Template:Immunohistochemistry evaluation of invasive breast cancer: Difference between revisions

Ki-67 index is most feasibly quantified by a hot spot method,<ref group=notes>Besides from a hot spot method of Ki67 counting, there is also a ''IKWG global average'' method which is more comprehensive. However, the inter-observer difference between the hot spot method and the 'IKWG global average'' is not statistically significant, and has not shown any significant difference in clinical outcome (theoretically, the area of highest Ki-67 proliferative index is probably most likely to correlate with malignant transformation and risk of metastasis, making the hot spot both more straightforward and clinically relevant than a global average).<br>'''Reference and instructions for the ''IKWG global average'' method:'''{{cite journal|last1=Dowsett|first1=M.|last2=Nielsen|first2=T. O.|last3=A'Hern|first3=R.|last4=Bartlett|first4=J.|last5=Coombes|first5=R. C.|last6=Cuzick|first6=J.|last7=Ellis|first7=M.|last8=Henry|first8=N. L.|last9=Hugh|first9=J. C.|last10=Lively|first10=T.|last11=McShane|first11=L.|last12=Paik|first12=S.|last13=Penault-Llorca|first13=F.|last14=Prudkin|first14=L.|last15=Regan|first15=M.|last16=Salter|first16=J.|last17=Sotiriou|first17=C.|last18=Smith|first18=I. E.|last19=Viale|first19=G.|last20=Zujewski|first20=J. A.|last21=Hayes|first21=D. F.|title=Assessment of Ki67 in Breast Cancer: Recommendations from the International Ki67 in Breast Cancer Working Group|journal=JNCI Journal of the National Cancer Institute|volume=103|issue=22|year=2011|pages=1656–1664|issn=0027-8874|doi=10.1093/jnci/djr393}}</ref> Hot spots are areas in which Ki-67 staining is particularly higher relative to the adjacent tumor areas.<ref name="ColemanJang2017">{{cite journal|last1=Coleman|first1=William B.|last2=Jang|first2=Min Hye|last3=Kim|first3=Hyun Jung|last4=Chung|first4=Yul Ri|last5=Lee|first5=Yangkyu|last6=Park|first6=So Yeon|title=A comparison of Ki-67 counting methods in luminal Breast Cancer: The Average Method vs. the Hot Spot Method|journal=PLOS ONE|volume=12|issue=2|year=2017|pages=e0172031|issn=1932-6203|doi=10.1371/journal.pone.0172031}}</ref> Usually, the invasive edge of a tumor is a hot spot.<ref name="ColemanJang2017"/> When a tumor had several hot spots, the “hottest” spot is selected.<ref name="ColemanJang2017"/> Aim to count at least 500 cells in each case, but this is not always possible in cases with low tumor cell density and small tumor size.<ref name="ColemanJang2017"/> Also aim to include at least three high-power (×40 objective) fields. <ref>{{cite web|url=https://www.ki67inbreastcancerwg.org/wp-content/uploads/2018/12/Ki67-Phase-3b-WS-protocol-v1.pdf|title=Ki67-QC international working group: whole section scoring protocol (global method)|date=2018-11-29|website=International Ki67 in Breast Cancer Working Group}}</ref> If a comparisons must be made between core biopsies and sections from an excision, evaluation of the latter should be across the whole tumor.<ref name="DowsettNielsen2011"/> Only nuclear staining counts. Staining intensity of a positive nucleus is not relevant.<ref name="DowsettNielsen2011"/>