p16 is a tumor suppressor gene that plays a central role in the regulation of the cell cycle. In squamous cervical cancers, overexpression of p16 is induced by HPV and associated with the carcinogenesis of cervical epithelia. The aim of this study was to determine whether immunostaining of p16 is useful in detecting adenocarcinomas of the cervix uteri in histologic and cytologic routine specimens. A total of 45 surgical specimens, including 18 cases of invasive carcinoma, 8 cases of adenocarcinoma in situ, 4 cases of endocervical glandular atypia (cervical glandular intraepithelial neoplasia), and 15 reactive lesions of the endocervical glands were immunostained using a specific anti-human p16 monoclonal antibody (clone E6H4, mtm laboratories AG, Heidelberg, Germany). Furthermore, immunocytochemical analysis was performed on 10 preoperative ThinPrep cytologic samples with abnormal glandular cells and compared with the human papillomavirus status as assessed with the Hybrid Capture II test. p16 was detected immunohistochemically in all 26 cases of adenocarcinoma of the cervix uteri, including 18 invasive and 8 in situ carcinomas. Only a focal expression was evidenced in the four specimens with endocervical glandular atypia, and no reaction was found in reactive lesions. Also, the immunocytochemical analysis on the 10 ThinPrep specimens evidenced a strong expression of p16 in neoplastic endocervical cells. In all cases this was associated with a high-risk HPV-positive typing. p16 is a useful marker for the detection of the adenocarcinoma of the cervix uteri and its precursors. The immunocytochemical detection on ThinPrep specimens may contribute to an early detection of endocervical lesions.

The aim of the study was to evaluate the immunohistochemical expression of p16INK4a as a marker of progression risk in low-grade dysplastic lesions of the cervix uteri. p16INK4a immunohistochemistry was performed on 32 CIN1 with proven spontaneous regression of the lesion in the follow-up (group A), 31 (group B) with progression to CIN3 and 33 (group C) that were randomly chosen irrespective of the natural history of the lesion. p16INK4a staining pattern was scored as negative (less than 5% cells in the lower third of dysplastic epithelium stained), as focally positive (< or = 25%) and as diffuse positive (> 25%). A diffuse staining pattern was detected in 43.8% of CIN1 of group A, 74.2% of group B and 56.3% of group C. No p16INK4a staining was detected in 31.3% and 12.9% CIN1 lesions of groups A and B, respectively. Overall, 71.4% and 37.8% of p16INK4a-negative and diffusely positive CIN1 had regressed at follow-up, whereas 28.6% and 62.2% negative and diffusely positive CIN1 were progressed to CIN3, respectively (P < 0.05). All CIN3 lesions analyzed during follow-up of group B were diffusely stained for p16INK4a. Although p16INK4a may be expressed in low-grade squamous lesions that undergo spontaneous regression, in this study, CIN1 cases with diffuse p16INK4a staining had a significantly higher tendency to progress to a high-grade lesion than p16INK4a-negative cases. p16INK4a may have the potential to support the interpretation of low-grade dysplastic lesions of the cervix uteri.

As only a minority of low-grade dysplastic lesions of the cervix uteri will eventually progress to carcinoma, predicting the behavior of these lesions could be of high value in clinical practice. The aim of the study was to evaluate p16 ink4a and L1 as immunohistochemical markers of the biologic potentiality of low-grade dysplasia of the uterine cervix. The study included 38 conization specimens with coexisting cervical intraepithelial neoplasia grade 1 (CIN1) and 3 (CIN3) (group A) and 28 punch biopsies from women with CIN1 and proven spontaneous regression in the follow-up (group B). In group A, all CIN3 were p16 ink4a positive (p16+) and L1 negative (L1-). The CIN1 of this group were p16+L1- and p16+L1+ in 68.42% and 31.57%, respectively. No other expression pattern was found in this group. In group B, the p16+L1-, p16+L1+, p16-L1+, and p16-L1- patterns were found in 3.57%, 25%, 14.29%, and 57.14%, respectively. Overall, 96.29% p16+L1- CIN1 were found in group A, whereas all the p16-L1+ and p16-L1- CIN1 were found in group B. A significant difference between staining pattern distributions of group A and B was observed (P<0.0001). The results of the study show that p16 ink4a and L1 immunohistochemistry can be helpful for estimating the biologic potentiality of low-grade squamous cervical lesions. Particularly in cases in which the grade of the lesion is morphologically difficult to assess, the p16/L1 expression pattern could be useful for planning the clinical management of these women.

