous P-ADC, serum CEA was normal range, so no longer measured. This patient was no effective for chemotherapy, and was dead 9 month after the initial diagnosis. Number of cases was quite few, so further examination is favorable. Furthermore, All cases were exaggerated finally, they might be resistant to first-generation EGFR-TKI. Conclusions: In three patients with non-mucinous P-ADC of the lung, serum CEA was paradoxically highly maintained or elevated in spite of improved symptom and chest X-ray after chemotherapy including first-generation EGFR-TKI. Therefore, serum CEA is a candidate for useful prognostic marker of non-mucimous P-ADC of the lung.