title: Is CA242 really a new tumour marker for pancreatic adenocarcinoma?
abstract: CA 242, a sialylated carbohydrate epitope situated on the same macromolecule as CA 50 has been proposed as a new tumour marker for pancreatic cancer (PC). The aims of the present study were: (1) to evaluate serum CA 242 versus CA 19-9 in PC patients, and (2) to assess whether these markers can predict tumour spread or patient survival. We studied 59 healthy controls, 27 PC patients, 12 chronic pancreatitis cases, 107 with extra-pancreatic gastrointestinal tumours, 30 with benign jaundice and 24 with benign extra-pancreatic gastrointestinal diseases. Mean CA 242 values were significantly higher in PC than in any other group; CA 19-9 showed a similar pattern. The best diagnostic efficacy (ROC curves analysis) in diagnosing PC was 86% for CA 242 and 84% for CA 19-9, using cut-off values of 60 and 80 U/ml, respectively. In PC, serum levels of both markers were unrelated to tumour spread or size; in PC patients with high levels of CA 242 or CA 19-9 survival was significantly shorter. CA 242 and CA 19-9 were correlated both when considering all the patients together (r = 0.962, p < 0.001) and PC alone (r = 0.880, p < 0.001). Given the very close relationship between CA 242 and CA 19-9, we tested for cross-reactivity between CA 242 antigen and CA 19-9 antibody: CA 242 antigen with CA 19-9 antibody produced a similar curve to CA 242 antigen and its corresponding antibody. In conclusion, CA 242 showed similar diagnostic values to CA 19-9 in assessing PC patients; both seem unrelated to tumour size or spread, but seem to predict survival. Their remarkably similar behaviour is due to cross-reactivity between CA 242 antigen and CA 19-9 antibody, so CA 242 cannot, in our opinion, be considered a new tumour marker for PC.
authors.affiliation: Institute of Laboratory Medicine, University of Padua, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Plebani
authors.forename: D
authors.initials: D
authors.lastname: Basso
authors.forename: F
authors.initials: F
authors.lastname: Navaglia
authors.forename: F
authors.initials: F
authors.lastname: D'Angeli
authors.forename: M P
authors.initials: MP
authors.lastname: Panozzo
authors.forename: G
authors.initials: G
authors.lastname: Del Giudice
authors.forename: M
authors.initials: M
authors.lastname: Battistel
authors.forename: T
authors.initials: T
authors.lastname: Meggiato
authors.forename: G
authors.initials: G
authors.lastname: Del Favero
mesh_terms: D000230:Adenocarcinoma / Q000097:blood*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D014408:Biomarkers, Tumor / Q000097:blood*; D018395:CA-19-9 Antigen / Q000097:blood; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000097:blood*; D014407:Tumor Cells, Cultured
chemical_list: D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; C074601:CA 242 antigen; D018395:CA-19-9 Antigen