Loss of ARID1A expression is associated with poor prognosis in patients with stage I/II clear cell carcinoma of the ovary

Background

Clear cell carcinoma of the ovary (CCC) has a poor prognosis because of its resistance to conventional platinum- or taxane-based chemotherapy. Consequently, there is a need to discover biomarkers for predicting the outcome of patients with CCC and develop novel treatment strategies for this disease. Recent studies have shown that somatic mutations in the AT-rich interactive domain 1A (SWI-like) gene (ARID1A) are the most common genetic changes in CCC. This gene is located in chromosome 1p36 and encodes a member of the switch/sucrose-nonfermentable (SWI/SNF) family protein BAF250a (ARID1A). Here, we investigated whether ARID1A could be a prognostic biomarker for this disease.

Methods

Paraffin-embedded specimens were collected from 220 Japanese patients with epithelial ovarian cancer, including 112 CCC and 108 high-grade serous adenocarcinoma of the ovary (HG-SAC). We analyzed the protein expression of ARID1A in these samples by immunohistochemical staining, and evaluated the association of these molecular parameters with clinical outcome.

Results

The loss of ARID1A expression was found in 39.3 % (44/112) of CCC, and strong expression of the protein was not observed. ARID1A protein was present mainly in the cell nuclei of the tumors; however, in tumors with HG-SAC, only 8 (7.4 %) tumors showed loss of ARID1A expression. The rate of absent expression of ARID1A in CCC tumors was significantly higher than in HG-SAC tumors (P 

Conclusions

The ARID1A protein may be a promising prognostic marker for FIGO stage I and II CCC.

Clinical trial identification

Legal entity responsible for the study

N/A

Funding

This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (17244120 to H. Itamochi).

Disclosure

All authors have declared no conflicts of interest.