High performance liquid chromatographic determination of serum UV profiles of normal subjects and patients with breast cancer and benign fibrocystic changes.

High performance liquid chromatography (HPLC) was used to determine the UV profiles of serum samples taken postoperatively from 22 patients with histologically documented breast cancer, 8 patients with benign breast fibrocystic changes and 10 normal subjects. The analyses were performed on coded serum samples and after they were completed, the code was broken and the results correlated with the clinical data. Only one ml of serum was required for the HPLC analysis and identification. Detection limits for the nucleosides and bases were in the 10--20 pmol range and the injection volume of the deproteinated serum was 75 mul. The UV profiles of the normal subjects were very reproducible and similar to those of the patients with benign fibrocystic changes. The profiles of some of the cancer patients were distinctly different from the two other groups, 1-methylinosine and N2-methylguanosine, which were not detected in sera from normal subjects and patients with benign fibrocystic changes, were found in 45.5% and 22.7% of the cancer patients, respectively. Patients with the metastatic disease also showed elevated levels of guanosine and uridine. Only one false positive was found in the normal population. At present, it is not clear whether this indicates a subclinical manifestation of the disease and it must await further follow-up.