Endocrine Abstracts

Introduction: Chemotherapy, as a systemic therapy, is one of the most effective modalities for cancer treatment. However, the use of chemotherapeutic drugs in patients with breast cancer can lead to thyroid dysfunction. The aim of our work is to determine the influence of adjuvant chemotherapy on thyroid function in female patients with breast cancer after radical mastectomy and before radiotherapy.

Materials and methods: Our study was conducted on 40 Egyptian female patients(18–60) years of age who received adjuvant chemotherapy with 5-flourouracil, epirubicin and cyclophosphamide for breast cancer after mastectomy and before radiotherapy. Free T3, Free T4, TSH, anti-thyroglobulin antibody and thyroid peroxidase antibody were measured before treatment and after the 6th cycle (six months) of chemotherapy.

Results: On comparing the results of the studied group before and after chemotherapy, there were high significant difference in TSH value P = 0.005 being higher after chemotherapy (2.42 mU/l before chemotherapy vs. 2.87 mU/l after chemotherapy), significant difference in free T4 values P = 0.025 being lower after chemotherapy(1.32 ng/dl before chemotherapy vs. 1.23 ng/dl after chemotherapy), but there was no significant difference in free T3 value P = 0.051, Concerning both anti-thyroglobulin and anti-peroxidase there was no change in values before and after chemotherapy.

Conclusion: Receiving adjuvant chemotherapy in breast cancer patients was associated with significant elevation of TSH and decrease in fT4 levels which in spite of still being in the normal range, it may lead to overt hypothyroidism with longer duration of follow up.