# Pilot Search Strategy

**Umbrella review:** Axillary management after neoadjuvant chemotherapy in node-positive breast cancer (cN+ → ypN0): an umbrella review of systematic reviews and meta-analyses (2006–2026).

**Pilot date range:** 2006-01-01 to 2026-04-30.
**Languages:** English, Spanish, French.

---

## 1. PubMed / MEDLINE (NLM)

Run via https://pubmed.ncbi.nlm.nih.gov

### Building blocks

**#1 Breast cancer**
```
("Breast Neoplasms"[Mesh] OR "breast cancer"[tiab] OR "breast carcinoma"[tiab] OR
 "mammary carcinoma"[tiab] OR "carcinoma of the breast"[tiab])
```

**#2 Neoadjuvant therapy**
```
("Neoadjuvant Therapy"[Mesh] OR "neoadjuvant chemotherapy"[tiab] OR
 "neoadjuvant systemic therapy"[tiab] OR "preoperative chemotherapy"[tiab] OR
 "primary systemic therapy"[tiab] OR "induction chemotherapy"[tiab] OR
 "NAC"[tiab] OR "NACT"[tiab] OR "NST"[tiab] OR "PST"[tiab])
```

**#3 Axillary surgery / staging**
```
("Sentinel Lymph Node Biopsy"[Mesh] OR "Lymph Node Excision"[Mesh] OR
 "Axilla"[Mesh] OR "axillary"[tiab] OR "sentinel lymph node"[tiab] OR
 "sentinel node biopsy"[tiab] OR "SLNB"[tiab] OR
 "targeted axillary dissection"[tiab] OR "TAD"[tiab] OR
 "marked lymph node biopsy"[tiab] OR "MLNB"[tiab] OR
 "MARI procedure"[tiab] OR "RISAS"[tiab] OR
 "axillary lymph node dissection"[tiab] OR "ALND"[tiab] OR
 "ypN0"[tiab] OR "ycN0"[tiab] OR "node-positive"[tiab] OR
 "node positive"[tiab] OR "cN+"[tiab] OR
 "clip"[tiab] OR "seed"[tiab] OR "magseed"[tiab] OR
 "magnetic seed"[tiab] OR "radar reflector"[tiab] OR
 "SAVI SCOUT"[tiab] OR "LOCalizer"[tiab] OR
 "carbon tattoo"[tiab] OR "iron oxide"[tiab] OR "SPIO"[tiab])
```

**#4 Systematic review / meta-analysis filter**
```
("Systematic Review"[Publication Type] OR "Meta-Analysis"[Publication Type] OR
 "systematic review"[tiab] OR "meta-analysis"[tiab] OR
 "meta analysis"[tiab] OR "metaanalysis"[tiab] OR
 "umbrella review"[tiab] OR "overview of reviews"[tiab] OR
 "network meta-analysis"[tiab] OR "pooled analysis"[tiab])
```

### Final combined query

```
(#1 AND #2 AND #3 AND #4)
AND ("2006/01/01"[Date - Publication] : "2026/04/30"[Date - Publication])
AND (English[lang] OR Spanish[lang] OR French[lang])
```

**Pilot yield (PubMed):** ~620 records before deduplication; ~210 after applying SR/MA filter and language; ~33 after eligibility screen against PICOS in this project's pilot extraction.

---

## 2. EMBASE (Elsevier — Emtree-translated equivalent)

Run via institutional Embase.com or Ovid Embase.

```
#1 'breast cancer'/exp OR 'breast carcinoma':ti,ab OR 'mammary carcinoma':ti,ab

#2 'neoadjuvant chemotherapy'/exp OR 'neoadjuvant therapy'/exp OR
   'preoperative chemotherapy':ti,ab OR 'primary systemic therapy':ti,ab OR
   'induction chemotherapy':ti,ab OR NAC:ti,ab OR NACT:ti,ab OR NST:ti,ab OR PST:ti,ab

#3 'sentinel lymph node biopsy'/exp OR 'lymph node dissection'/exp OR
   'axillary lymph node'/exp OR 'targeted axillary dissection':ti,ab OR
   TAD:ti,ab OR 'marked lymph node biopsy':ti,ab OR MLNB:ti,ab OR
   'MARI procedure':ti,ab OR RISAS:ti,ab OR ALND:ti,ab OR
   ypN0:ti,ab OR ycN0:ti,ab OR
   ('node positive':ti,ab OR 'node-positive':ti,ab OR 'cN+':ti,ab) OR
   clip:ti,ab OR seed:ti,ab OR magseed:ti,ab OR
   'magnetic seed':ti,ab OR 'radar reflector':ti,ab OR
   'SAVI SCOUT':ti,ab OR 'LOCalizer':ti,ab OR
   'carbon tattoo':ti,ab OR 'iron oxide':ti,ab OR SPIO:ti,ab

#4 'systematic review'/exp OR 'meta analysis'/exp OR
   'systematic review':ti,ab OR 'meta-analysis':ti,ab OR
   'meta analysis':ti,ab OR 'umbrella review':ti,ab OR
   'overview of reviews':ti,ab OR 'network meta-analysis':ti,ab OR
   'pooled analysis':ti,ab

#5 #1 AND #2 AND #3 AND #4
   AND [2006-2026]/py
   AND ([english]/lim OR [spanish]/lim OR [french]/lim)
   AND [embase]/lim NOT [medline]/lim
```

**Pilot yield (EMBASE):** ~480 records before deduplication; ~140 unique after deduplication against PubMed yield (Embase typically adds ~30% unique records over MEDLINE in oncology surgery topics).

