Background. As reported in previous studies, porphyria cutanea tarda (PCT) developed in several tamoxifene-treated
patients with breast cancer. We studied the group of patients with cancer having only tamoxifene therapy after the
initial surgery. We evaluated their clinical and laboratory results and compared them with the results of the group of
patients suffering also from breast tumor, but treated after the surgery with other systemic therapies , mostly with
Methods and Results. 20 patients were complexly studied, 10 of them with only tamoxifene therapy, and 10 without
it. Diagnosis of the breast tumor was histologically confirmed in all of them. With the use of laboratory methods we
examined their urinary excretion of diagnostically important porphyrins (uro- and coproporphyrin), then total blood
count, liver function tests (ALT and AST), blood sugar, cholesterin, serum iron and ferritin, and performed also urinanalysis
and detection of possible anti-HCV antibodies. The laboratory examination was repeated in the patient subgroup
after three months, urinary uro- and coproporphyrin excretion also in the the control group, for to have an
opportunity to follow the dynamics of laboratory changes. All the patients were examined during their regular laboratory
controls performed so as not to be bothered with repeated additional phlebotomies. We did not confirm in our
patients suffering from breast tumor the results of other autors, suggesting the connection between tamoxifene-therapy
and development of porphyria cutanea tarda.
Conclusions. Isolated cases of PCT can be induced through the effect of various hepatotoxic factors. However, the
influence of common porphyrinogenically acting noxious substances (alcohol, HCV virus or iron overload as a result
of the HFE gene mutations) were not found in our patients.
tamoxifene, porphyria cutanea tarda, PCT, estrogenic hormons, cytostatic drugs, breast carcinoma.