A new tumor biomarker, serum protein peak at 3,144 m/z, in patients with node-positive breast cancer

PURPOSE To explore the association between the 3,144 m/z protein peak and the clinicopathological features and prognosis in breast cancer. METHODS Using SELDI-TOF MS, we analyzed serum protein peak at 3,144 m/z in 283 patients with node-positive breast cancer, its relationship with clinicopathological features and their prognosis evaluating value of survival. RESULTS 3,144 m/z positive rate was higher in elderly patients (42.8 % in ≥50-year-old vs. 31.2 % in <50, P = 0.04). However, no correlation was observed between 3,144 m/z and other clinicopathological features (body mass index, menstrual status, family history, TNM, molecular subtypes, vascular invasion, neural invasion, p53 and CA15-3). However, the positive rate of 3,144 m/z was higher than that of CA15-3 (35.5 vs. 11.4 %, McNemar χ (2) test, p < 0.001). 3,144 m/z-negative patients (n = 177) had a better 3-year overall survival (OS) than 3,144 m/z-positive patients (n = 106) (89.8 vs. 81.2 %, P = 0.045). Younger patients (P = 0.016), postmenopausal status (P = 0.019), small tumor (P < 0.001), less positive nodes (P < 0.001), early stage (P < 0.001), favorable molecular subtype (P = 0.007), normal CA15-3 (P = 0.003) and neoadjuvant chemotherapy (P = 0.001) predicted better survival. Cox analysis showed that T3-4 (95 % CI 1.419-8.057, P = 0.006), lymph node metastasis (95 % CI 1.242-3.632, P = 0.006) and p53 mutation (95 % CI 1.088-6.378, P = 0.032) were independent adverse prognostic factors. But childbirth ≥2 (95 % CI 0.163-0.986, P = 0.046), adjuvant chemotherapy (95 % CI 0.062-0.921, P = 0.038) and adjuvant radiotherapy (95 % CI 0.148-0.928, P = 0.034) were the independent factors in reducing risk of death in breast cancer patients. Combination testing of 3,144 m/z and CA15-3 will improve the prognosis value of 3-year survival (P = 0.011); patients with CA153-/3144- were characterized by the longest survival (89.8 %) and the CA153+/3144+ patients by the shortest. CONCLUSIONS Serum protein peak at 3,144 m/z is a new biomarker for breast cancer diagnosis and prognosis and showed a higher positive rate than serum CA15-3. Combining 3,144 m/z and CA15-3 testing may improve prognosis of longer survival in breast cancer patients.