# Clear cell ovarian cancer

Source: https://onco.cc/cancers/clear-cell-ovarian-cancer/  
OnCo record `clear-cell-ovarian-cancer` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Clear cell ovarian cancer grows out of endometriosis, is usually caught early and cured by surgery, but when advanced it resists platinum chemotherapy. Its distinct genetics, with ARID1A and PIK3CA mutations, are the focus of targeted and immune approaches.

## Summary

Clear cell carcinoma is strongly associated with endometriosis and is commoner in East Asian women. About half carry ARID1A mutations and a third PIK3CA mutations; TP53 is usually wild-type. It presents as a large unilateral mass, often at stage I, with a raised risk of venous thromboembolism and hypercalcaemia. Surgery is curative for most early disease, with adjuvant carboplatin-paclitaxel for stage IC and above; advanced and recurrent disease respond poorly to chemotherapy and do not benefit from PARP inhibitors. Immune checkpoint inhibitors have produced responses in a minority, and trials target ARID1A loss (ATR and EZH2 inhibitors), PI3K and the hypoxia pathway.

## Fields

- Kind: Cancer
- Last checked: 2026-09-17
- Also known as: Ovarian clear cell carcinoma; OCCC
- Tags: subtype-page
- Group: gynaecological
- Burden: About one in ten ovarian cancers in Western countries and a quarter in Japan; most present at an early stage and are cured, but advanced disease responds poorly to chemotherapy and carries a worse outlook than high-grade serous cancer.
- Subtypes: Clear cell carcinoma arising in endometriosis; Stage I clear cell carcinoma (most cases); Advanced and recurrent clear cell carcinoma (chemoresistant)
- Biomarkers: ARID1A mutation (about 50 percent); PIK3CA mutation; HNF1B expression (diagnostic); Mismatch repair deficiency (a minority); Wild-type TP53

## Standard of care

- Early stage: Complete staging surgery; adjuvant carboplatin-paclitaxel for stage IC and above; observation may be considered for stage IA. ([Carboplatin](https://onco.cc/drugs/carboplatin/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/))
- Advanced or recurrent: Cytoreduction and platinum-based chemotherapy despite modest responses; clinical trials of immunotherapy and ARID1A-directed drugs are preferred where available. ([Pembrolizumab](https://onco.cc/drugs/pembrolizumab/), [ATR and CHK1 inhibitors](https://onco.cc/technologies/atr-chk1-inhibitors/))
- Supportive: Thromboprophylaxis awareness because of the high clot risk. ([Ovarian cancer](https://onco.cc/cancers/ovarian/))

## State of the art

- Recognition of clear cell cancer as a separate disease has ended its lumping into serous trials.
- ARID1A loss creates dependencies (ATR, EZH2, immune) now being exploited in dedicated trials.
- Early detection through endometriosis follow-up is under study in Japan.

## Open problems

- No effective treatment for platinum-resistant disease.
- Which early-stage patients can skip chemotherapy.
- Whether treating endometriosis reduces risk.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Clear-cell_ovarian_carcinoma
- Wikipedia: https://en.wikipedia.org/wiki/Clear-cell_ovarian_carcinoma

## Connected records

- drugs: [Carboplatin](https://onco.cc/drugs/carboplatin/), [Paclitaxel / nab-paclitaxel](https://onco.cc/drugs/paclitaxel/), [Pembrolizumab](https://onco.cc/drugs/pembrolizumab/)
- technologies: [ATR and CHK1 inhibitors](https://onco.cc/technologies/atr-chk1-inhibitors/)
- cancers: [Ovarian cancer](https://onco.cc/cancers/ovarian/)

---
JSON: https://onco.cc/api/v1/entities/clear-cell-ovarian-cancer.json