Incidence of neoplasms in patients who develop sustained leukopenia during or after treatment with 6-mercaptopurine for inflammatory bowel disease.
OBJECTIVE
Studies to date have not confirmed an association between neoplasms and inflammatory bowel disease (IBD) treated with 6-mercaptopurine (6-MP). We have observed the occurrence of some neoplasms in IBD patients who developed sustained leukopenia as a result of treatment with 6-MP. As a result, we sought to compare the incidence of neoplasms in patients who developed sustained leukopenia after taking 6-MP compared with patients treated with 6-MP without sustained leukopenia.


METHODS
A database containing the medical records of more than 600 patients treated with 6-MP for IBD at 1 center between 1965 and 2002 was searched. The patients were divided into 2 groups. The study group consisted of patients who developed sustained leukopenia, defined as a white blood cell count of less than 4000 for 20 or more days. The control group patients matched those in the study group for age and sex. There were 3 matched controls for each patient in the study group.


RESULTS
Eighteen patients developed sustained leukopenia and, of these, 4 developed neoplasms (22%)-2 leukemias, 1 non-Hodgkin's lymphoma, and 1 breast cancer. Of the 54 patients in the control group, 4 developed neoplasms (7%) (P = .10). Post hoc analysis revealed a statistically significant difference in the number of hematologic malignancies in the group with sustained leukopenia (P = .014). There was no significant difference between the 2 groups for all confounding variables examined.


CONCLUSIONS
There was a trend toward a greater number of total malignancies in the sustained leukopenic patients. The data suggest that it is those patients who develop sustained leukopenia while taking 6-MP/azathioprine who are most at risk.
Disanti
William
W
Department of Gastroenterology, Lenox Hill Hospital, New York, New York 10021, USA.
Rajapakse
Ramona O
RO
Korelitz
Burton I
BI
Panagopoulos
Georgia
G
Bratcher
Jason
J
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D019992:Databases as Topic; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage / Q000009:adverse effects*; D015994:Incidence; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D007970:Leukopenia / Q000139:chemically induced*; D008297:Male; D015122:Mercaptopurine / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D009369:Neoplasms / Q000209:etiology*; D012189:Retrospective Studies
D007166:Immunosuppressive Agents; D015122:Mercaptopurine