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NCT00553410 · CITED IN SOURCE DOCUMENTS

Letrozole in Preventing Cancer in Postmenopausal Women Who Have Received 4-6 Years of Hormone Therapy for Hormone Receptor-Positive, Lymph Node-Positive, Early-Stage Breast Cancer

An NCI or FDA source cites this study. A citation does not establish that it applies to an individual diagnosis.

Phase
PHASE3
Status at capture
COMPLETED
Registry last update
2026-09-01

RATIONALE: Estrogen can cause the growth of breast cancer cells. Letrozole may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known which regimen of letrozole is more effective in postmenopausal women who have received hormone therapy for early-stage breast cancer. PURPOSE: This randomized phase III trial is comparing two different regimens of letrozole in preventing cancer in postmenopausal women who have received 4-6 years of hormone therapy for hormone receptor-positive, lymph node-positive, early-stage breast cancer.

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What did the study report?

Outcomes, safety and baseline populations are separate source sections. Quality-of-life measures appear under their original outcome titles.

flow

Participant flow

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baseline

Baseline characteristics

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outcome · POSTED

Disease-free Survival (DFS)

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outcome · POSTED

Overall Survival

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outcome · POSTED

Distant Recurrence-free Interval (DRFI)

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outcome · POSTED

Breast Cancer-free Interval

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adverse events

Adverse events

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more info

Limitations, agreements, and source contact

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Who could take part
eligibility Criteria
DISEASE CHARACTERISTICS: * Confirmed diagnosis of prior operable, noninflammatory breast cancer meeting the following criteria: * Steroid hormone receptor-positive tumors (estrogen receptor and/or progesterone receptor), determined by immunohistochemistry, after primary surgery and before commencement of prior endocrine therapy * Prior local treatment including surgery with or without radiotherapy for primary breast cancer with no known clinical residual loco-regional disease * Following primary surgery, eligible patients must have had evidence of lymph node involvement either in the axillary or internal mammary nodes, but not supraclavicular nodes * Clinically disease-free * Must have completed 4-6 years of prior adjuvant selective estrogen receptor modulators (SERMs), aromatase inhibitors (AIs), or a sequential combination of both * When calculating 4-6 years, neoadjuvant endocrine therapy should not be included * No evidence of recurrent disease or distant metastatic disease * No prior bilateral breast cancer PATIENT CHARACTERISTICS: * Female * Must be postmenopausal by any of the following criteria: * Patients of any age who have had a bilateral oophorectomy (including radiation castration AND amenorrheic for \> 3 months) * Patients 56 years old or older with any evidence of ovarian function must have biochemical evidence of definite postmenopausal status (defined as estradiol, luteinizing hormone \[LH\], and follicle-stimulating hormone \[FSH\] in the postmenopausal range) * Patients 55 years old or younger must have biochemical evidence of definite postmenopausal status (defined as estradiol, LH, and FSH in the postmenopausal range) * Patients who have received prior luteinizing-hormone releasing-hormone (LHRH) analogues within the last year are eligible if they have definite evidence of postmenopausal status as defined above * Clinically adequate hepatic function * No bone fracture due to osteoporosis at any time during the 4-6 years of prior therapy * No prior or current malignancy except adequately treated basal cell or squamous cell carcinoma of the skin, in situ carcinoma of the cervix or bladder, or contra- or ipsilateral in situ breast carcinoma * No other nonmalignant systemic diseases (cardiovascular, renal, lung, etc.) that would prevent prolonged follow-up * No psychiatric, addictive, or any other disorder that compromises compliance with protocol requirements PRIOR CONCURRENT THERAPY: * See Disease Characteristics * More than 12 months since prior and no other concurrent endocrine SERM/AI therapy * Any type of prior adjuvant therapy allowed including, but not limited to, any of the following: * Neoadjuvant chemotherapy * Neoadjuvant endocrine therapy * Adjuvant chemotherapy * Trastuzumab (Herceptin®) * Ovarian ablation * Gonadotropin releasing hormone analogues * Lapatinib ditosylate * No concurrent hormone-replacement therapy, bisphosphonates (except for treatment of bone loss), or any other investigational agent
healthy Volunteers
false
maximum Age
120 Years
minimum Age
18 Years
sex
FEMALE
std Ages
  1. ADULT
  2. OLDER_ADULT
Treatment arms and interventions
arm Groups
  1. description
    Continuous letrozole: 5 years continuously (2.5 mg Letrozole daily)
    intervention Names
    1. Drug: Letrozole
    label
    Continuous letrozole
    type
    ACTIVE_COMPARATOR
  2. description
    Intermittent letrozole: 48 months over 5 yrs: 4 x 9 months (9 mo followed by 3 mo treatment-free interval in yrs 1-4, -\> 36 mo) plus 1 x 12 mo in yr 5 -\> 48 months
    intervention Names
    1. Drug: Letrozole
    label
    Intermittent letrozole
    type
    EXPERIMENTAL
interventions
  1. arm Group Labels
    1. Continuous letrozole
    description
    Film-coated tablet, oral use, 2.5 mg Letrozole daily for 5 years continuously
    name
    Letrozole
    type
    DRUG
  2. arm Group Labels
    1. Intermittent letrozole
    description
    Film-coated tablet, oral use, 2.5 mg daily, 48 months over 5 yrs: 4 x 9 months (9 mo followed by 3 mo treatment-free interval in yrs 1-4, -\> 36 mo) plus 1 x 12 mo in yr 5 -\> 48 months
    name
    Letrozole
    type
    DRUG
Study design
allocation
RANDOMIZED
intervention Model
PARALLEL
masking Info
masking
NONE
primary Purpose
PREVENTION
Enrollment
count
4884
type
ACTUAL
Registered outcome plans (not posted results)
primary Outcomes
  1. description
    Duration of time from randomization to the first indication of the following events: invasive recurrence at local (including recurrence restricted to the breast after breast conserving treatment), regional or distant sites; a new invasive cancer in the contralateral breast; any second (non-breast) invasive malignancy; or a death without prior cancer event. Appearance of DCIS or LCIS either in the ipsilateral or in the contralateral breast was not be considered as an event for DFS. In the absence of an event, DFS was censored at the date of last follow-up visit.
    measure
    Disease-free Survival (DFS)
    time Frame
    5-year estimates, reported at a median follow-up of 60 months
secondary Outcomes
  1. description
    Duration of time from randomization to death from any cause, or was censored at the date last known alive. (Note, for patients who withdrew consent or were lost to follow-up but follow-up for survival was possible through hospital or registry records, OS was censored at the date last known alive rather than date of last follow-up/withdrawn consent).
    measure
    Overall Survival
    time Frame
    5-year estimates, reported at a median follow-up of 60 months
  2. description
    Duration of time from randomization to the first indication of invasive breast recurrence at a distant site. In the absence of an event, DRFI was censored at the date of last follow-up visit or date or death without distant recurrence.\* \*This endpoint replaced DDFS, which was specified in the protocol
    measure
    Distant Recurrence-free Interval (DRFI)
    time Frame
    5-year estimates, reported at a median follow-up of 60 months
  3. description
    Duration of time from randomization to the first indication of the following events: invasive breast recurrence at local, regional or distant sites; a new invasive cancer in the contralateral breast (second non-breast malignancies are ignored). In the absence of an event, BCFI was censored at the date of last follow-up visit or date of death without prior breast cancer event.
    measure
    Breast Cancer-free Interval
    time Frame
    5-year estimates, reported at a median follow-up of 60 months
Full study description
brief Summary
