Markers of apoptosis in stage IB squamous cervical carcinoma

Immunohistochemical expression of apoptosis regulators in squamous cell carcinoma of the cervix and their association with human papillomavirus 16/18 subtypes

BACKGROUND

Human papillomavirus (HPV) infection is an important aetiological factor in squamous cell carcinoma (SCC) of the cervix. Limited studies have been focused on the differences between carcinogenesis of SCCs with and without HPV infection.

AIMS

The main goal of this study is to determine the expression of some of the apoptotic pathway regulators, including P53, Bax and Bcl2 in SCCs with and without high risk HPV 16/18 infection.

STUDY DESIGN

Cross sectional study.

METHODS

A total of 42 paraffin-embedded blocks with the histopathological diagnosis of invasive SCC with determined HPV 16/18 status were selected; half of them were HPV positive and the rest were negative. Afterwards, immunohistochemistry stained slides for p53, Bcl2 and Bax were evaluated with H-score, multiplicative and Additive Quick score by two pathologists; in cases of controversy about the results, the mean results were recorded.

RESULTS

Mean results and percentage of expression of our three markers were significantly higher in the HPV 16/18 infected group than in uninfected individuals: Respectively, the mean score for Bcl2, Bax and p53 staining according to H-scoring method was 68.5, 234, 106.4 in the HPV 16/18 infected group and 4.5, 218.8, 5.07 in the uninfected group; and the Multiplicative Quick score was 4, 14.6, 8.2 in the HPV 16/18 infected group and 3, 12.3, 3.5 in the uninfected group.

CONCLUSION

High risk HPVs possibly act in favour of apoptotic pathway inactivation. The significant difference in apoptotic pathway between SCCs with and without high risk HPVs suggests a different early carcinogenesis pathway.

Lymph node metastases, not human telomerase reverse transcriptase or p53 proteins, as the strongest prognostic factor for survival in early stage cervical cancer

AIM

Human telomerase reverse transcriptase (hTERT) is known to be significantly activated during immortalization, and p53 is thought to be a guardian of that apoptosis pathway in most cancer cells. The aim of this study was to assess the relationships among hTERT, p53 and various clinicopathological parameters of cervical cancer patients and overall survival.

METHODS

We used immunohistochemical methods to examine the expression of hTERT and p53 proteins in 45 paraffin-embedded pathological samples of early stage (IA-IIA) cervical cancer.

RESULTS

Thirty-seven of 45 (82.2%) cervical cancer slides exhibited hTERT activation. Twenty-eight of these slides with activated hTERT (75.7%) were also found to be positive for mutant p53 protein (P < 0.05). Neither of both was found to be prognostic in Kaplan-Meier curves (Figs 2,3). The survival rate varied greatly (from 86.54% to 42.86%) in a particular order: hTERT activation > mutated p53 > deep stromal invasion > pelvic nodal metastases. The findings also demonstrated that stromal invasion was no longer a significant prognostic factor (P = 0.16), but that nodal status was an adverse prognostic with a hazard ratio of 8.48 (1.89-37.98) after adjustment.

CONCLUSIONS

Although expression of both hTERT and mutant p53 increase in early stage cervical cancer, neither was found to be prognostic. Lymph node metastases was the most powerful prognostic factor associated with survival among hTERT, p53 and various clinicopathological parameters.

Double immunofluorescence shows coexpression of Bcl-x with GFAP in a variety of glial lesions

Bcl-x is an important member of the bcl-2 family of proteins that has been shown to be expressed by both native nervous system tissue and several nervous system tumors. Its anti-apoptotic activity is believed to contribute to nervous system tumorigenesis. We seek to compare the staining characteristics of Bcl-x and GFAP in various neuronal and glial lesions, both neoplastic and non-neoplastic. We also use a double immunofluorescence technique to assess for coexpression of Bcl-x and GFAP by the same lesional cells. Forty cases of brain tumors and reactive brain conditions were reviewed. The former included astrocytomas, GBMs, ependymomas, oligodendrogliomas, gangliogliomas, subependymomas and neurocytomas. The latter included cases of gliosis, cerebritis and mesial temporal sclerosis. Immunohistochemistry for Bcl-x and GFAP was performed. Double immunofluorescent labeling using antibodies to both GFAP and Bcl-x was also carried out. Expression of Bcl-x closely follows that of GFAP with strong expression in both reactive astrocytes and astrocytomas. There is more focal expression in other gliomas. Immunostaining for Bcl-x is generally more intense and distinct, compared to that for GFAP. Expression of both GFAP and Bcl-x is more focal in oligodendrogliomas, with staining of mainly intervening astrocytic processes. Double immunolabelling confirms the coexpression of Bcl-x and GFAP in various gliomas and reactive brain conditions. As immunostaining for Bcl-x is generally more distinct and intense than that for GFAP, it may serve as a useful alternative to help highlight glial cells in selected diagnostic settings.