THROMBOEMBOLIC ACCIDENTS IN POSTMENOPAUSA L PATIENTS TREATED BY TAMOXIFEN AS ADJUVANT TREATMENT - FREQUENCY, RISK-FACTORS AND PREVENTION

Tamoxifen is the anti-estrogen the most widely used in breast cancer. The duration of its prescription, as adjuvant treatment, tends to incr ease (5 years, and even more) and now it is used in chemoprevention. A slight increase of thromboembolic complications was noted in some stu dies. This article evaluates the frequency of thromboembolic accidents (TEA) in 441 postmenopausal patients treated by an association of con servative radiosurgery, tamoxifen +/- chemotherapy, for a breast carci noma TO, Tin < 4 cm. Nineteen patients (4.3%), all in remission, prese nted a TEA, between I and 44 months after the beginning of the tamoxif en treatment. We observed seven pulmonary embolisms (PE), II deep veno us thromboses (DVT) and an acute arterial ischemia. Two patients aged 74 and 80 years died, the others had a favourable evolution under anti coagulant treatment. Among these 19 patients, sh presented known risks factors (phlebitis, cardiovascular disorders) and ten had a <<favouri ng circumstance>> aggravating the risk of TEA (surgical operation, sev ere infection, fracture). Their median age was 65 years (61 for all th e 441 patients). We noted eight cases of breast lobular cancer (42%) a mong these 19 patients (11% for all the patients). Among postmenopausa l patients, the indication of tamoxifen must be evaluated according to the benefits expected in those with high risk factors of TEA (history of heart failure, obesity, spread varix, age > 65 years). In case of DVT and/or PE, this treatment seems contra-indicated. In case of <<fav ouring circumstances>>, a hypocoagulant or systematic anticoagulant tr eatment must be proposed. In case of combined chemotherapy, it is bett er to start tamoxifen at the end of the treatment. These simple prophy lactic measures should allow to reduce significantly the risk of TEA i n postmenopausal patients with adjuvant anti-estrogenotherapy