RATIONALE: Estrogen can cause the growth of breast cancer cells. Letrozole may fight breast cancer by lowering the amount of estrogen the body makes. It is not yet known which regimen of letrozole is more effective in postmenopausal women who have received hormone therapy for early-stage breast cancer. PURPOSE: This randomized phase III trial is comparing two different regimens of letrozole in preventing cancer in postmenopausal women who have received 4-6 years of hormone therapy for hormone receptor-positive, lymph node-positive, early-stage breast cancer.
detailed Description
OBJECTIVES: Primary * Compare the disease-free survival (DFS) of postmenopausal women treated with continuous letrozole for 5 years vs intermittent letrozole over a 5-year period. Secondary * Compare overall survival of patients treated with these two regimens. * Compare distant DFS of these patients. * Compare breast cancer-free interval of these patients. * Compare sites of first DFS failure in these patients. * Compare second (nonbreast) malignancies in these patients. * Compare deaths without prior cancer events in these patients. * Compare adverse events resulting from these two regimens. OUTLINE: This is a multicenter study. Patients are stratified according to treatment center and type of prior endocrine therapy (selective estrogen receptor modulators \[SERMs\] alone vs aromatase inhibitors \[AIs\] alone vs both SERMs and AIs each for at least 1 month). Patients are randomized to 1 of 2 treatment arms. * Arm I: Patients receive oral letrozole daily for 5 years. * Arm II: Patients receive oral letrozole daily for the first 9 months of years 1 through 4, followed by 12 months in year 5. After completion of study therapy, patients are followed annually.
Source references
references
  1. citation
    Guerini-Rocco E, Gray KP, Fumagalli C, Reforgiato MR, Leone I, Rafaniello Raviele P, Munzone E, Kammler R, Neven P, Hitre E, Jerusalem G, Simoncini E, Gombos A, Deleu I, Karlsson P, Aebi S, Chirgwin J, Di Lauro V, Thompson A, Graas MP, Barber M, Fontaine C, Loibl S, Gavila J, Kuroi K, Muller B, O'Reilly S, Di Leo A, Goldhirsch A, Viale G, Barberis M, Regan MM, Colleoni M. Genomic Aberrations and Late Recurrence in Postmenopausal Women with Hormone Receptor-positive Early Breast Cancer: Results from the SOLE Trial. Clin Cancer Res. 2021 Jan 15;27(2):504-512. doi: 10.1158/1078-0432.CCR-20-0126. Epub 2020 Oct 20.
    pmid
    33082214
    type
    DERIVED
  2. citation
    Colleoni M, Luo W, Karlsson P, Chirgwin J, Aebi S, Jerusalem G, Neven P, Hitre E, Graas MP, Simoncini E, Kamby C, Thompson A, Loibl S, Gavila J, Kuroi K, Marth C, Muller B, O'Reilly S, Di Lauro V, Gombos A, Ruhstaller T, Burstein H, Ribi K, Bernhard J, Viale G, Maibach R, Rabaglio-Poretti M, Gelber RD, Coates AS, Di Leo A, Regan MM, Goldhirsch A; SOLE Investigators. Extended adjuvant intermittent letrozole versus continuous letrozole in postmenopausal women with breast cancer (SOLE): a multicentre, open-label, randomised, phase 3 trial. Lancet Oncol. 2018 Jan;19(1):127-138. doi: 10.1016/S1470-2045(17)30715-5. Epub 2017 Nov 17.
    pmid
    29158011
    type
    DERIVED
Source notices and limitations
    Discovery and provenance
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        stically significant differences in adverse events between the arms.</li></ul></div></li><li>A phase III trial conducted by the IBCSG (<a href="/clinicaltrials/NCT00553410">SOLE</a> [NCT00553410]) included 4,851 receptor-positive postmenopausal women who had completed 5 years of adjuvant therapy with an AI, a selective estrogen r
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        fferences in adverse events between the arms.</li></ul></div></li><li>A phase III trial conducted by the IBCSG (<a href="/clinicaltrials/NCT00553410">SOLE</a> [NCT00553410]) included 4,851 receptor-positive postmenopausal women who had completed 5 years of adjuvant therapy with an AI, a selective estrogen receptor (ER) modulator,
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      source title
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      source update dates
      1. context
        Updated: April 25, 2025
        datetime
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        display
        April 25, 2025

    Preserved source evidence · Not medical advice