Table 2. Methods of defining tumour budding among included studies.
| Author | Year | Staining method | Definition of budding focus | Tumour budding method |
|---|---|---|---|---|
| Hase | 1993 | H&E | Cluster of <5 cancer cells | Graded into two groups: none/mild or moderate/severe at invasive front |
| Ueno | 2002 | H&E | Cluster of <5 cancer cells | >5 Budding foci |
| Okuyama | 2002 | H&E | Cluster of <6 cancer cells | ⩾1 Budding focus (Morodomi) |
| Okuyama | 2003 | H&E | Cluster of >4 cancer cells | ⩾1 Budding focus |
| Ueno | 2004 | H&E | Cluster of <5 cancer cells | >9 Budding foci |
| Prall | 2005 | Cytokeratin/IHC | Cluster of <5 cancer cells | >24 Budding foci |
| Wang | 2005 | H&E | Cluster of >4 cancer cells | ⩾1 Budding focus (Morodomi) |
| Yasuda | 2007 | H&E | Cluster of an unspecified number of cancer cells | ⩾1 Budding focus (Hase) |
| Kanazawa | 2008 | H&E | Cluster of an unspecified number of cancer cells | Mild: <1/3 invasive margin Moderate: 1/3–2/3 invasive margin Severe: >2/3 invasive margin |
| Nakamura | 2008 | H&E | Cluster of an unspecified number of cancer cells | As per Kanazawa above |
| Yamauchi | 2008 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno modified) |
| Lugli | 2009 | Cytokeratin/IHC | Cluster of <6 cancer cells | >16 Buds per hpf |
| Ogawa | 2009 | Cytokeratin/IHC | Cluster of <5 cancer cells | >9 Budding foci |
| Wang | 2009 | H&E | Cluster of <5 cancer cells | ⩾1 Budding focus |
| Homma | 2010 | H&E | Cluster of <5 cancer cells | Graded none, mild, mod, severe but did not delineate what comprised each |
| Kajiwara | 2010 | H&E | Cluster of <5 cancer cells | >9 Budding foci |
| Komori | 2010 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno modified) |
| Tateishi | 2010 | H&E | Cluster of <5 cancer cells | ⩾1 Budding focus (Ueno) |
| Akishima-Fukasawa | 2011 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Reggiani Bonetti | 2011 | H&E | Cluster of <6 cancer cells | >4 Budding foci (Ueno) |
| Betge | 2012 | H&E | Cluster of <5 cancer cells | >9 Budding foci (Ueno modified) |
| Nakadoi | 2012 | H&E | Cluster of <6 cancer cells | >4 Budding foci (Ueno modified) |
| Sert Bektas | 2012 | H&E | Cluster of <5 cancer cells | >9 Budding foci (Ueno modified) |
| Wada | 2013 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Zlobec | 2012 | Cytokeratin/IHC | Cluster of <6 cancer cells | >5 Budding foci |
| Nishida | 2014 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Huh | 2014 | H&E | Cluster of <5 cancer cells | >5 Budding foci |
| Lai | 2014 | H&E | Cluster of <5 cancer cells | >9 Budding foci (Ueno modified) |
| Ryu | 2014 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Gilardoni | 2014 | NS | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Macias-Garcia | 2014 | NS | Cluster of <5 cancer cells | >10 Budding foci (Ueno modified) |
| Tristante | 2014 | NS | NS | NS |
| Barresi | 2016 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
| Miyachi | 2015 | H&E | Cluster of <5 cancer cells | >4 Budding foci (Ueno) |
Abbreviations: H&E=haematoxylin and eosin; IHC=Immunohistochemistry; NS, not significant.