Likewise, concerning the results obtained when applying our gene signatures to the ICR cohort we noted that gene signatures could disagree for some tumors in the assignment of histologic grade 2 into grade 1-like or grade 3-like.
The creative constraints of the prompts also harken back to the class assignments of grade school and are meant to make the task of drawing something easy and manageable.
Mis-assignments of grade I to grade III or vice versa are rarely reported, but grade II tumors usually show the lowest degree of concordance.
The appraisal group did not set criteria for the assignment of the grades.
Several different guidelines have been proposed in the literature for assignment of nuclear grade [e.g. [ 2, 11]], however none of these allow incorporation of heterogeneity of grade which has been observed by others and by us [e.g. [ 11, 12, 22]], or mixed architecture [ 22].
Nuclear grade is used as a major determinant of therapy for these patients, although assignment of a grade is a subjective evaluation and there is inconsistent evidence for prognostic importance [ 1- 11].
In this context, medulloblastomas in particular can be highly malignant, as evidenced by their assignment of WHO grade IV, but their overall, progression-free, and 5-year survival rates are comparable to those of ependymoma, and far exceed those of GBM [11][12][13].
Of these, 91 cases permitted complete assignment of WHO grading.
In part this limitation may be attributable to the considerable interobserver variability in the assignment of Gleason grade [ 9].
A large series study, conducted on 575 women affected by EOC, optimally surgically debulked without macroscopic residual disease, showed that tumor cell type was both more reproducible and provided superior prognostic information compared with assignment of tumor grade [ 26, 27].
