POEMS/S0230: Goserelin for Ovarian Protection During Adjuvant Chemotherapy in Premenopausal Hormone-Receptor–Negative Breast Cancer

Primary endpoint (ovarian failure at 2 years): 8% vs 22% — OR 0.30 (95% CI 0.09–0.97; two-sided P=0.04) Key secondary (pregnancy within 5 years): 21% vs 11% — OR 2.45 (95% CI 1.09–5.51; P=0.03) Key secondary (4-year DFS): 89% vs 78% — HR 0.49 (95% CI 0.24–0.97; P=0.04) Safety signal: Grade ≥2 hormonal toxic effects more common with goserelin (48% vs 24%; P<0.001)

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Clinical Bottom Line

POEMS/S0230 demonstrated that adding the GnRH agonist goserelin to standard cyclophosphamide-containing chemotherapy significantly reduced the rate of premature ovarian failure in premenopausal women with hormone-receptor–negative early breast cancer. Goserelin-treated patients were also significantly more likely to become pregnant after treatment, and the trial showed favorable disease-free survival and overall survival signals in the goserelin group — a finding that provides reassurance that ovarian protection does not compromise oncologic outcomes in this population.

This trial was one of the pivotal studies supporting the now-standard practice of offering GnRH agonist–mediated ovarian protection to premenopausal women undergoing gonadotoxic chemotherapy. As of 2026, ASCO, NCCN, and international guidelines recommend discussing GnRH agonist coadministration for fertility preservation with all premenopausal patients receiving chemotherapy, regardless of hormone-receptor status. POEMS was particularly important because it enrolled exclusively hormone-receptor–negative patients, removing the confounding question of whether GnRH agonists might independently affect breast cancer outcomes through endocrine manipulation.

The key practical consideration is that goserelin adds hormonal side effects — hot flashes, mood changes, and irregular menses — which were significantly more frequent at grade 2 or higher. However, high-grade toxicity rates were low and comparable between arms, and no new safety concerns emerged. The trial closed early due to funding loss and enrolled fewer patients than planned, which limits statistical power for some endpoints, particularly subgroup analyses and survival outcomes.

Trial Overview

Study Design

• Trial name and registration: POEMS/S0230, NCT00068601
• Design: Phase 3, randomized, open-label, controlled, final analysis
• Randomization: 1:1 ratio, stratified by age (<40 years vs 40–49 years) and chemotherapy regimen (3–4 cycles vs 6–8 cycles; anthracycline-based vs nonanthracycline-based)
• Setting: Operable stage I to IIIA breast cancer, adjuvant or neoadjuvant setting
• Enrollment period: February 2004 to May 2011 (14 sites from CALGB, ECOG, IBCSG, and SWOG)
• Funding: National Cancer Institute at the National Institutes of Health and AstraZeneca, the Australia and New Zealand Breast Cancer Trials Group, and the Breast Cancer Institute of Australia

The study closed early owing to loss of funding for study-drug distribution. The original target enrollment was 416 eligible patients; 257 were randomized.

Mechanism of Action

Goserelin is a synthetic GnRH agonist that, after an initial stimulatory phase, causes sustained suppression of pituitary gonadotropin secretion, leading to a marked reduction in ovarian estradiol production. During chemotherapy, this pharmacologic suppression is hypothesized to render the ovaries quiescent and less vulnerable to the gonadotoxic effects of alkylating agents such as cyclophosphamide [2].

Patient Population

• Key eligibility: Premenopausal women aged 18–49 years with operable stage I to IIIA ER-negative and PR-negative breast cancer planned for cyclophosphamide-containing adjuvant or neoadjuvant chemotherapy; no estrogen, antiestrogen, SERM, aromatase inhibitor, or hormonal contraceptive use within 1 month of enrollment
• Key exclusions: Interest in future fertility was not an eligibility requirement (i.e., patients were not required to desire future pregnancy)
• Biomarker selection: ER-negative and PR-negative (defined per treating institution's standard)
• Sample size flow: 257 randomized (131 chemotherapy alone; 126 chemotherapy + goserelin) → 233 eligible (120 chemotherapy alone; 113 chemotherapy + goserelin; 24 ineligible) → 218 evaluable (113 chemotherapy alone; 105 chemotherapy + goserelin; 15 unable to be evaluated) → 135 with complete 2-year primary endpoint data (69 chemotherapy alone; 66 chemotherapy + goserelin). Number screened was not reported in this publication.

Baseline Characteristics

Treatment Protocol

Control Arm: Chemotherapy Alone (n=131 randomized; n=113 evaluable; safety population n=111)

Standard adjuvant or neoadjuvant cyclophosphamide-containing chemotherapy without goserelin. - Dose and schedule: Choice of standard cyclophosphamide-containing chemotherapy regimen was left to the discretion of the investigator - Treatment duration: Not reported in this publication - Median treatment duration: Not reported in this publication - Median relative dose intensity: Not reported in this publication

Experimental Arm: Chemotherapy Plus Goserelin (n=126 randomized; n=105 evaluable; safety population n=103)

Standard adjuvant or neoadjuvant cyclophosphamide-containing chemotherapy plus goserelin (GnRH agonist). - Dose and schedule: Goserelin 3.6 mg administered subcutaneously every 4 weeks, beginning 1 week before the initial chemotherapy dose and continued to within 2 weeks before or after the final chemotherapy dose. Chemotherapy regimen at investigator discretion. - Treatment duration: Not reported in this publication - Median treatment duration: Not reported in this publication - Median relative dose intensity: Not reported in this publication

Efficacy Outcomes

Primary Endpoint: Ovarian Failure at 2 Years

Definition: Amenorrhea for the preceding 6 months and follicle-stimulating hormone (FSH) levels in the postmenopausal range at 2 years. Patients who became pregnant were considered not to have had ovarian failure. Patients who underwent hysterectomy or bilateral oophorectomy were categorized as unable to be evaluated. Assessment method: Menstrual status assessment and FSH level measurement at 2 years (assessment window within 6 months before or after the 2-year time point) Analysis population: All eligible patients who could be evaluated and who had complete 2-year data (N=135: 69 chemotherapy alone, 66 chemotherapy + goserelin) Statistical method: Conditional logistic regression, stratified according to age and type of chemotherapy regimen Median follow-up: 4.1 years (among patients still alive) Data cutoff: January 22, 2014

Chemotherapy alone: 22% (15 of 69 patients) Chemotherapy plus goserelin: 8% (5 of 66 patients) Comparison: OR 0.30 (95% CI, 0.09 to 0.97; one-sided P=0.02, two-sided P=0.04)

The prespecified one-sided alpha of 0.025 was met (one-sided P=0.02).

Sensitivity analyses were consistent with the main finding: - Deaths counted as ovarian failure: OR 0.25 (95% CI, 0.11 to 0.60; P=0.002) - Deaths and hysterectomy/oophorectomy counted as ovarian failure: OR 0.29 (95% CI, 0.16 to 0.75; P=0.007) - Amenorrhea or postmenopausal FSH at year 2: OR 0.29 (95% CI, 0.12 to 0.70; P=0.006) - Amenorrhea or postmenopausal FSH at year 1 or 2: OR 0.43 (95% CI, 0.22 to 0.85; P=0.01)

Univariate (unstratified) analysis: OR 0.30 (95% CI, 0.10 to 0.87; one-sided P=0.01, two-sided P=0.03) Multivariate analysis (adjusting for stratification factors plus cancer stage): OR 0.36 (95% CI, 0.11 to 1.14; one-sided P=0.04, two-sided P=0.08)

Key Secondary Endpoints

Pregnancy Within 5 Years (evaluable population, N=218)

Definition: At least one pregnancy, assessed annually over 5 years Analysis population: All 218 eligible patients who could be evaluated

• Chemotherapy alone: 11% (12 of 113 patients)
• Chemotherapy plus goserelin: 21% (22 of 105 patients)
• Comparison: OR 2.45 (95% CI, 1.09 to 5.51; P=0.03)

Among these pregnancies: - Attempted pregnancy: 18 (16%) chemotherapy alone vs 25 (24%) chemotherapy + goserelin (OR 1.78; 95% CI, 0.85 to 3.72; P=0.12) - ≥1 delivery: 8 (7%) chemotherapy alone vs 16 (15%) chemotherapy + goserelin (OR 2.51; P=0.05) - Delivery or ongoing pregnancy: 10 (9%) chemotherapy alone vs 19 (18%) chemotherapy + goserelin (OR 2.45; P=0.04) - Babies born: 12 in chemotherapy-alone group vs 18 in goserelin group - Ongoing pregnancies: 3 chemotherapy alone vs 5 goserelin - Miscarriages: 5 chemotherapy alone vs 4 goserelin - Elective terminations: 3 chemotherapy alone vs 2 goserelin

Ovarian Dysfunction at Year 1 (N=153 with available data)

Definition: Amenorrhea for the preceding 3 months and FSH, estradiol, or inhibin B levels in the postmenopausal range at year 1 Analysis population: Patients with both menstrual-status data and at least two available laboratory values at year 1

• Chemotherapy alone: 37% (28 of 75 patients)
• Chemotherapy plus goserelin: 23% (18 of 78 patients)
• Comparison: OR 0.64 (95% CI, 0.30 to 1.37; P=0.25)
• Whether this endpoint was formally tested in the statistical hierarchy was not reported in this publication. The difference was not statistically significant.

Ovarian Dysfunction at Year 2 (N=130 with available data)

Definition: Amenorrhea for the preceding 3 months and FSH, estradiol, or inhibin B levels in the postmenopausal range at year 2 Analysis population: Patients with both menstrual-status data and at least two available laboratory values at year 2

• Chemotherapy alone: 33% (22 of 67 patients)
• Chemotherapy plus goserelin: 14% (9 of 63 patients)
• Comparison: OR 0.35 (95% CI, 0.13 to 0.93; P=0.03)

Disease-Free Survival (evaluable population, N=218)

Definition: Events included breast-cancer recurrence and deaths due to any cause but not contralateral breast or nonbreast primary cancers Analysis population: All 218 eligible patients who could be evaluated

• Chemotherapy alone: 4-year Kaplan-Meier estimate 78% — 24 events
• Chemotherapy plus goserelin: 4-year Kaplan-Meier estimate 89% — 12 events
• Comparison: Adjusted HR 0.49 (95% CI, 0.24 to 0.97; P=0.04)

Overall Survival (evaluable population, N=218)

Definition: Events included deaths due to any cause Analysis population: All 218 eligible patients who could be evaluated

• Chemotherapy alone: 4-year Kaplan-Meier estimate 82% — 17 deaths
• Chemotherapy plus goserelin: 4-year Kaplan-Meier estimate 92% — 8 deaths
• Comparison: Adjusted HR 0.43 (95% CI, 0.18 to 1.00; P=0.05)

Exploratory Endpoints

Disease-Free Survival (all 257 randomized patients)

• Comparison: HR 0.64 (95% CI, 0.35 to 1.17; P=0.15)
• Among all randomized patients, the trend toward a higher rate of disease-free survival with goserelin was not significant.

Overall Survival (all 257 randomized patients)

• Comparison: HR 0.45 (95% CI, 0.21 to 0.97; P=0.04)
• In this exploratory analysis of the full randomized population, the rate of overall survival was significantly higher in the goserelin group.

Safety

Safety Population

• Chemotherapy alone: n=111
• Chemotherapy plus goserelin: n=103

Only adverse events related to hormonal effects and serious adverse events that occurred during chemotherapy with or without goserelin were routinely assessed, according to CTCAE v3.0. Standard chemotherapy-related toxicities (e.g., myelosuppression, nausea) were not captured in this reporting framework.

Safety Summary

Since fewer than 4 standard summary safety metrics were available, a summary table cannot be constructed. The following data were reported:

• Grade ≥3 toxic effects: 5% (chemotherapy alone) vs 7% (chemotherapy + goserelin) — P=0.89
• Grade ≥2 toxic effects: 24% (chemotherapy alone) vs 48% (chemotherapy + goserelin) — P<0.001

The following standard metrics were not reported in this publication: any TEAE rate, serious AE rate, treatment-related AE rate, treatment-related deaths, discontinuation due to AE, dose reduction rate, and dose interruption rate.

The significantly higher rate of grade ≥2 toxicity in the goserelin group reflects the expected hormonal side effects of GnRH agonist therapy (hot flashes, mood changes, irregular menses) rather than a concerning safety signal.

Grade 3 and Grade 4 Adverse Events

Grade 3 and grade 4 events were reported separately in this publication.

No grade 4 toxic effects occurred in the chemotherapy-alone group. One grade 4 thromboembolism occurred in the goserelin group. Of the 111 patients evaluable for adverse events in the chemotherapy-alone group, 6 had grade 3 toxic effects; of the 103 in the goserelin group, 6 had grade 3 and 1 had grade 4 toxic effects.

Deaths

• Chemotherapy alone: 17 deaths (among 218 evaluable patients; 113 in this arm)
• Chemotherapy plus goserelin: 8 deaths (among 218 evaluable patients; 105 in this arm)
• Treatment-related deaths were not separately reported in this publication.

Subgroup Analyses

No subgroup analyses were reported in this publication.

Key Comparator Trials

Comparator Table

Cross-trial comparisons are limited by differences in patient populations, trial designs, and endpoints. These data are presented for context, not for direct statistical comparison.

Contextual Notes

POEMS/S0230 is one of several randomized trials that evaluated GnRH agonist coadministration during chemotherapy for ovarian protection. The PROMISE-GIM6 trial [4] randomized a broader population (including HR-positive patients) to chemotherapy with or without triptorelin (a different GnRH agonist) and similarly demonstrated a significant reduction in premature ovarian failure. A key difference is that POEMS enrolled only HR-negative patients, providing cleaner evidence that the ovarian-protective benefit is independent of any endocrine treatment effect on the cancer itself.

The OPTION trial [5] evaluated goserelin during chemotherapy in a mixed HR-status population and also supported the ovarian-protective effect. Taken together, these trials formed the evidence base that led to guideline recommendations for GnRH agonist coadministration during chemotherapy for premenopausal women interested in fertility preservation — or simply in preservation of ovarian function.

A unique and notable finding of POEMS was the favorable DFS and OS signals in the goserelin group, which were unexpected for a trial designed to assess ovarian function. While these survival results should be interpreted cautiously given the small sample size and multiple comparisons, they provided important reassurance that GnRH agonist coadministration does not compromise oncologic outcomes and may even be associated with a benefit — a finding that has been supported by meta-analyses.

Grey Zones and Unanswered Questions

• The trial enrolled only HR-negative patients. While this was a strength for isolating the ovarian-protective effect from any endocrine anti-cancer effect, the results cannot be directly applied to HR-positive patients, who represent the majority of premenopausal breast cancer diagnoses and for whom the interpretation of GnRH agonist benefit is confounded by the potential therapeutic endocrine effect. Separate trial data (PROMISE-GIM6, OPTION) address this population.

• The trial closed early and was underpowered for its original design. Only 257 of the planned 416 patients were randomized, and the primary endpoint analysis was limited to 135 patients (62% of evaluable patients) with complete 2-year data. While sensitivity analyses were consistent with the main finding, the small sample size limits precision, as reflected in the wide confidence intervals around all effect estimates.

• The DFS and OS benefits are hypothesis-generating. The favorable DFS (HR 0.49) and OS (HR 0.43) signals in the evaluable population are striking but were based on few events (36 DFS events, 25 deaths). In the full randomized population, DFS was not significant (HR 0.64; P=0.15). The biological mechanism by which ovarian suppression during chemotherapy could improve survival in HR-negative breast cancer is unclear and requires further investigation.

• Long-term ovarian function beyond 2 years was not assessed as a primary endpoint. Whether goserelin's ovarian-protective effect persists long-term (>5 years) or whether late ovarian failure occurs at higher rates after initial recovery is not answered by this trial. The 2-year assessment window captures early recovery but not the full trajectory of ovarian aging after gonadotoxic chemotherapy.

• Patients older than 49 and those receiving non-cyclophosphamide regimens were excluded. The generalizability to women receiving cyclophosphamide-free regimens (increasingly common in HER2-positive disease) or to women at the upper boundary of reproductive age is uncertain.

• Race and ethnicity data were incomplete. Race was unknown for 42% and 33% of patients in the two arms, and ethnicity was unknown for 47% and 37%, limiting the assessment of outcomes across demographic subgroups.

Clinical Implications

Rationale and Clinical Context

Chemotherapy-induced premature ovarian failure is a major long-term consequence of adjuvant treatment for premenopausal breast cancer patients, affecting both quality of life and reproductive potential. Cyclophosphamide, an alkylating agent used in many standard breast cancer regimens, is particularly gonadotoxic. POEMS was designed to test whether temporary ovarian suppression with a GnRH agonist during chemotherapy could protect the ovaries from this damage.

Before POEMS and similar trials, the standard of care for fertility preservation consisted primarily of embryo or oocyte cryopreservation prior to chemotherapy — interventions that require time, cost, and access to reproductive medicine services. GnRH agonist coadministration offered a simpler, more accessible approach that could be implemented concurrently with chemotherapy without delaying treatment.

Monitoring and Long-Term Follow-Up

Given the 4.1-year median follow-up, ongoing monitoring of ovarian function, fertility outcomes, and disease recurrence remains important. Key monitoring considerations: - Menstrual status and FSH levels should be assessed periodically after chemotherapy completion to document ovarian recovery - Reproductive counseling should be offered to all patients of reproductive age, regardless of whether goserelin was administered - Disease surveillance per standard adjuvant breast cancer guidelines, recognizing that the favorable DFS/OS signals require confirmation with longer follow-up

Unanswered Questions

The two most practice-relevant open questions are: (1) whether the unexpected DFS and OS improvements with goserelin represent a true biologic effect or a consequence of small sample size and statistical chance, and (2) whether GnRH agonist ovarian protection provides meaningful benefit with modern, potentially less gonadotoxic chemotherapy regimens that have emerged since this trial's enrollment period.

Regulatory and Guideline Status

Regulatory

• FDA: Goserelin (Zoladex) is FDA-approved for palliative treatment of advanced breast cancer in pre- and perimenopausal women. The specific indication of ovarian protection during chemotherapy is not a separately approved indication, but use for this purpose is supported by guideline recommendations and is considered standard of care.
• EMA: Similar approval profile. Ovarian protection use is supported by clinical guidelines.

⚠️ Regulatory status verified as of March 2026. Confirm current approval status and labeled indications before clinical use at FDA.gov.

Guidelines

• NCCN: Recommends discussion of GnRH agonist coadministration during chemotherapy for ovarian function preservation in premenopausal patients; included in the Adolescent and Young Adult (AYA) Oncology and Breast Cancer guidelines [3].
• ASCO: 2018 fertility preservation guideline recommends that GnRH agonists be offered to patients interested in ovarian function preservation during gonadotoxic chemotherapy, with a note that this does not replace cryopreservation for patients who desire maximal fertility preservation.
• ESMO/St. Gallen: Supports GnRH agonist use during chemotherapy for ovarian protection in premenopausal patients.

Companion Diagnostics

ER-negative and PR-negative status must be confirmed by local testing per institutional standards. No specific companion diagnostic test is required for goserelin administration.

About the Author

Andrew Stevenson is the founder and systems architect of kill-cancer.com, a clinical intelligence platform delivering structured, source-traced oncology trial analysis to practicing clinicians. He holds 17 Google technical certifications in data systems, automation, and applied AI — the engineering foundation behind the extraction and verification pipeline that produces every article on this platform. Every number traces directly to its source publication. Zero calculation. Zero editorializing. Zero hallucination.

Five siblings lost to cancer built the urgency. The engineering builds the trust.

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Disclaimer

This article is intended for healthcare professionals only. It is not medical advice and should not be used as a substitute for professional clinical judgment. Treatment decisions should be made in consultation with qualified healthcare providers based on individual patient circumstances.

All trial data presented in this article are sourced directly from the published clinical trial report and its supplementary materials. Numbers are reproduced exactly as reported; no calculations, derivations, or estimates have been performed.

Trial results are presented as reported in the source publication. Updated data, label changes, or guideline revisions published after the source article may alter clinical applicability.

Comparator trial data presented in Section 8 are sourced from their respective published reports and are provided for contextual purposes only. Cross-trial comparisons have inherent limitations and should not be interpreted as direct statistical comparisons.

References

1. Moore HCF, Unger JM, Phillips K-A, et al. Goserelin for Ovarian Protection during Breast-Cancer Adjuvant Chemotherapy. N Engl J Med. 2015;372(10):923-932. doi:10.1056/NEJMoa1413204
2. Zoladex (goserelin acetate implant) prescribing information. U.S. Food and Drug Administration. Accessed March 2026.
3. NCCN Clinical Practice Guidelines in Oncology: Breast Cancer. Version 1.2026. Accessed March 2026.
4. Lambertini M, Boni L, Michelotti A, et al. Ovarian Suppression With Triptorelin During Adjuvant Breast Cancer Chemotherapy and Long-term Ovarian Function, Pregnancies, and Disease-Free Survival: A Randomized Clinical Trial. JAMA. 2015;314(24):2632-2640. doi:10.1001/jama.2015.17291
5. Leonard RCF, Adamson DJA, Bertelli G, et al. GnRH agonist for protection against ovarian toxicity during chemotherapy for early breast cancer: the Anglo Celtic Group OPTION trial. Ann Oncol. 2017;28(8):1811-1816. doi:10.1093/annonc/mdx184