Serum levels of C-erbB-2 (HER-2/neu) in patients with malignant and non-malignant diseases.
The diagnostic value of a new tumor marker, c-erbB-2, was studied in the sera of 50 controls, 112 patients with benign diseases and 534 patients with malignancies. Using 15 U/ml as the cutoff, no healthy subjects, patients with benign diseases (excluding liver cirrhosis) or patients with no evidence of disease (45 patients) had serum levels higher than this limit. Abnormal c-erbB-2 levels were found in 38.5% (10 of 26) of the patients with liver cirrhosis and in 26.7% (8 of 30) of those patients with primary liver cancer. No differences were found between the c-erbB-2 serum concentrations in liver cirrhosis or primary liver cancer, suggesting the possible catabolism of this antigen in the liver. Abnormal levels of this antigen were found in 20% (56 of 278) of the patients with breast carcinoma (locoregional 7%, metastases 41.5%), in 21% (6 of 28) of ovarian carcinomas (stage I-II 0%, stage III-IV 42.8%), in 21% (3 of 14) of the colorectal tumors (locoregional 0%, metastases 30%), and in 13.3% (11 of 83) of the patients with lung cancer (locoregional 11.5%, metastases 16%). C-erbB-2 sensitivity in other patients with advanced disease was: 25% (9 of 36) in prostatic cancer, 22% (2 of 9) in gastric cancer, and 11% (1 of 9) in vesical tumors. When patients with liver metastases were excluded abnormal c-erbB-2 serum levels were only found in breast, lung, prostatic and ovarian carcinomas. C-erbB-2 sensitivity in patients with lung cancer was related to tumor histology with significantly higher value in non-small cell lung cancer (mainly adenocarcinomas) than in patients with small cell lung cancer (p < 0.013). C-erbB-2 concentrations in patients with breast cancer were significantly higher in patients with recurrence (mainly bone and liver metastases) and in patients with progesterone receptor-negative (< 15 fmol/mg) tumors (p < 0.01). In conclusion, c-erbB-2 is not a specific tumor marker and abnormal serum levels may be found in patients with liver pathologies. Its sensitivity suggests its possible application as a tumor marker in breast, ovarian, lung (mainly adenocarcinomas) and prostatic tumors.