Gleason Stereotypes

Presence of perineural invasion is the category III prognostic variable and is associated with increased incidence of extraprostatic extension and aggressive phenotypes.21Data varies across studies with a maximum percentage of about 90% in a study conducted by Merrilees AD et al 84and minimum of 16% and 17% in studies conducted by Nelson et al82 & Quinn et al83 respectively. In present study,38% of CaPs showed perineural invasion. Studies having more number of well differentiated tumors have low percentages of evidence of PNI while studies with more number of high grade tumors have high percentages of evidence of PNI. We had 39 cases of high grade tumors, so 38% of cases showing PNI was attributable to this reason.
7.Presence of adjacent PIN.
Table 6.7: Percentage of cases showing presence of adjacent PIN
8.Total percentage of cases in each score in different studies on Ki67 expression in prostate carcinoma. Gleason scoring system is the most important prognostic factor in CaP,hence several studies on emerging biomarkers are studied in correlation to Gleason score. Several methods for grouping of Gleason scores in prognostic categories have been proposed. Gleason scores 2 to 4 behave similarly and can be grouped. Gleason scores 8 to 10 are usually grouped together as they represent poorly differentiated tumors. Gleason score 7 is a distinct entity with prognosis intermediate between that of Gleason scores 5-6 and 8 to 10, respectively.21Hence we grouped the patients into four groups wherein Gleason score of 2-4 represent well differentiated tumors, score 5&6 intermediate grade tumors, score 7 moderately differentiated tumors and score 8 and above high grade tumors. The various studies on Ki67 expression use different grouping of Gleason scores. The studies mentioned in the table used same system as followed in present study and the comparative data is presented as