Background and aims: A relatively large number of patients with multiple myeloma have been reported to develop a secondary malignancy such as cancer of the breast, biliary system or bowel.
Methods: A retrospective study was perfomed in 734 patients with hematologic disease diagnosed at Nippon Medical School Hospital between May 1984 and September 1994 to determine the incidence of colorectal cancer in these patients based on a history review, colonoscopic findings, and surgical or autopsy data.
Results: Of the 734 patients, 14 (1.9%) had colorectal cancer; two of 11 patients (18.2%) had pure red cell aplasia; two of 25 patients (8%) had multiple myeloma; and three of 46 patients (6.5%) had aplastic anemia. Patients with pure red cell aplasia, multiple myeloma or aplastic anemia had colorectal cancer at a significantly higher rate compared to those with leukemia (P< 0.005, P< 0.02, P< 0.01, respectively).
Conclusions: It is possible that a relatively large number of patients with pure red cell aplasia, multiple myeloma or aplastic anemia will develop a colorectal cancer.