Comparative analysis of Rb1, P16 and ER as diagnostic, prognostic and potential targets for therapeutic agents in ovarian epithelial tumors: an immunohistochemical study of 130 ovarian carcinomas

A comprehensive immunohistochemical analysis of 26 markers in 250 cases of serous ovarian tumors

BACKGROUND

We examined a large cohort of serous tubo-ovarian tumors with 26 immunohistochemical markers, with the aim to assess their value for differential diagnosis and prognosis.

METHODS

Immunohistochemical analyses with 26 immunomarkers were performed on 250 primary tubo-ovarian tumors including 114 high grade serous carcinomas (HGSC), 97 low grade serous carcinomas (LGSC), and 39 serous borderline tumors (micropapillary variant, mSBT). The associations of overall positivity with clinicopathological characteristics were evaluated using the chi-squared test or Fisher's Exact test.

RESULTS

We found significantly different expression of p53, p16, ER, PR, PTEN, PAX2, Mammaglobin, RB1, Cyclin E1, stathmin, LMP2, L1CAM, CD44, and Ki67 in HGSCs compared to LGSCs. No significant differences were found between LGSC and mSBT. None of the other included markers (PAX8, ARID1A, HNF1B, Napsin A, CDX2, SATB2, MUC4, BRG1, AMACR, TTF1, BCOR, NTRK) showed any differences between the investigated serous tumors. Regarding the prognosis, only PR and stathmin showed a statistically significant prognostic meaning in LGSCs, with better overall survival (OS) and recurrence-free survival (RFS) in cases positive for PR, and worse outcome (RFS) for stathmin. None of the study markers showed prognostic significance in HGSCs.

CONCLUSION

We provided an extensive immunohistochemical analysis of serous ovarian/tubo-ovarian tumors. Although we found some differences in the expression of some markers in HGSCs compared to LGSCs, only p53, p16, and Ki67 seem to be useful in real diagnostic practice. We also suggested the best discriminative cut-off for Ki67 (10% of positive tumor cells) for distinguishing HGSC from LGSC. We found prognostic significance of PR and stathmin in LGSCs. Moreover, the high expression of stathmin could also be of predictive value in ovarian carcinomas as target-specific anti-stathmin effectors are potential therapeutic targets.

Higher expression of calcineurin predicts poor prognosis in unique subtype of ovarian cancer

BACKGROUND

The role of calcineurin/NFAT signaling in ovarian cancer has been unknown. NFAT was significantly overexpressed in ovarian cancer tissues and that overexpression of NFAT was significantly associated with metastasis and poor prognosis on clinical tissue level. To investigate whether NFAT upstream protein, calcineurin (CN), affects the prognosis in various histological subtype of ovarian cancer (OC).

METHODS

The association between CN and clinical features was analyzed in 50 OC patients treated from 2007 to 2012. CN expression was examined using immunohistochemistry. We observed the association of CN expression with the prognosis in these patients.

RESULTS

CN expression was significantly increased in later-stage tumor tissue of serous carcinoma compared with those with early-stage. The expression of CN positively correlated with the serum cancer antigen 125 (CA125) level in ovarian clear-cell carcinoma and the serum alpha-fetoprotein (AFP) level in papillary serous cystadenocarcinoma. Particularly, higher CN expression in tumor tissues significantly correlated with reduced overall survival among patients with serous carcinoma. In addition, the serum cancer antigen 72-4 (CA72-4) level, serum carcinoembryonic antigen (CEA) levels, pathological stage, lymph node metastasis, and chemotherapeutic resistance were identified as significant prognostic factors in ovarian clear-cell carcinoma, serous carcinoma, or papillary serous cystadenocarcinoma.

CONCLUSIONS

CN is upregulated in ovarian cancer tissues with later-stage and that the expression of CN, CA72-4, and CEA was remarkably associated with poor prognosis in unique subtype of ovarian cancer. CN levels may be investigated for use as a prognostic biomarker for risk assessment in unique subtype of OC patients.

Serous ovarian tumors: Immunohistochemical profiling as an aid to grading and understanding tumorigenesis

Background

The aim of this study was to evaluate the expression of p53, p16, Wilms tumor gene (WT1), and Mindbomb E3 Ubiquitin Protein Ligase 1 (MIB-1) index by immunohistochemical (IHC) staining in benign, low-grade, and high-grade serous ovarian tumors.

Methods

Forty-one cases of ovarian serous tumors were included in the study (benign serous tumor [n = 10], low-grade ovarian serous carcinoma [n = 8], and high-grade ovarian serous carcinoma [n = 23]). Expression of p53, p16, WT1, and MIB-1 by IHC was evaluated statistically with the grade of tumor. Semiquantitative scoring system for percentage (0-5) and intensity (1-3) of staining pattern was used to bring about objectivity.

Results

p53, p16, and WT1 showed significantly higher staining scores in ovarian serous carcinoma group than in the benign group (p < 0.05). However, p16 score was not significant in benign versus low-grade tumors. In the carcinoma group, the high-grade serous tumors showed significantly higher staining scores of p53, p16, and WT1 than the low-grade serous tumors (p < 0.05). Papillary serous tumors had comparatively lower p53 and WT1 scores for the same grade of tumor. MIB-1 scores were not significant.

Conclusion

p53, p16, and WT1 are helpful for the subtyping of serous ovarian tumors as low grade and high grade. WT1 is helpful in establishing primary ovarian serous tumors. The combination of moderate-to-high p53 and WT1 scores provides a robust way of confirming high-grade tumors.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.

Association of p16 expression with prognosis varies across ovarian carcinoma histotypes: an Ovarian Tumor Tissue Analysis consortium study

We aimed to validate the prognostic association of p16 expression in ovarian high-grade serous carcinomas (HGSC) and to explore it in other ovarian carcinoma histotypes. p16 protein expression was assessed by clinical-grade immunohistochemistry in 6525 ovarian carcinomas including 4334 HGSC using tissue microarrays from 24 studies participating in the Ovarian Tumor Tissue Analysis consortium. p16 expression patterns were interpreted as abnormal (either overexpression referred to as block expression or absence) or normal (heterogeneous). CDKN2A (which encodes p16) mRNA expression was also analyzed in a subset (n = 2280) mostly representing HGSC (n = 2010). Association of p16 expression with overall survival (OS) was determined within histotypes as was CDKN2A expression for HGSC only. p16 block expression was most frequent in HGSC (56%) but neither protein nor mRNA expression was associated with OS. However, relative to heterogeneous expression, block expression was associated with shorter OS in endometriosis-associated carcinomas, clear cell [hazard ratio (HR): 2.02, 95% confidence (CI) 1.47-2.77, p < 0.001] and endometrioid (HR: 1.88, 95% CI 1.30-2.75, p = 0.004), while absence was associated with shorter OS in low-grade serous carcinomas (HR: 2.95, 95% CI 1.61-5.38, p = 0.001). Absence was most frequent in mucinous carcinoma (50%), and was not associated with OS in this histotype. The prognostic value of p16 expression is histotype-specific and pattern dependent. We provide definitive evidence against an association of p16 expression with survival in ovarian HGSC as previously suggested. Block expression of p16 in clear cell and endometrioid carcinoma should be further validated as a prognostic marker, and absence in low-grade serous carcinoma justifies CDK4 inhibition.