Background: Using an enzyme immunoassay for epidermal growth factor receptor (EGFR), we investigated whether serum EGFR levels could be used as predictors of the development and extent of lung cancer.
Methods: The study included 106 lung cancer patients and 16 patients with nonmalignant thoracic disease. Serum samples were collected before clinical treatment.
Results: There was no difference between serum EGFR levels in patients with lung cancer (21.275 +/- 22.035 fm/ml) in comparison with those in nonmalignant-disease controls (22.630 +/- 7.330 fm/ml; P = 0.8083). However, lung cancer patients with lymph node metastasis (23.515 +/- 20.065 fm/ml) had significantly higher EGFR levels compared with those in patients without lymph node metastasis (16.390 +/- 10.970 fm/ml; P = 0.0228). The serum EGFR levels were similar in samples from lung cancer patients with various pathological subtypes. There was no difference in the prognosis between the lung cancer group with normal EGFR levels (<850 ng/ml) and the group with elevated EGFR levels (>850 ng/ml).
Conclusion: Serum EGFR levels may serve as a marker that can be used as an indicator of lymph node metastasis in lung cancer. However, there was no difference between levels in patients with lung cancer and those in nonmalignant-disease controls, indicating that the measurement of serum EGFR levels was of limited value in the detection of lung cancer.