AimsRegulated intramembrane proteolysis has been shown to be an important mechanism for oncogenic activation of epithelial cell adhesion molecule (EpCAM) through nuclear translocation of the intracellular domain EpICD. Recent studies have identified new membrane-bound EpCAM variants. To evaluate the prevalence of two membranous EpCAM variants in human tumours, we performed a large-scale expression analysis using specific antibodies against the extracellular domain EpEX (MOC-31 clone) and the intracellular domain EpICD (9-2 clone) of the EpCAM antigen by immunohistochemistry.Material and methodsTwo multi-tissue microarrays (TMA) series containing 1564 tissue samples each of 53 different histological tumour types were stained and compared. One TMA was stained for EpEX and one for EpICD. Membranous full-length EpCAM (EpCAMMF) expression in tissues was defined by the expression of EpEX and EpICD, while the truncated variant of EpCAM (EpCAMMT) was characterised by a significant loss of membranous EpICD expression compared with EpEX expression.ResultsWe defined tumours with high EpCAMMT expression (ie, cancers of the endometrium and bladder), tumours with intermediate (ie, gastric, pancreatic, colorectal and oesophageal cancer) and tumours with low rates of expression of the EpCAMMT variant (ie, lung, ovarian, gallbladder, breast and prostate cancer).ConclusionsOur results indicate that loss of membranous EpICD expression is a common event in human epithelial carcinomas, arguing for the expression of different degrees of EpCAMMF and EpCAMMT variants across the most important tumour entities. Future studies evaluating the prognostic and predictive role of these variants in human malignancies, especially in patients treated with EpCAM-specific antibodies, are clearly warranted.

This study demonstrates for the first time that loss of membranous EpICD expression is a frequent event and predicts poor prognosis in patients with pancreatic cancer. Additional studies evaluating the predictive and prognostic value of the expression of different membranous EpCAM variants are warranted in epithelial cancers.

Regulated intramembrane proteolysis (RIP) has been shown to be an important mechanism for oncogenic activation of EpCAM through nuclear translocation of the intracellular domain EpICD. Recently, we identified two different membranous EpCAM variants namely EpCAM MF (full-length) and EpCAM MT (truncated) to be expressed in the majority of human epithelial tumors. The aim of our study was to evaluate the potential role of these two protein variants as additional prognostic biomarkers in colorectal cancer. In most studies only one antibody targeting the extracellular domain of EpCAM (EpEX) has been used, whereas in the present study additionally an antibody which detects the intracellular domain (EpICD) was applied to discriminate between different EpCAM variants. Colorectal cancer (CRC) is a common cause of cancer-related mortality worldwide and approximately 30% of patients present with advanced disease at diagnosis.

INK4a and conventionally counterstained with haematoxylin. The intensity of immunostaining in cases of squamous intraepithelial lesion (SIL) was assessed using a 0-3 scoring system. Interobserver agreement was calculated by k statistics. Results: Expression of p16INK4a was detected in 3 of 23 cases of WNL, 4 of 6 cases of LSIL, all cases of HSIL, 5 of 16 cases of ASC-US and 13 of 16 cases of ASC-H. Excluding two cases with no residual dysplastic cells in the immunocytochemistry, all cases of cervical intraepithelial neoplasia (CIN)2 or CIN3 at follow-up expressed p16INK4a and none of the p16 INK4a -negative cases showed a high-grade lesion at follow-up. No evident differences in pattern or intensity of p16INK4a expression were observed between the specimens of the study and control groups. Interobserver agreement was significantly better in the study group than in the group with conventional immunostaining (combined k 0.773 v 0.549; p,0.05), and still better, albeit statistically not significant, than with conventional immunostaining and cervical smear test together (combined k 0.773 v 0.642). Conclusion: Immunocytochemistry with p16INK4a and modified Papanicolaou counterstain may add to the cervicovaginal cytology the full potentiality of p16INK4a without the need of a further slide and the risk of loss of dysplastic cells, yet maintaining the typical morphological features of the smear test.

Although the diagnostic criteria of in-situ and invasive adenocarcinomas of the cervix uteri are well established, the differentiation from benign mimics may be difficult and the morphologic features of the precursors of endocervical adenocarcinoma are still debated. In this study, we evaluated the usefulness of p16ink4a (p16), ProEX C, and Ki-67 for the diagnosis of endocervical adenocarcinoma and its precursors. Immunohistochemistry with p16, ProEX C, and Ki-67 was performed in 82 glandular lesions including 15 invasive adenocarcinomas, 29 adenocarcinomas in situ (AIS), 22 non-neoplastic samples, and 16 cases of glandular dysplasia (GD), which showed significant nuclear abnormalities but did not meet the diagnostic criteria for AIS. The immunohistochemical expression pattern was scored according to the percentage of the stained cells (0, 1+, 2+, and 3+ when 0% to 5%, 6% to 25%, 26% to 50%, and more than 50% of the cells were stained, respectively) and was evaluated for each antibody. p16 was at least focally expressed (1+ or more) in 14 of 15 invasive adenocarcinomas, in all AIS and in 7 negative samples. ProEX C and Ki-67 both scored 1+ or more in all adenocarcinomas and AIS and in 8 and 6 negative samples, respectively. Of the GD 15, 14, and 15 expressed p16, ProEX C, and Ki-67, respectively. The score differences between neoplastic and non-neoplastic samples were highly significant for each marker (P<0.001); however, the score distribution by marker differed significantly only in GD (P=0.006) in which, compared with the other markers, p16 showed more often a 3+ pattern. Our study shows that p16, Ki-67, and ProEX C may be helpful for the diagnosis of glandular lesions of the cervix uteri and may also improve the diagnostic accuracy of endocervical GD. In particularly problematic cases, the combination of p16 and a proliferation marker can provide additional help for the interpretation of these lesions.