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Gynaecological cancer

Low-grade serous ovarian cancer

Low-grade serous ovarian cancer is an uncommon epithelial cancer that grows slowly and is often diagnosed in younger women than the high-grade type. Because its cells divide less quickly, standard chemotherapy tends to work less well, so surgery and other drug approaches matter more.

Last checked: 2026-10-03

Key facts

At a glance.

  • How common

    Macmillan describes low-grade serous disease as approximately 5% of cases in its guide to primary peritoneal cancer. It is a rare type.

  • Pace of growth

    Slow. Cells look much closer to normal than those in a high-grade cancer.

  • Who gets it

    It occurs across adult life but is more often found in younger women than high-grade serous disease.

  • Treatment emphasis

    Complete surgery whenever possible; chemotherapy is used but is often less effective than in the high-grade type, so hormone-blocking and targeted drugs are also considered.

  • Long course

    Many people live with it for years, with repeated treatment and monitoring rather than a single course.

A different disease from high-grade serous cancer

Both types are called serous, but they are best thought of as separate illnesses. The low-grade cancer arises through a different set of cell changes, so it does not carry the near-universal TP53 abnormality typical of the high-grade type, and BRCA variants are much less often involved.

It frequently grows alongside a serous borderline tumour, a growth made of abnormal cells that is not classed as cancer. Pathologists therefore look carefully at the sample to distinguish the two, and expert review of the slides is common.

How it presents and is found

Symptoms overlap with other ovarian cancers: persistent bloating, a swollen abdomen, pelvic or lower tummy pain, and changes in eating or in urinary habit. Because it grows slowly, some people have had mild symptoms for a long time before the cause is found, and some are diagnosed after a scan done for another reason.

The pathway is the same as for any suspected ovarian cancer. The GP arranges a CA125 test and ultrasound, a suspected cancer referral follows if needed, and the gynaecological cancer team arranges CT or MRI and a tissue diagnosis. CA125 can be normal or only modestly raised in this type, so imaging carries more weight.

Surgery as the foundation of treatment

Cancer Research UK states that surgery is one of the main treatments for cancer of the ovary, tube or peritoneum, with the aim of removing as much cancer as possible. For this slow-growing type, the amount of cancer left behind after the operation is considered particularly important, and referral to a centre experienced in complex abdominal surgery is common.

Early-stage disease in a younger woman may allow removal of one ovary and tube with the womb and the other ovary kept, after a team discussion of the risks. That fertility-sparing option is covered in a separate guide on this site.

Chemotherapy, hormone therapy and targeted drugs

Platinum chemotherapy, usually carboplatin with or without paclitaxel, is a standard drug for ovarian cancer, but cancers with slow-dividing cells respond less well than fast-growing ones. For that reason doctors may suggest a different order of treatment or other medicines.

The NHS notes that hormone-blocking treatment is used rarely in ovarian cancer overall. Low-grade serous tumours are one of the settings where it is discussed, since the cells often carry oestrogen receptors. Targeted medicines that act on cell-signalling pathways, and clinical trials designed for this rare type, may also be offered through a specialist centre.

Monitoring and living with a long-running cancer

Follow-up combines clinic reviews, imaging and sometimes CA125. When the cancer returns it is often slow to cause trouble, so treatment may be timed around symptoms and scan changes rather than started at the first sign. This approach is planned with the multidisciplinary team and should be explained clearly to you.

A clinical nurse specialist is the main contact between appointments. Mental health support, fertility advice and help with menopausal symptoms after surgery are all part of the care package, not extras.

Frequently asked

Questions people ask.

Quick, plain-English answers to the questions we hear most.

  • Is low-grade serous cancer less serious than high-grade?

    It grows more slowly, but it is still a cancer and can spread. Its slower pace and its weaker response to chemotherapy mean the treatment approach differs rather than being simply milder.

  • Why does chemotherapy work less well?

    Chemotherapy mostly targets cells that are dividing quickly. Low-grade cancer cells divide slowly, so a smaller share are affected at any given time.

  • Is it linked to BRCA?

    Much less than the high-grade type. Genetic testing may still be offered, and your team will advise on whether it is appropriate in your situation.

  • What is the link with borderline tumours?

    Serous borderline tumours and low-grade serous cancer are related and can be found side by side. Borderline tumours are made of abnormal cells that are not classed as cancer.

  • Can I keep my fertility?

    In selected early-stage cases, removing only part of the reproductive system may be possible. It depends on the stage, the pathology and a frank discussion of recurrence risk with your specialists.

  • Does hormone therapy replace surgery?

    No. It is generally used after surgery or when surgery is not possible, and the plan is made by the multidisciplinary team.

  • Will I be offered a clinical trial?

    Because the type is rare, research often takes place through specialist centres. Ask your team whether any trial suits your stage and treatment history.

  • How often will I be monitored?

    This is individual. Reviews are usually scheduled with imaging and blood tests, and you should have a named nurse to call about new symptoms in between.

Where this comes from

Sources and checking.

This guide is for information, not medical advice.

Your GP or consultant knows your history and can tell you which parts apply to you. If your symptoms are severe, rapidly worsening, or come with red-flag features, seek urgent medical care. Figures and availability change, so treat them as a guide and confirm with the provider.

Published 2026-10-03, next review 2027-10-03.

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