Tumor type M2 pyruvate kinase expression in advanced breast cancer

Background: Recently, a high validity correlation of the tumor M2 pyruvate kinase (Tu M2-PK) isoenzyme in comparison to standard tumor markers has been demonstrated in solid tumors. We investigated this markers in 67 patients with advanced breast cancer (ABC) in comparison to healthy controls. Materials and Methods: Plasma Tu M2-PK was measured using an ELISA assay (ScheBo(R) Tech Giessen, Germany) while serum CA27.29 was determined using a chemiluminescent immunoassay (Bayer Diagnostics Tarrytown, USA). Results: In a ROC analysis, the art-off to discriminate patients from controls was established at 15 U/ml for Tu M2-PK (specificity 85%; positive predictive value 81%) and 30 U/ml for CA27.29 (specificity 91%; positive predictive value 92%). Median ABC baseline levels (ranges) in patients with ABC Sol Ttl M2-PK and CA27.29 were 12.8 U/ml (4.8-252495) and 130 U/ml (13.3-8130), respectively. Response assessment was done in 45 chemotherapy courses of 35 pts. In 13 out of 19 blocks (68.4%) with PD (progressive disease), an elevated level of Tu M2-PK at baseline ol in the follow-lip was found In 17 out of 20 block (85%) with SD (stable disease), the Tn M2-PK level was normal at baseline ol normalised within 4 week of treatment. All 6 patients with disease remission had a normal baseline Tn M2-PK level or the levels decreased promptly. Conclusion: Tu M2-PK gives additional information about ABC, indicating disease activity and sensitivity to chemotherapy while CA27.29 reflects tumor burden.