Published in Cancer Detection and Prevention 1993; 17(1).

Serum type IV collagen and laminin fragments in patients with small cell lung cancer

T Nakano MD, M Takenaka MD, N Aihara MD, N Iwahashi MD, T Hada MD, K Higashino MD

3rd Dept of Internal Medicine, Hyogo College of Medicine, Hyogo, Japan

Small cell lung cancer (SCLC) is characterized by rapid proliferation and early metastatic dissemination. Tumor invasion of the underlying basement membrane (13M), penetration of and extravasation from blood vessels require type IV collagenase and proteinase capable of digesting laminin (I-N). Recently, proteinases capable of digesting the components of BM have been isolated from SCLC cells. It is conceivable that fragments of the BM components will appear in the body fluids when invasive tumors disrupt BIVI. We investigated whether circulating BM fragments could be valuable indicators of distant metastasis and clinically useful as a biomarkers in SCLC. The levels of LN P1 and type IV collagen fragment (7S collagen) in serum were elevated in 58.9% and 47.4 %, respectively, of SCLC patients. The levels of LN P1 and 7S collagen were related to therapeutic response. However, no certain correlation was established between the level of LN P1 and the clinical stage of SCLC, neither was there any correlation between the 7S collagen level and clinical stage. The level of neither fragment tend to correlate with the number of metastatic sites. We conclude that LN and type IV collagen fragments are useful biomarkers in SCLC, but that they do not help in assessing the occurrence of distant metastases.

Paper presented at the International Symposium on Cofactor Interactions and Cancer Prevention; Nice, France; March 17-19, 1993; in the section on Diagnostic Markers.