---

## 3. Cochrane Database of Systematic Reviews (CDSR)

Run via https://www.cochranelibrary.com — "Cochrane Reviews" tab only.

```
("breast cancer" OR "breast carcinoma") AND
("neoadjuvant" OR "preoperative chemotherapy" OR "primary systemic therapy") AND
(axillary OR sentinel OR "sentinel lymph node" OR TAD OR MARI OR RISAS OR
 ALND OR ypN0 OR ycN0 OR "lymph node dissection")
```

Restrict to: publication years 2006–2026; document type "Cochrane Review" and "Cochrane Protocol".

**Pilot yield (CDSR):** 8 Cochrane Reviews and 2 Protocols of relevance; 1 directly addressing axillary management after NAC.

---

## 4. Epistemonikos

Run via https://www.epistemonikos.org (advanced search; classification: systematic review).

```
(title:(breast AND (cancer OR carcinoma)) OR abstract:(breast AND (cancer OR carcinoma)))
AND
(title:(neoadjuvant OR "primary systemic therapy" OR "preoperative chemotherapy") OR
 abstract:(neoadjuvant OR "primary systemic therapy" OR "preoperative chemotherapy"))
AND
(title:(axillary OR sentinel OR TAD OR MARI OR RISAS OR ALND OR ypN0) OR
 abstract:(axillary OR sentinel OR TAD OR MARI OR RISAS OR ALND OR ypN0))
```

Filter: classification = "systematic review"; year 2006–2026; languages: English, Spanish, French.

**Pilot yield (Epistemonikos):** ~190 records before dedup; ~25 unique after dedup against PubMed + Embase (Epistemonikos is particularly useful for capturing Latin-American and Asian reviews indexed in LILACS and CNKI that PubMed misses).

---

## 5. Hand-searching

### 5.1 Reference lists
We will hand-search the reference lists of every included systematic review for additional eligible reviews.

### 5.2 Guideline documents (2020–2026)
We will scan the references and supplementary materials of the following guidelines for cited systematic reviews not captured by the database queries:
- **NCCN** — Breast Cancer Guidelines v2024–v2026
- **ESMO** — Loibl 2023 (PMID 38101773); Cardoso 2019 (PMID 31161190)
- **ASCO** — Park 2025 (PMID 40209128 — SLNB update); Brackstone 2021 (PMID 34279999 — axillary management)
- **St Gallen** — Curigliano 2017 (PMID 28838210); Burstein 2019/2021 (PMIDs 31373601, 34242744); Curigliano 2023 (PMID 37683978); Untch 2025 (PMID 40599897)
- **AGO** — Ditsch 2022 (PMID 36156915); Banys-Paluchowski 2022 (PMID 36186147); Park-Simon 2023/2024/2025 (PMIDs 37900552, 38894952, 40236659); Reimer 2025 (PMID 40983010)
- **EUSOMA** — Biganzoli 2019/2020 (PMIDs 31933581, 32217457); Rubio 2023 (PMID 38199146)
- **EUBREAST** — Gasparri 2022 (PMID 35766257); Weber 2023 (PMID 37126938)

### 5.3 Conference abstracts (2024-Q4 to 2026-Q2)
- ESMO Congress, San Antonio Breast Cancer Symposium (SABCS), ASCO Annual Meeting, EUBREAST Annual Meeting, EBCC.

### 5.4 Trial registries (for context, not for inclusion as reviews)
- ClinicalTrials.gov, EU CTR (EudraCT), JPRN, ANZCTR — to identify completed trials whose results will likely have been pooled in candidate reviews (e.g., NSABP B-51, Alliance A011202, ATNEC, AXSANA, INSEMA, SOUND).

### 5.5 PROSPERO registry
Search PROSPERO for in-progress umbrella reviews on the same topic, to confirm novelty.

---

## 6. Pilot deduplication and screening flow

The pilot search executed in the source repository yielded the following workflow:

| Stage | n records |
|---|---|
| PubMed/MEDLINE (raw, after SR/MA filter) | ~210 |
| EMBASE unique additions | ~140 |
| CDSR unique additions | ~10 |
| Epistemonikos unique additions | ~25 |
| **Total before dedup** | **~385** |
| After Zotero/Rayyan deduplication | ~310 |
| Excluded at title/abstract (off-topic, narrative, primary study) | ~250 |
| Full-text retrieved | ~60 |
| Excluded at full-text (insufficient SR methodology, wrong population, wrong intervention) | ~27 |
| **Included in pilot data extraction** | **33** |
| Plus relevant guidelines indexed for context | 28 |
| Plus prospective/randomized trials indexed for context | 22 |
| **Project repository total references** | **292** |

Notes on the pilot: of the 33 SRs identified, 5 are seminal reviews currently used as AMSTAR-2 calibration anchors:
- Xing 2006 (PMID 16921425) — first SR/MA on SLNB after NAC.
- Mocellin 2015 (PMID 26219232) — comprehensive MA on FNR predictors.
- Samiei 2021 (PMID 33881478) — pooled axillary pCR by molecular subtype.
- Swarnkar 2021 (PMID 33810544) — pooled FNR for MLNB and TAD.
- de Wild 2024 (PMID 38531689) — comprehensive SR on TAD marker technology and timing.
- Abdulla 2026 (PMID 41545613) — most recent MA comparing oncologic outcomes SLNB vs TAD.
- Boland 2025 (PMID 40009931) — MA on SPIO in NAC setting.

---

## 7. Search re-run policy

The complete search will be re-run within 30 days of manuscript submission. Any newly identified eligible review will be screened, AMSTAR-2-rated, and incorporated into the synthesis if it changes the direction or magnitude of any primary outcome estimate; otherwise it will be acknowledged in a post-hoc table without modifying the principal narrative.

---

*Pilot search documented for PROSPERO registration.*
