Hormone Replacement Therapy Monitoring

Introduction to FSH Monitoring

The National Comprehensive Cancer Network (NCCN) recommends FSH/LH levels monitoring in specific situations to ensure appropriate hormone therapy management, especially when monitoring menopausal status and when changing hormone therapy regimens 1
FSH monitoring is necessary during hormone replacement therapy to confirm menopausal status, assess ovarian function, and ensure treatment efficacy 1

FSH monitoring is recommended after switching from tamoxifen to an aromatase inhibitor (AI) 1
FSH monitoring is recommended if taken off ovarian function suppression (OFS) 1
FSH monitoring is recommended prior to the next dose of GnRH agonist, particularly in women under age 45 1
FSH monitoring is recommended if under 60 years and amenorrheic for ≤12 months prior to treatment with adjuvant endocrine therapy 1
FSH monitoring is recommended when amenorrheic after chemotherapy or after tamoxifen with or without ovarian function suppression 1
FSH monitoring is recommended if vaginal bleeding occurs while on AI therapy (contact physician immediately) 1

Menopausal status cannot be reliably determined while receiving hormone therapy 1
AIs can stimulate ovarian function in some women 1
Many patients incorrectly assume that menstrual cycles indicate fertility 2

The frequency of testing estradiol and FSH/LH levels should be individualized based on age, type of hormone therapy, presence of symptoms suggesting hormonal fluctuations, and changes in therapy regimen 1

Assuming menopausal status based on amenorrhea alone while on hormone therapy 1
Failing to monitor FSH when switching between different types of hormone therapy 1
Not recognizing that AIs can stimulate ovarian function in some women 1
Overlooking the need for FSH monitoring in women under 60 who have been amenorrheic for less than 12 months 1