Background: Staging of melanoma includes quantification of a proliferation index, i.e., presumed melanocytic\nmitoses of H&E stains are counted manually in hot spots. Yet, its reproducibility and prognostic impact increases\nby immunohistochemical dual staining for phosphohistone H3 (PHH3) and MART1, which also may enable fully\nautomated quantification by image analysis. To ensure manageable workloads and repeatable measurements in\nmodern pathology, the study aimed to present an automated quantification of proliferation with automated hot-spot\nselection in PHH3/MART1-stained melanomas.\nMethods: Formalin-fixed, paraffin-embedded tissue from 153 consecutive stage I/II melanoma patients was\nimmunohistochemically dual-stained for PHH3 and MART1. Whole slide images were captured, and the number\nof PHH3/MART1-positive cells was manually and automatically counted in the global tumor area and in a manually and\nautomatically selected hot spot, i.e., a fixed 1-mm2 square. Bland-Altman plots and hypothesis tests compared manual\nand automated procedures, and the Cox proportional hazards model established their prognostic impact.\nResults: The mean difference between manual and automated global counts was 2.9 cells/mm2 (P = 0.0071) and 0.23\ncells per hot spot (P = 0.96) for automated counts in manually and automatically selected hot spots. In 77 % of cases,\nmanual and automated hot spots overlapped. Fully manual hot-spot counts yielded the highest prognostic performance\nwith an adjusted hazard ratio of 5.5 (95 % CI, 1.3ââ?¬â??24, P = 0.024) as opposed to 1.3 (95 % CI, 0.61ââ?¬â??2.9, P = 0.47) for\nautomated counts with automated hot spots.\nConclusions: The automated index and automated hot-spot selection were highly correlated to their manual\ncounterpart, but altogether their prognostic impact was noticeably reduced. Because correct recognition of only\none PHH3/MART1-positive cell seems important, extremely high sensitivity and specificity of the algorithm is\nrequired for prognostic purposes. Thus, automated analysis may still aid and improve the pathologistsââ?¬â?¢ detection\nof mitoses in melanoma and possibly other malignancies.
Loading....