Usefulness of p16ink4a, ProEX C, and Ki-67 for the diagnosis of glandular dysplasia and adenocarcinoma of the cervix uteri.

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.

p16 ink4a and HPV L1 immunohistochemistry is helpful for estimating the behavior 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.