Table 1.

Extensive histopathological tumor regression criteria analyses in postchemotherapy engrafted OVA1XR tumor

MiceFibrosisNecrosisInflam-mationFoamy macro-phagesCalci-ficationHemo-siderinForeign-body giant cellsGiant tumor cellsPattern of tumor infiltrationbChemotherapy response based on histopathological featurese
Short-term responsea
Placebo101+000001+1+NHR
201+1+00001+1+NHR
31+1+00CDc001+1+NHR
41+01+00001+1+NHR
51+1+000001+1+NHR
Cisplatin62+00000001+NHR
72+00001+01+1+NHR
81+00001+01+1+NHR
91+0000001+1+NHR
101+1+000001+1+NHR
Lurbinectedin112+1+1+002+02+2+NHR
122+01+0CD2+02+2+NHR
132+02+002+02+2+NHR
141+01+001+01+1+NHR
152+1+002+02+1+NHR
Lurbinectedin + cisplatin163+02+002+03+2+MHR
173+01+002+03+3+GHR
183+02+0CD2+03+3+GHR
191+02+001+03+3+MHR
203+01+1+CD2+03+3+GHR
Long-term responsea
Cisplatin-RL211+1+000001+1+NHR
221+2+1+00001+1+NHR
231+0000001+1+NHR
Lurbinectedin-RL241+01+001+01+1+NHR
251+01+00001+1+NHR
263+01+002+03+2+MHR
27NV dNVNVNVNVNVNVNVNVGHR
Lurbinectedin + cisplatin-RL283+02+002+03+3+GHR
293+01+00003+3+GHR
30NVNVNVNVNVNVNVNVNVGHR
31NVNVNVNVNVNVNVNVNVGHR
  • aFor short-term response studies, animals were sacrificed on day 21 of treatment, whereas for long-term-response studies, mice were sacrificed 42 days after the end of treatment when the tumor had relapsed.

  • bPattern and extent of tumor infiltration was classified as follows: 1+, macroscopic large confluent tumor mass(es); 2+, multiple small tumor foci; 3+, scattered solitary tumor cells or complete absence of residual tumor. The remaining regression criteria were graded as follows: 0/1+, no or only minimally presence of the regression criterion within the specimen; 2+, focal occurrence of the respective regression criterion; 3+, widespread occurrence of the respective regression criterion.

  • cCD, dystrophic calcification.

  • dNV, not evaluated by complete tumor regression. Characterized by the absence of macro- and microscopic lesions.

  • eThree histopathological response categories were defined based on the number of regression criteria: NHR, no histopathological response (≤1 regression criteria [3+] present); MHR, moderate (2 regression criteria [3+] present), and GHR, good histopathological response (≥3 regression criteria [3+] present).