Is serum beta 2-microglobulin a tumor marker in gastrointestinal cancer?

Serial determinations of serum beta 2-microglobulin (beta 2m) and carcinoembryogenic antigen (CEA) were performed in 314 patients with histologically confirmed gastrointestinal cancer. The data were correlated with a set of clinical parameters. Pre-operative serum beta 2m levels did not discriminate different classes of tumor extension nor different stages of resectability of tumors in contrast to CEA. During post-operative surveillance the correlation of the time courses of serum beta 2m and CEA with the clinical course of malignant disease was studied in a selected group of 165 patients with resected primary carcinoma of the gastrointestinal tract. During the follow-up 74/165 patients showed disease progression or recurrence. In the beta 2m follow-up 66% false negative indications (49/74) of malignant disease were observed, whereas in the CEA follow-up it was 5% (4/74). The ratio of correct positive/false positive indications was 25/10 in the beta 2m follow-up and 70/10 in the CEA follow-up. The data indicate that the formation of serum beta 2m is not directly tumor associated in gastrointestinal cancer.