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BackgroundKi67 labeling index (Ki67 LI), the percentage Ki67 immunoreactive cells, is a measure of tumor proliferation, with important clinical relevance in breast cancer, and it is extremely important to standardize its evaluation.AimTo test the efficacy of computer assisted image analysis (CAIA) applied to completely digitized slides and to assess its feasibility in routine practice and compare the results obtained using two different Ki67 monoclonal antibodies.Materials and methods315 consecutive breast cancer routinely immunostained for Ki-67 (223 with SP6 and 92 with MM1 antibodies previously examined by an experienced pathologist, have been re-evaluated using Aperio Scanscope Xs.ResultsMean human Ki67 LI values were 36%± 14.% and 28% ± 18% respectively for SP6 and MM1 antibodies; mean CAM Ki67 LI values were 31%± 19% and 22% ± 18% respectively for SP6 and MM1. Human and CAIA evaluation are statistically highly correlated (Pearson: 0.859, p<0.0001), although human LI are systematically higher. An interobserver variation study on CAIA performed on 84 cases showed that the correlation between the two evaluations was linear to an excellent degree.DiscussionOur study shows that a) CAIA can be easily adopted in routine practice, b) human and CAIA Ki67 LI are highly correlated, although human LI are systematically higher, c) Ki67 LI using different evaluation methods and different antibodies shows important differences in cut-off values.

S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed. The levels of S100A1 mRNA detected by quantitative RT-PCR analysis of frozen tissues from seven clear cell, five papillary, and six chromophobe renal cell carcinomas, four oncocytomas, and nine samples of normal renal tissues adjacent to neoplasms were compared with the immunohistochemical detection of protein expression. Clear cell and papillary renal cell carcinomas showed positive reactions for S100A1 in 30 out of 41 tumors (73%) and in 30 out of 32 (94%) tumors, respectively. Thirty-seven renal oncocytomas out of 40 (93%) were positive for S100A1, whereas 48 of 51 (94%) chromophobe renal cell carcinomas were negative. S100A1 protein was detected in all samples of unaffected and fetal kidneys. S100A1 mRNA was detected by RT-PCR in all normal kidneys and renal cell neoplasms, although at very different levels. Statistical analyses comparing the different expression of S100A1 in clear cell and chromophobe renal cell carcinomas observed by immunohistochemical and RT-PCR methods showed significant values (Po0.001), such as when comparing by both techniques the different levels of S100A1 expression in chromophobe renal cell carcinomas and oncocytomas (Po0.001). Our study shows that S100A1 protein is expressed in oncocytomas, clear cell and papillary renal cell carcinomas but not in chromophobe renal cell carcinomas. Its immunodetection is potentially useful for the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma. Further, S100A1 protein expression is constantly detected in the normal parenchyma of the adult and fetal kidney.

Accurate classification of nonsmall cell lung cancers is of paramount clinical relevance, as novel chemotherapeutic agents show different efficacy in adenocarcinomas (ADCs) compared with squamous cell carcinomas (SQCCs). Cyto and histomorphology may sometimes be insufficient for this distinction and immunohistochemistry may improve diagnostic accuracy. The measurement of miR-205 may be another tool for the distinction between ADC and SQCC. The aim of our study was to compare morphologic and immunohistochemical classification with the relative quantification of miR-205 and miR-21 insurgically resected and well-characterized lung tumors (25 ADCs, 24 SQCCs, 1 adenosquamous). The miR-21 relative levels were similar in SQCC and ADC, whereas the miR-205 relative levels were lower in ADC (P<0.0001). The miR-205 sample score value, determined according to Lebanony et al, was higher in ADC (range, 2.8 to 9.08) compared with SQCC (range, -4.17 to 2.445) (P<0.0001). Accordingly, 22 tumors were classified as ADC and 28 tumors as SQCC, although 8 cases (2 SQCCs and 6 ADCs) were in the range of "near cutoff values." Four cases classified as SQCC (according to the sample score method) corresponded to cases classified as ADC on the basis of morphoimmunohistochemical evaluation. In conclusion, the relative quantification of miR-205 and miR-21 seems to be a promising diagnostic tool. However, the molecular approach is still not completely satisfactory as it may misclassify a non-negligible percentage of cases. Therefore, it cannot be used as a substitute of accurate morphologic and immunophenotypical characterization of tumors, but could be used as an adjunctive diagnostic criterion in selected cases.

Dual staining for p16 and Ki-67 demonstrated good reproducibility, confirming its robustness, which is a necessary prerequisite for its adoption as a triage test in cervical cancer screening programs that use human papillomavirus DNA as a primary test. Cancer Cytopathol 2017;125:212-220. © 2016 American Cancer Society.