[Carcinoembryonic antigen (CEA) in patients with lung cancer: correlation with tumour extent and response to treatment (author's transl)].

Carcinoembryonic antigen (CEA) was determined at the time of diagnosis in 90 patients with lung cancer. CEA levels were elevated in 47 (52%). High CEA levels were often associated with the presence of metastases. Serial CEA determinations in 40 patients, before and after radiotherapy and chemotherapy, revealed that patients who responded to treatment had a decreased CEA level, whereas those with progressive tumour growth had increased ones. CEA assay may, therefore, be useful in detecting metastases and in helping to assess the effect of treatment in patients with lung cancer.