Background: Components of the extracellular matrix play a fundamental role in the process of tumor invasion. The objective of this study was to evaluate the value of Type I collagen metabolites as tumor markers in patients with lung carcinoma.
Methods: In this study, the serum concentrations of the cross-linked carboxyterminal telopeptide of Type I collagen (ICTP) and the aminoterminal propeptide of Type I collagen (PINP) were measured in 59 consecutive patients with lung carcinoma. The blood concentrations of neuron-specific enolase (NSE), carcinoembryogenic antigen (CEA), sialyl Le-1 antigen (SLX), squamous cell carcinoma antigen (SCC), and D-dimer were also evaluated. Data obtained on 18 age-matched healthy subjects and 12 age-matched patients with benign lung disease were available for comparison.
Results: The serum concentrations of PINP were significantly higher in patients with lung carcinoma than in age-matched controls. Prechemotherapy values of PINP and ICTP were significantly increased in patients who did not respond to chemotherapy compared with those who did respond. PINP and ICTP were significantly correlated with clinical stage, extent of bone metastasis, survival time, and D-dimer. PINP was also significantly correlated with tumor size. ICTP was significantly correlated with CEA, SLX, SCC, and NSE. PINP also tended to correlate with these tumor-associated glycoproteins. PINP had a better receiver operating characteristic curve than ICTP. The specificity of PINP (79%) for the diagnosis of bone metastasis was superior to that of ICTP (58%).
Conclusions: The results of this study showed that, in addition to the important information that ICTP and PINP provide about the tumor cell-extracellular matrix interaction, they appear to be of great value as adjunct tools for the diagnosis of bone metastasis and as markers of the clinical response to therapy, clinical progression, and prognosis in lung carcinoma patients. However, more studies must be conducted to evaluate further the utility of these markers before their application in clinical practice.