# Low-grade serous ovarian cancer (LGSOC)

Source: https://onco.cc/terms/lgsoc/  
OnCo record `lgsoc` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Low-grade serous ovarian cancer is a slow-growing, RAS-driven type of ovarian cancer that resists chemotherapy but responds to hormone blockers and MEK-pathway drugs.

## Summary

About 5-10% of serous ovarian cancers; younger patients, KRAS/BRAF/NRAS mutations in ~30-50%, wild-type TP53, strong ER expression, low proliferation. Chemotherapy response rates are under 25%; endocrine therapy and MEK/RAF pathway inhibition (trametinib in GOG 281; avutometinib + defactinib, approved 2025) are the mainstays. Contrast with high-grade serous carcinoma.

## Fields

- Kind: Term
- Last checked: 2026-09-07

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Ovarian_cancer
- GOG 281/LOGS: trametinib versus standard of care in recurrent low-grade serous ovarian cancer (Lancet 2022): https://doi.org/10.1016/S0140-6736(21)02175-9

## Connected records

- cancers: [Ovarian cancer](https://onco.cc/cancers/ovarian/)
- targets: [KRAS](https://onco.cc/targets/kras/)
- drugs: [Avutometinib + defactinib](https://onco.cc/drugs/avutometinib-defactinib/), [Letrozole (and other aromatase inhibitors)](https://onco.cc/drugs/letrozole/)
- pathways: [Invasion: proteases, adhesion & the invasive front](https://onco.cc/pathways/invasion-ecm-degradation/), [RAS / RAF / MEK / ERK (MAPK)](https://onco.cc/pathways/ras-mapk/)
- trials: [RAMP 201](https://onco.cc/trials/ramp-201/)

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JSON: https://onco.cc/api/v1/entities/lgsoc.json