p16INK4a/Ki-67 dual labelling as a marker for the presence of high-grade cancer cells or disease progression in urinary cytopathology

Immunocytochemical expression of Ki-67/p16 in normal, atypical, and neoplastic cells in urine cytology using BD SurePath™ as preparation method

Objective:

The objective of this study was to investigate the expression of Ki-67/p16 in urothelial cells in cytological material.

Materials and Methods:

There were 142 urines including normal controls, anonymous rest urine, controls after treatment for urothelial carcinoma (UC) and newly diagnosed UC. Immunocytochemistry for ki-67/p16 dual staining kit was performed on all specimens.

Results:

Eight high-grade UC and six anonymous specimens showed dual positivity. None of the low-grade UC or the control specimens after treated UC showed dual staining. Fifteen of 84 (17.8%) symptomatic cases were negative for both markers, and 59/84 (70.2%) showed positivity for both but not dual staining. Twenty-seven of 84 cases were positive for either Ki-67 (n = 22) or p16 (n = 5). Normal controls and benign specimens were negative for p16.

Conclusions:

Co-expression of p16/Ki-67 in the same cells was found in 16.6% of the cases. All were high grade, and co-expression seems to have limited practical impact as an additional marker in urine cytology. Any positivity for p16 alone strongly indicates malignancy. Negative p16 accompanied by a positive Ki-67 rate at 5% or more could be considered as an additional marker for further clinical follow-up. Both markers, co-expressed and separate, can give additional information in follow-up patients after treatment for UC.

Stratification of HPV-induced cervical pathology using the virally encoded molecular marker E4 in combination with p16 or MCM

High-risk human papillomavirus (HPV) types cause cervical lesions of varying severity, ranging from transient productive infections to high-grade neoplasia. Disease stratification requires the examination of lesional pathology, and possibly also the detection of biomarkers. P16(INK4a) and MCM are established surrogates of high-risk HPV E6/E7 activity, and can be extensively expressed in high-grade lesions. Here we have combined these two cellular biomarkers with detection of the abundant HPV-encoded E4 protein in order to identify both productive and transforming lesions. This approach has allowed us to distinguish true papillomavirus infections from similar pathologies, and has allowed us to divide the heterogeneous CIN2 category into those that are CIN1-like and express E4, and those that more closely resemble nonproductive CIN3. To achieve this, 530 lesional areas were evaluated according to standard pathology criteria and by using a multiple staining approach that allows us to superimpose biomarker patterns either singly or in combination onto an annotated hematoxylin and eosin (H&E) image. Conventional grading of neoplasia was established by review panel, and compared directly with the composite molecular pathology visualized on the same tissue section. The detection of E4 coincided with the onset of vacuolation, becoming abundant in koilocytes as the MCM marker declined and cells lost their defined nuclear margins as visualized by standard H&E staining. Of the dual marker approaches, p16(INK4a) and E4 appeared most promising, with E4 generally identifying areas of low-grade disease even when p16(INK4a) was present. Extensive p16(INK4a) expression usually coincided with an absence of E4 expression or its focal retention in sporadic cells within the lesion. Our results suggest that a straightforward molecular evaluation of HPV life-cycle deregulation in cervical neoplasia may help improve disease stratification, and that this can be achieved using complementary molecular biomarker pairs such as MCM/E4 or, more promisingly, p16(INK4a)/E4 as an adjunct to conventional pathology.

Biomarkers in bladder cancer: translational and clinical implications

Bladder cancer is associated with high recurrence and mortality rates. These tumors show vast heterogeneity reflected by diverse morphologic manifestations and various molecular alterations associated with these disease phenotypes. Biomarkers that prospectively evaluate disease aggressiveness, progression risk, probability of recurrence and overall prognosis would improve patient care. Integration of molecular markers with conventional pathologic staging of bladder cancers may refine clinical decision making for the selection of adjuvant and salvage therapy. In the past decade, numerous bladder cancer biomarkers have been identified, including various tumor suppressor genes, oncogenes, growth factors, growth factor receptors, hormone receptors, proliferation and apoptosis markers, cell adhesion molecules, stromal factors, and oncoproteins. Recognition of two distinct pathways for urothelial carcinogenesis represents a major advance in the understanding and management of this disease. Nomograms for combining results from multiple biomarkers have been proposed to increase the accuracy of clinical predictions. The scope of this review is to summarize the major biomarker findings that may have translational and clinical implications.