[Procollagen-I, collagen telopeptide I, CEA, CA 15-3 as compared to bone scintigraphy in patients with breast cancer]

Abstract

The most common metastases of breast cancer (BC) are bone metastases. Serum pro-Iota collagen peptide (PICP) and I collagen telopeptide (ICTP) levels indicate the rate of bone collagen synthesis and bone resorption respectively and therefore indicate metastatic activity in the bone. We have studied the clinical importance of serum PICP and ICTP as well as CA 15-3 and CEA and compared them to bone scintigraphy findings indicating metastases from BC. Ninety seven women of mean age 58+/-8 years with BC were examined. The diagnosis of BC was histologically confirmed. Bone metastases were diagnosed in 68 of them by bone scans performed after the intravenous injection of 925 MBq of technetium-99m methylendiphosphonate, while 29 patients were free from bone metastases. We also examined 52 women of similar age, as controls. Serum PICP, ICTP, CA 15-3 and CEA were measured in both patients and controls. Serum levels of ICTP and CA 15-3 were significantly higher in patients with BC and bone metastases compared to patients without metastases (P<0.05), while PICP and CEA were only marginally higher. A statistically significant correlation was observed between the existence of bone metastases and ICTP serum levels (P<0.05). The sensitivity of PICP, ICTP, CEA and CA 15-3 was 28.1%, 48.6%, 78%, 42% respectively and their specificity was 83.9%, 94%, 65% and 86% respectively.

In conclusion: ICTP and CA 15-3 are the most reliable markers of those studied for the diagnosis of bone metastases in BC. PICP alone or combined with ICTP were not sensitive enough. CA 15-3 showed sensitivity 78% and specificity 86%. When combining CA 15-3, ICTP and CEA the sensitivity and specificity increased to 82% and 96% accordingly.