Table 2

Score categorising the pathological response to systemic chemotherapy in ovarian cancer8

Criteria for chemotherapy response grade (CRG)*
CRG 1No or minimal tumour response. Mainly viable tumour with no or minimal regression-associated fibroinflammatory changes, limited to a few foci; cases in which it is difficult to decide between regression and tumour-associated desmoplasia or inflammatory cell infiltration
CRG 2Appreciable tumour response amid viable tumour that is readily identifiable. Tumour is regularly distributed, ranging from multifocal or diffuse regression-associated fibroinflammatory changes with viable tumour in sheets, streaks or nodules to extensive regression-associated fibroinflammatory changes with multifocal residual tumour, which is easily identifiable
CRG 3Complete or near-complete response with no residual tumour or minimal irregularly scattered tumour foci seen as individual cells, cell groups or nodules, up to 2 mm maximum size. Mainly regression-associated fibroinflammatory changes or, in rare cases, no or very little residual tumour in the complete absence of any inflammatory response. It is advisable to record whether there is no residual tumour or whether there is microscopic residual tumour present
  • *The term chemotherapy response grade is used instead of chemotherapy response score as in the original and subsequent publications to avoid confusion with the term cytoreductive surgery.