Deslorelin after excision of rat mammary tumours: does an implant reduce recurrence vs no implant? — MAYBE (weak evidence)

STAMP: MAYBE (weak evidence): No eligible record exists for this shelf, and this pack is honestly empty (no cards). PubMed searches run at drafting (Nov 10, 2026) combining deslorelin with rats and mammary tumour/tumor, recurrence, fibroadenoma and prevention — and broader GnRH-agonist implant searches in rats — found NO study, of any design, in which rats received a deslorelin implant after excision of a mammary tumour and were compared with no implant (or any control) for tumour recurrence. The exact-comparison searches returned zero records. Near-misses, documented here and deliberately not carded: (1) Jekl 2017 (PMID: 28781034), a narrative review of evidence-based rodent medicine, lists both 'use of deslorelin acetate in rodents' and 'prevention of mammary gland tumors in rats' among its topics — but it is a review, its abstract reports no study, no recurrence outcome and no figures, and prevention of first tumours is not the post-excision recurrence question asked here; it cannot carry a claim for this shelf. (2) Schoemaker 2018 (PMID: 29655478), a review of GnRH agonist implants in exotic companion animals, notes implants have proven effective for contraception in rats among other species — a fertility claim, not a mammary-recurrence claim. (3) Grosset 2012 (PMID: 23277700) is the primary pet-rat deslorelin record the reviews rest on: 4.7 mg implants in 3 experimental females (none conceived during 4 months after implantation) plus 38 client-owned pet rats (6 males, 32 females, mean age 14 months) recruited to record side effects (local reaction, transient weight gain in the first 2 weeks, behavioural changes) — a contraception/safety pilot with no mammary tumour excision, no recurrence follow-up and no control group for recurrence. (4) The remaining deslorelin-in-rats records are in males or other species/questions (e.g. PMID: 31158733, testicular suppression in adult male rats; PMID: 35588370, behaviour in female southern giant pouched rats, in which 6 months of deslorelin did not alter vaginal patency) and say nothing about mammary recurrence. Design class (c): randomisation is not established, because no eligible record exists at all. Tier C is not engaged: tumour recurrence is the outcome, and no mortality, fetal-loss or survival-primary benefit claim is made or carded. One-home cross-point: shelf #960 (deslorelin for egg laying in cockatiels) is a different species and a different question and shares no record with this shelf. Until a post-excision study — even a controlled case series with a no-implant comparison — is published, implanting deslorelin after rat mammary tumour excision to prevent recurrence rests on extrapolation from its contraceptive/hormonal effects, not on recurrence evidence. Drafted Nov 10, 2026 (VetMed build, topic #944); all figures from the abstracts fetched and verified at drafting.