CANCER RECURRENCES AND 2ND PRIMARY CANCERS AFTER USE OF ANTIHISTAMINES OR ANTIDEPRESSANTS

Objective: Reports in the scientific literature have described acceler ated tumor growth in association with antidepressant and antihistamine exposure in experimental rodent cancer models, This study was designe d to determine whether exposure to prescription antidepressants or ant ihistamines is associated with tumor growth in humans. Methods: Two ne sted case-control studies were conducted with a cohort of 1467 patient s with breast cancer, colon cancer, or melanoma diagnosed between 1988 and 1994. Eligible patients included 95 with a cancer recurrence and 78 with a second primary Lesion diagnosed during the follow-up period. Five control subjects were matched to each case patient according to cancer site, stage, and follow-up time, Conditional logistic regressio n was used to compare risk for tumor recurrence or occurrence of a sec ond primary tumor among patients using antidepressants or antihistamin es with risk among unexposed patients. Results: For a cohort of patien ts who were predominantly female (78%), with breast cancer (57%) and w ith a tumor in situ or with localized disease (79%), the average age w as 62 years at cancer diagnosis and average duration of follow-up peri od was 2.2 years, Use of antidepressants or antihistamines was unrelat ed to risk for tumor recurrence (odds ratio, 0.97; 95% confidence inte rval, 0.52 to 1.78) or second primary tumors (odds ratio, 0.94; 95% co nfidence interval, 0.50 to 1.77). Conclusion: Typical use of antidepre ssant or antihistamine drugs did not increase risk for recurrent or se cond primary tumors among patients with cancer.