# Table 1B. Systematic reviews retained for SENSITIVITY ANALYSIS (n=10) — population-mixed cN0+cN+, intervention-adjacent (imaging/RT/NET), or other minor PICOS deviations

Sorted by year of publication. These 10 SRs deviated from the strict PICOS eligibility triage but were retained for **sensitivity analysis** because they share substantial topical overlap with the umbrella scope. Their inclusion or exclusion will be tested as a sensitivity layer in Section 3.4 of the manuscript, with explicit reporting of how their broader populations or alternative interventions modify the pooled estimates obtained from the 13 fully-eligible SRs (Table 1A). Per-SR borderline reasons are taken verbatim from the eligibility triage (`_amstar2_toolkit/eligibility_triage.json`).

| # | First author (year) | Journal | Design | k (primary studies) | N (participants) | Primary outcome reported | Borderline reason | PMID / DOI |
|---|---|---|---|---|---|---|---|---|
| 1  | Xing (2006)            | Br J Surg              | MA              | 21          | 1,273  | FNR of SLNB after NAC                                       | Population (P): inclusion criteria specify only "operable breast cancer" and pool cN0 + cN+ together without separating cN+ subgroup. Pooled IR/FNR estimates do not isolate biopsy-confirmed cN+. | 16329089 / 10.1002/bjs.5209 |
| 2  | Kelly (2009)           | Acad Radiol            | SR/MA           | 24          | 1,799  | Diagnostic accuracy of SLN mapping after neoadjuvant therapy | Population (P): "early-stage breast carcinoma" with mixed cN0/cN+ population (37% node-positive). Pooled SIR 89.6% and FNR 8.4% not stratified by pre-NAC nodal status. | 19345896 / 10.1016/j.acra.2009.01.026 |
| 3  | van Deurzen (2009)     | Eur J Cancer           | SR              | 27          | 2,148  | FNR of SLNB after NAC in invasive breast cancer             | Population (P): pools cN0 and cN+ together; abstract notes initially positive cN as a variable associated with decreased accuracy but does not present pre-specified separated cN+ pooled data. | 19716287 / 10.1016/j.ejca.2009.08.001 |
| 4  | Schipper (2014)        | Eur J Radiol           | SR              | 4           | 572    | Restaging cN+ patients after NAC by clinical exam, US, MRI, FDG-PET-CT, prediction model | Intervention (I): population matches but intervention is non-invasive imaging restaging rather than the surgical axillary techniques specified in the protocol; no quantitative pooling possible. | 25458227 / 10.1016/j.ejrad.2014.09.020 |
| 5  | Mocellin (2015)        | Int J Cancer           | MA              | 72          | 7,451  | FNR of SLNB after NAC in locally advanced BC; predictors    | Population (P): mixed cN0/cN+ in "locally advanced breast cancer" without explicit biopsy-proven cN+ inclusion requirement. Pooled FNR 14.2% and SIR 89.6% pertain to broader LABC population. | 26084763 / 10.1002/ijc.29644 |
| 6  | Krug (2018)            | Strahlenther Onkol     | SR              | 13          | see SR text | PMRT and regional nodal irradiation after NAC               | Intervention (I): methodology systematic but intervention is radiotherapy rather than axillary surgery. Includes pre-NAC cN status and ypN response stratification — partial relevance for LRR outcomes. | 29383405 / 10.1007/s00066-018-1270-x |
| 7  | Lin (2022)             | Ann Surg Oncol         | SR/MA           | 79          | 10,680 | FNR of SLNB after NAT; recurrence                            | Population (P): explicitly described as "initially cN±" — pools cN0 and cN+ together. Subgroup data exist but primary pooled FNR estimate (11.8%) mixes both populations. | 35018590 / 10.1245/s10434-021-11297-z |
| 8  | Vasigh (2024)          | Breast J               | MA              | 11          | 18,037 | NAC vs NET in HR+/HER2- cN+; nodal pCR and ALND rates       | Intervention (I): population matches but intervention contrast is between systemic therapies rather than axillary surgical techniques after NAC; relevant NAC arm subset (n=14,330) may yield extractable ypN0 data. | 39742366 / 10.1155/2024/8866756 |
| 9  | Boland (2025)          | Eur J Surg Oncol       | SR/MA           | 5           | 374    | SPIO vs RI for SLN detection after NACT                      | Population (P): includes both cN0 and cN+ patients without separation. Outcomes are detection rates rather than ypN0 conversion or FNR for cN+ patients specifically. | 40009931 / 10.1016/j.ejso.2025.109684 |
| 10 | Ding (2025)            | J Cancer Res Ther      | SR/MA           | 16          | see SR text | PMRT in ypN0 BC after NAC; LRR (RR 0.52) and survival       | Population (P): abstract states focus on "clinically lymph node-negative patients" (cN0 → ypN0), contradicting protocol cN+ requirement. Needs full-text verification of pre-NAC nodal status; outcomes (LRR) are directly relevant. | 40317154 / 10.4103/jcrt.jcrt_1279_24 |

**Footer.** All 10 borderline SRs share at least one primary study with the 13 fully-eligible SRs (Table 1A). Sensitivity-analysis strategy: (i) re-pool primary outcomes after sequentially adding each borderline SR's pooled estimate as an additional study; (ii) report the change in summary effect (Δ) and its 95% CI overlap with the eligible-only pooled estimate; (iii) flag any borderline SR whose inclusion shifts the eligible-only point estimate by >10% relative or pushes the 95% CI to cross the clinical threshold (FNR 10%). Per-SR primary outcomes will be re-extracted at full-text level for the sensitivity layer prior to journal submission. Excluded SRs (n=10) with reasons are catalogued in Supplementary File S4.
