Clinical trial NCT06223698: Optimizing Extended Adjuvant Endocrine Therapy in Patients With Breast Cancer
Official title: Optimizing Extended Adjuvant Endocrine Therapy in Patients With Breast Cancer: a Registry-based Randomized Clinical Trial - SWE-Switch Breast Cancer Trial
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: PHASE3
Conditions: Breast Cancer
Keywords: breast cancer
adjuvant therapy
endocrine treatment
extended therapy
Lead sponsor: Region Örebro County
Sponsor class: OTHER
Collaborators: name: Mid-Sweden Regional Cancer Centre
name: Akademiska University Hospital, Uppsala, Sweden
First posted: 2024-01-25
Enrollment: 3832
Sex: FEMALE
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: Two separate cohorts will be randomized (two arms in each study cohort)
Primary purpose: TREATMENT

Brief summary: Based on the risk of late recurrence in breast cancer patients with luminal disease with high-risk for recurrence, extended adjuvant endocrine therapy beyond 5 years is recommended as a valid treatment option. In premenopausal women at diagnosis converted to postmenopausal after the first five years of tamoxifen, two treatment strategies for extended adjuvant endocrine therapy are available, namely continuing with tamoxifen or switching to aromatase inhibitors (AI). No randomized evidence does exist and both treatment strategies are used in clinical practice. In postmenopausal women with higher recurrence risk initially treated with AI for five years, extended adjuvant therapy with additional two years of AI has shown to be as effective as additional five years of AI. However, no randomized evidence on whether a switching strategy of five-year extended tamoxifen is better compared to two-year extended AI is available. Both treatment strategies are used in clinical practice.

The primary objective of this register-based randomized trial is to investigate the overall survival between patients treated with switching strategy for extended adjuvant endocrine therapy compared to continuing with the same treatment as the initial 5 years in two different clinical scenarios:

* In premenopausal women at diagnosis who converted to postmenopausal after 5 years of tamoxifen.
* In postmenopausal women at diagnosis.


Eligibility criteria: Inclusion Criteria:

Cohort 1 (premenopausal women at diagnosis converted to postmenopausal)

1. Women who were pre- or perimenopausal at diagnosis
2. Luminal breast cancer (defined as estrogen-receptor positive \>/=10%, HER2-negative disease).
3. Treated with tamoxifen for at least 80% of a 5-year period (+/- 6 months from treatment completion).
4. No clinical signs of metastasis after 5 years tamoxifen treatment.
5. cN+ breast cancer at diagnosis indicating the need for extended adjuvant endocrine therapy.
6. Postmenopausal status at study entry defined according to the National Comprehensive Cancer Network Guidelines.

Cohort 2 (postmenopausal women at breast cancer diagnosis)

1. Women who were postmenopausal at diagnosis.
2. Luminal breast cancer (defined as estrogen-receptor positive \>/=10%, HER2-negative disease).
3. Treated with AI for at least 80% of a 5-year period (+/- 6 months from treatment completion).
4. No clinical signs of metastasis after 5 years AI treatment.
5. cN+ breast cancer at diagnosis indicating the need for extended adjuvant endocrine therapy.

Exclusion Criteria:

Cohort 1

1. Prior invasive breast cancer diagnosis.
2. Other invasive malignancy within 5 years before or after breast cancer diagnosis
3. Non-luminal breast cancer (defined as estrogen-receptor \< 10%).
4. Patients who were unable to complete at least 80% of 5-year initial treatment with tamoxifen.
5. Uncertain menopausal status (unable to evaluate menopausal status according to aforementioned definitions).
6. Recurrent or metastatic breast cancer within or after 5-year initial treatment with tamoxifen (DCIS-only is allowed at any time before or after breast cancer diagnosis).

8) Unable to give informed consent in Swedish. Cohort 2

1. Prior invasive breast cancer diagnosis.
2. Other invasive malignancy within 5 years before or after breast cancer diagnosis; non-Luminal breast cancer (defined as estrogen-receptor \< 10%).
3. Patients who were unable to complete at least 80% of 5-year initial treatment with AI.
4. Recurrent or metastatic breast cancer within or after 5-year initial treatment with AI (DCIS-only is allowed at any time before or after breast cancer diagnosis).

6) No contraindication for tamoxifen therapy. 7) Unable to give informed consent in Swedish.

Primary outcomes:
measure: Overall survival
timeFrame: 120 months
Secondary outcomes:
measure: Invasive disease-free survival
timeFrame: 36 months; 60 months; 120 months
measure: Distant disease-free survival
timeFrame: 36 months; 60 months; 120 months
measure: Breast cancer-specific survival
timeFrame: 36 months; 60 months; 120 months
measure: Overall survival
timeFrame: 36 months; 60 months
measure: Frequency of selected grade 3/4 toxicities
timeFrame: 36 months; 60 months; 120 months
measure: Overall quality of life (EORTC QLQC30)
timeFrame: 24 months; 60 months
measure: Adherence to treatment strategies (medical possession ratio)
timeFrame: 36 months; 60 months; 120 months
measure: Duration of sick leave
timeFrame: 36 months; 60 months; 120 months
Other outcomes:
Locations:
city: Visby
country: Sweden
facility: Visby Hospital
state: Gotland
city: Eskilstuna
country: Sweden
facility: General Hospital of Eskilstuna
city: Falun
country: Sweden
facility: Falun County Hospital
city: Gävle
country: Sweden
facility: Gävle Hospital
city: Göteborg
country: Sweden
facility: Sahlgrenska University Hospital
city: Jönköping
country: Sweden
facility: Ryhov County Hospital
city: Kalmar
country: Sweden
facility: Kalmar Hospital
city: Lund
country: Sweden
facility: Lund University Hospital
city: Stockholm
country: Sweden
facility: Karolinska University Hospital
city: Stockholm
country: Sweden
facility: St Göran Capio Hospital
city: Umeå
country: Sweden
facility: University Hospital of Umeå
city: Uppsala
country: Sweden
facility: Akademiska University Hospital Uppsala
city: Västerås
country: Sweden
facility: Västerås General Hospital
city: Växjö
country: Sweden
facility: Växjö Hospital
city: Örebro
country: Sweden
facility: Örebro University Hospital
Study officials:
References: