Goserelin

證據等級: L5

預測適應症: 3 個

Goserelin: From Hormone-Sensitive Cancers & Endometriosis to Amenorrhea

One-Sentence Summary

Goserelin (brand name Zoladex) is a GnRH receptor agonist with EMA/FDA-approved indications for hormone receptor-positive breast cancer, prostate cancer, endometriosis, and uterine fibroids, though it is not currently marketed in Canada. The TxGNN model predicts it may be effective for Amenorrhea (disease) — specifically as a pharmacological amenorrhea inducer — with 7 clinical trials and 19 publications currently supporting this direction. The mechanistic link is exceptionally direct: amenorrhea is goserelin’s primary downstream pharmacological effect, and the evidence base is mature.

Quick Overview

Item	Content
Original Indication	Not approved in Canada; globally EMA/FDA-approved for breast cancer, prostate cancer, endometriosis, and uterine fibroids
Predicted New Indication	Amenorrhea (disease)
TxGNN Prediction Score	99.99%
Evidence Level	L1
Canada Market Status	Not marketed
Number of DINs	0
Recommended Decision	Proceed with Guardrails

Why is This Prediction Reasonable?

Goserelin is a synthetic analogue of GnRH (Gonadotropin-Releasing Hormone). When administered continuously via subcutaneous depot injection, it initially stimulates GnRH receptors but rapidly causes receptor downregulation at the pituitary. This leads to profound suppression of LH and FSH secretion, which in turn reduces ovarian estrogen synthesis to near-castrate levels — directly inducing reversible pharmacological amenorrhea. This is not an indirect or speculative mechanism: amenorrhea is the intended pharmacodynamic endpoint of goserelin therapy.

The relationship between goserelin’s established indications and the predicted new use is unusually tight. In endometriosis and uterine fibroids, goserelin works precisely because it induces amenorrhea, allowing estrogen-dependent lesions to regress. In hormone receptor-positive breast cancer, the same ovarian suppression reduces the circulating estrogens that drive tumour growth. Chemotherapy-induced premature ovarian failure is prevented by co-administering goserelin to induce temporary amenorrhea and “shield” the ovaries. Across all these indications, amenorrhea is not a side effect — it is the mechanism.

Given this background, the TxGNN prediction that goserelin is effective for amenorrhea as a discrete indication is strongly biologically grounded. The model score of 99.99% reflects a well-established pharmacological truth rather than a novel inference. The clinical question is therefore less “is this plausible?” and more “in which specific patient populations and amenorrhea subtypes does formal evidence exist?”

Clinical Trial Evidence

Trial Number	Phase	Status	Enrollment	Key Findings
NCT00427245	Phase 3	Completed	400	OPTION trial: Goserelin vs no goserelin during chemotherapy for Stage I–III breast cancer; primary endpoint was prevention of early menopause (amenorrhea rate)
NCT00068601	Phase 3	Completed	257	LHRH agonist (goserelin) + chemotherapy vs chemotherapy alone; primary endpoint was ovarian failure (amenorrhea) after treatment in hormone receptor-negative early breast cancer
NCT02483767	Phase 3	Completed	98	Goserelin added to standard chemotherapy in premenopausal breast cancer; ovarian function recovery and amenorrhea rate were key secondary endpoints
NCT01218581	Phase 2/3	Completed	32	Head-to-head RCT comparing GnRH agonist vs aromatase inhibitor for uterine adenomyosis in fertility-preserving patients; amenorrhea induction was the primary therapeutic target
NCT02132390	Phase 3	Unknown	300	Adjuvant toremifene ± goserelin in premenopausal HR+ breast cancer; chemotherapy-induced amenorrhea was a stratification variable and secondary endpoint
NCT03475758	Phase 2	Unknown	100	Goserelin for ovarian protection during cyclophosphamide-containing chemotherapy; menstruation outcome (amenorrhea rates at 1 and 3 years) was the primary endpoint
NCT00488722	N/A	Unknown	N/A	Single-arm study of Zoladex + CEF chemotherapy as neoadjuvant therapy in premenopausal breast cancer; noted that Zoladex “can induce reversible amenorrhea” comparable to ovarian ablation

