Evaluation of Hypothyroidism Incidence After Breast Cancer Supraclavicular Irradiation

A Prospective Multicentric Evaluation of the Rate of Incidence of Hypothyroidism After Supraclavicular Irradiation for Breast Cancer

Prospective, multicentric, comparative, non randomised, in current care.

Primary objective:

• To evaluate the incidence of hypothyroidism in breast cancer patients treated by radiotherapy including the supra-clavicular area over a period of 5 years (60 months).

Secondary objectives :

• To calculate the dose of irradiation received by thyroid gland during the treatment.
• To compare the rate of incidence of hypothyroidism in women who received a supra-clavicular irradiation (group 1)and in those who did not (group 2).
• To estimate and compare the rate of incidence of chronic thyroid lesions in the 2 groups.
• To look for predictive factors of hypothyroidism de novo in group 1 women particularly regarding the dose-volume parameters.
• To propose recommendations for the thyroid follow-up after supra-clavicular irradiation.

Prospective, multicentric, comparative, non randomised, in current care study

2 patient groups, non randomised, according to the necessity or not to perform a supra-clavicular irradiation:

• Group 1 : patients receiving a supra-clavicular irradiation
• Group 2 : patients not receiving a supra-clavicular irradiation.

Schedule

Projected inclusion duration of 18 months (duration to possibly adapt in order to obtain the number of required patients)

Intermediate study of the results in 30 months

Duration of follow-up of 60 months

Inclusion Criteria:

• Women older than 18
• Non metastatic breast cancer, histologically proved, whatever T and N stages and receptors status.
• Breast cancer treated by surgery (either initial treatment then biotherapies and/or neoadjuvant chemotherapy, either secondarily after biotherapies and/or neoadjuvant chemotherapy, either without chemotherapy and/or biotherapies)
• Breast cancer requiring an adjuvant radiotherapy
• Treatment by radiotherapy made in participating centers
• Information of patient and signature of the informed consent.

Exclusion Criteria:

• Pre-existent dysthyroidism revealed before radiotherapy or at inclusion checkup (THS lower or superior to the standard of the laboratory, whatever the rate of free T4)
• History of thyroid surgery
• Bilateral breast cancer
• History of cervical and/or supra-clavicular radiotherapy
• Lack of social security insurance
• Subjects deprived of free behavior or under administrative control