Tamoxifen in breast cancer: symptom reporting

Clinical studies have traditionally identified treatment-specific side effects by comparison of voiced side effects in treatment and placebo arms of a study. Highly motivated women in a clinical trial may underreport drug-induced symptoms for medications which may be considered lifesaving. Affective symptoms during treatment of early breast cancer with tamoxifen (an estradiol receptor antagonist) were reported as infrequent by the manufacturer. However, reports suggest a higher rate of depression during general use. The objective of the present study was to examine the frequency of symptoms that might be side effects of tamoxifen and to relate them to the way the women attributed such symptoms. The exploratory study involved semistructured telephone interviews of 25 women who were taking tamoxifen. Textual analysis of the information was used to examine the symptoms described by the women. They were also asked whether any symptoms were related to the medication. The symptoms and their attribution were evaluated against a background of self-perceived stress. The principal finding was a pattern of ambivalence in attributing symptoms to the drug. Of all the symptomatic changes noted, the women only attributed 51% to tamoxifen. Flushes, fatigue, and depression were reported most frequently during treatment; flushes were readily attributed to tamoxifen but depression and fatigue were attributed to another factor by half of the symptomatic women. Women who reported moderate to high levels of life stress were less likely to attribute symptoms to drug therapy. The results suggest that women taking tamoxifen may not attribute known drug side effects to use of the medication.