trations in patients with advanced nasopharyngeal carcinoma. Thirty-two patients with nasopharyngeal cancer and 32 con- trol subjects were investigated.
Tumor Biol. DOI 10.1007/s13277-014-2708-0
RESEARCH ARTICLE
Diagnostic value of serum M30 and M65 in patients with nasopharyngeal carcinoma Fatma Sen & Ibrahim Yildiz & Hatice Odabas & Makbule Tambas & Leyla Kilic & Ahmet Karadeniz & Musa Altun & Meltem Ekenel & Murat Serilmez & Derya Duranyildiz & Sevil Bavbek & Mert Basaran
Received: 20 August 2014 / Accepted: 3 October 2014 # International Society of Oncology and BioMarkers (ISOBM) 2014
Abstract M30 and M65 are circulating fragments of cytokeratin 18 released during apoptotic cell death and regarded as markers of cell death in patients with various tumor types. Our aim was to investigate the clinical and prognostic significance of the serum M30 and M65 concentrations in patients with advanced nasopharyngeal carcinoma. Thirty-two patients with nasopharyngeal cancer and 32 control subjects were investigated. Serum samples were obtained on first admission before any treatment was initiated. Serum M30 and M65 concentrations were measured by quantitative enzyme-linked immunosorbent assay. Median serum M30 (181.5 vs. 45.5 U/L, p1000/mm3, and platelet count >100,000/mm3. Patients with a history of malignancies, diabetes mellitus, or uncontrolled infection were excluded. Progression-free survival (PFS) was defined as the time from diagnosis to the last follow-up or first evidence of relapse. The control group consisted of 32 healthy relatives of the NPC patients, 16 males and 16 females, ranging in age from 23 to 71 years (median=40), with no known diseases. Blood samples were collected from patients before any cancer therapy and from healthy controls into dry tubes and centrifuged within 30 min at 1000g for 10 min. Serum samples were stored at −80 °C until analysis. The study protocol was approved by the Local Ethics Committee of our facility, and written informed consent was obtained from each patients and control subjects. The procedures of the study followed were in accordance with the ethical standards of the committee on human experimentation
of the institution or in accord with the Helsinki Declaration of 1975 as revised in 1983. Measurement of M30 and M65 M30 and M65 concentrations were measured by the enzymelinked immunosorbent assay (ELISA) using commercially available M30-Apoptosense and M65-ELISA kits (Peviva AB, Sweden), respectively. All samples were analyzed simultaneously after being diluted 1:1 with standard A solution, with each assay including samples containing 0 U/L of M30 or M65 and dilutions of a synthetic peptide. Serum concentrations of M30 and M65 were determined using standard curves and expressed as unit per liter (U/L; 1U=1.24 pmol). The linear ranges for M30 and M65 were 0–1000 and 0– 2000 U/L, respectively. Statistical analysis Since the distribution of study parameters was non-normal, the non-parametric tests were used. Median M30 and M65 concentrations in the patient and control groups were compared using Mann–Whitney U test. The receiver operating characteristic (ROC) analysis was done for finding the cutoff value for both markers. The importance of serum M30 and M65 levels on PFS was evaluated by univariate analysis. Survival curves were calculated by the Kaplan–Meier method and compared using log–rank tests. Factors predictive of relapse were analyzed by both univariate analysis and multivariate analysis using a Cox proportional hazards model. Multivariate p values were used to characterize the independence of these factors. The relationship between survival time and each independent factor was quantified by calculating 95 % confidence intervals (CI). All p values were two-sided, with p values