Literature Evidence

PMID	Year	Type	Journal	Key Findings
28472240	2017	Meta-analysis / RCT pooling	Annals of Oncology	OPTION trial results: GnRH agonist during chemotherapy significantly reduced premature ovarian insufficiency (amenorrhea-based endpoint) in early breast cancer
17159194	2007	RCT secondary analysis	J Clin Oncology	IBCSG Trial VIII: Compared amenorrhea and hot flash rates across chemotherapy, goserelin, and combination arms; goserelin arm showed highest sustained amenorrhea rates with better QOL profile
14679153	2003	RCT	J National Cancer Institute	IBCSG Trial VIII: Sequential CMF followed by goserelin vs either alone for premenopausal node-negative breast cancer; amenorrhea documented as major treatment-related outcome
12488406	2002	RCT	J Clin Oncology	ZEBRA study: Goserelin vs CMF in node-positive premenopausal breast cancer; goserelin produced consistent amenorrhea and survival outcomes comparable to chemotherapy
8513962	1993	RCT	Fertility and Sterility	GnRH agonist (goserelin) vs low-dose OCP for endometriosis-associated pelvic pain; goserelin-induced amenorrhea was central to its efficacy
25187267	2015	Cohort	Cancer Research and Treatment	Goserelin ovarian ablation improved survival in Stage II/III HR+ breast cancer patients without chemotherapy-induced amenorrhea, underscoring amenorrhea as a therapeutic mechanism
12353820	2002	Review	Breast Cancer Res Treatment	Comprehensive review of LHRH agonists in early breast cancer; confirms goserelin induces “reversible ovarian ablation” (amenorrhea) and is the most extensively studied agent in this class
1533675	1992	Review	J Royal Army Medical Corps	Therapeutic induction of amenorrhea overview; identifies goserelin as “extremely effective” at amenorrhea induction with reversible effect — one of the earliest dedicated amenorrhea-indication reviews
10730389	1999	Case series	Akusherstvo i Ginekologiia	GnRH agonist (Zoladex) used to induce amenorrhea for controlling severe uterine hemorrhage in adolescents with aplastic/hypoplastic anaemia; bleeding stopped within 2–4 days
17006733	2007	Case report	Int Urology and Nephrology	Vesicouterine fistula treated via cystoscopic fulguration plus hormonal amenorrhea with goserelin; authors advocate this approach as a primary minimally invasive option

Canada Market Information

Goserelin is not currently approved or marketed in Canada (0 DINs). It holds EMA and FDA approval for hormone receptor-positive breast cancer, prostate cancer, endometriosis, and uterine fibroids in international markets. No Canadian product licence table is available.

Cytotoxicity

Goserelin is classified as an antineoplastic hormonal agent (GnRH agonist), with established use in breast cancer and prostate cancer.

Item	Content
Cytotoxicity Classification	Hormonal / Endocrine therapy (GnRH agonist) — NOT a conventional cytotoxic drug
Myelosuppression Risk	Low — GnRH agonists do not cause bone marrow suppression
Emetogenicity Classification	Minimal — subcutaneous depot injection; emesis not a recognized class effect
Monitoring Items	Bone mineral density (with long-term use >6 months), serum estradiol/testosterone for suppression confirmation, hot flashes and mood assessment
Handling Protection	Standard subcutaneous injection handling; no cytotoxic spill precautions required (non-cytotoxic mechanism)

Safety Considerations

Safety data from the Canadian regulatory file is unavailable (goserelin is not marketed in Canada). Please refer to the package insert of the originator product (Zoladex, AstraZeneca) for complete warnings, contraindications, and precautions. Key clinical considerations known from the literature include:

Tumour flare: Initial GnRH agonist administration transiently raises testosterone/estrogen before suppression; antiandrogen/antiestrogen co-administration may be required in the first 2–4 weeks
Bone density loss: Prolonged use (>6 months) is associated with decreased bone mineral density; consider add-back therapy or DEXA monitoring
Hot flashes and menopausal symptoms: Common class effect during ovarian suppression
Contraindication in pregnancy: Goserelin can cause fetal harm and is contraindicated in pregnant women

Conclusion and Next Steps

Decision: Proceed with Guardrails

Rationale: The pharmacological mechanism linking goserelin to amenorrhea is not a predictive inference — it is the drug’s primary mode of action. Multiple completed Phase 3 RCTs with large sample sizes (NCT00427245 n=400; NCT00068601 n=257) directly evaluate goserelin-induced amenorrhea as a primary or key secondary endpoint, placing this at Evidence Level L1. The OPTION trial meta-analysis (PMID 28472240) further consolidates the evidence base.

To proceed, the following is needed:

Canada market entry pathway: Identify whether a New Drug Submission (NDS) or Abbreviated NDS pathway applies, given the drug is not currently DIN-listed
Canadian prescribing information: Obtain the Health Canada-approved monograph (if any prior submission exists) or rely on the PMDA/EMA/FDA-approved label as the primary safety reference
Targeted indication scoping: Clarify the specific amenorrhea subtype intended (e.g., therapeutic amenorrhea for endometriosis, ovarian protection during chemotherapy, or military/operational amenorrhea as in PMID 1533675) — each may require a distinct regulatory pathway
Bone density risk management plan: Protocol for DEXA monitoring and add-back HRT for any amenorrhea indication exceeding 6 months of therapy
Mechanism of action documentation: Retrieve full MOA data from DrugBank API (DG002) to complete the drug profile for regulatory dossiers
Disclaimer

This content is for research purposes only and does not constitute medical advice. Clinical validation is required before any clinical application.