Ovarian Cancer

NICE Clinical guideline [CG122] Ovarian cancer: recognition and initial management. Last updated: Apr 2026.

NICE guideline [NG12] Suspected cancer: recognition and referral. Last updated: Apr 2026.

British Gynaecological Cancer Society (BGCS) ovarian, tubal and primary peritoneal cancer guidelines: Recommendations for practice update 2024.

Article Last Updated:21/04/2026

Ovarian Cancer

Ovarian cancer is a heterogeneous group of malignancies arising from the ovary, fallopian tube, or peritoneum, with epithelial cancers being the most common type. It often presents late because early symptoms are vague and non-specific, making recognition of red flags and referral pathways especially important.

Updated UKMLA guide to ovarian cancer, based primarily on NICE guideline: types, risk factors, clinical features, referral criteria, diagnosis, and management.

Histology

There are 3 main histological categories of ovarian cancer:

Primary category	Sub-categories	Relevant features / description
Epithelial cancers (tubo-ovarian / primary peritoneal)	Serous carcinoma – most common (high-grade) Clear cell adenocarcinoma Endometrioid adenocarcinoma Mucinous adenocarcinoma	Most common category of ovarian cancer Most likely site of origin: distal fallopian tube
Germ cell tumours	Dysgerminoma Embryonal carcinoma Yolk sac tumour Non-gestational choriocarcinoma	Arises from reproductive cells Typically presents in young females (<30 y/o) Often secrete hormones and tumour markers, including hCG, AFP, LDH
Sex cord-stromal tumours	Granulosa cell tumours Sertoli-Leydig cell tumours	Tend to present in a younger age group Often characterised by symptoms related to excessive hormone production

Primary category

Sub-categories

Relevant features / description

Epithelial cancers (tubo-ovarian / primary peritoneal)

Serous carcinoma – most common (high-grade)
Clear cell adenocarcinoma
Endometrioid adenocarcinoma
Mucinous adenocarcinoma

Most common category of ovarian cancer

Most likely site of origin: distal fallopian tube

Germ cell tumours

Dysgerminoma
Embryonal carcinoma
Yolk sac tumour
Non-gestational choriocarcinoma

Arises from reproductive cells

Typically presents in young females (<30 y/o)

Often secrete hormones and tumour markers, including hCG, AFP, LDH

Sex cord-stromal tumours

Granulosa cell tumours
Sertoli-Leydig cell tumours

Tend to present in a younger age group

Often characterised by symptoms related to excessive hormone production

Causes and Risk Factors

Category	Risk factors
Hereditary and genetic	BRCA1 and BRCA2 mutations Lynch syndrome (HNPCC) Family history
Reproductive and hormonal factors	Factors that increase the number of lifetime ovulations:* Early menarche Late menopause Nulliparity Rationale: each ovulation causes repetitive trauma to the ovarian surface epithelium → cellular repair and proliferation → increase risk of DNA damage HRT also increases the risk – not through ovulation, but via direct hormonal effects on the ovarian and fallopian tube epithelial cells
Environmental factors	Smoking Asbestos

Clinical Features

Clinical features of ovarian cancer vary a lot depending on the histological category:

Ovarian cancer category	Clinical features and presentation
Epithelial cancer (tubo-ovarian / primary peritoneal)	Patients frequently present with vague, non-specific symptoms that are often misattributed to IBS, menopause, or endometriosis Symptoms: Bloating Abdominal discomfort / pain Early satiety Change in bowel or urinary habits (esp. ↑ urinary urgency and/or frequency) Back pain Tiredness Vaginal bleeding (although not as classically seen in endometrial cancer) Signs: Ascites Palpable abdominal / pelvic mass
Germ cell tumours	Typically present in young females (<30 y/o) Most common presenting symptom: abdominal pain + pelvic or abdominal mass ~10% presents with an acute abdomen (due to ovarian torsion / haemorrhage / rupture) Excess hCG secretion → false +ve pregnancy test, precocious puberty
Sex cord-stromal tumours	Typically presents in younger patients Abnormal vaginal bleeding – most common symptom Abdominal pain and mass Excess oestrogen secretion → Precocious puberty Irregular menstruation Endometrial hyperplasia Hirsutism Virilisation (developing male physical characteristics) – rare

Ovarian cancer category

Clinical features and presentation

Epithelial cancer (tubo-ovarian / primary peritoneal)

Patients frequently present with vague, non-specific symptoms that are often misattributed to IBS, menopause, or endometriosis

Symptoms:

Bloating
Abdominal discomfort / pain
Early satiety
Change in bowel or urinary habits (esp. ↑ urinary urgency and/or frequency)
Back pain
Tiredness
Vaginal bleeding (although not as classically seen in endometrial cancer)

Signs:

Ascites
Palpable abdominal / pelvic mass

Germ cell tumours

Typically present in young females (<30 y/o)

Most common presenting symptom: abdominal pain + pelvic or abdominal mass
~10% presents with an acute abdomen (due to ovarian torsion / haemorrhage / rupture)
Excess hCG secretion → false +ve pregnancy test, precocious puberty

Sex cord-stromal tumours

Typically presents in younger patients

Abnormal vaginal bleeding – most common symptom
Abdominal pain and mass
Excess oestrogen secretion →
- Precocious puberty
- Irregular menstruation
- Endometrial hyperplasia
- Hirsutism
- Virilisation (developing male physical characteristics) – rare

Ovarian cancer has a very poor prognosis and a high mortality rate, as it is clinically occult and is often diagnosed at an advanced stage. The 5-year overall survival rate for ovarian cancer in the UK is ~45%.

Red Flags and When to Refer (Primary Care)

The following applies to ANY individual with female reproductive organs (including women, trans men, and non-binary people).

If ovarian cancer is clinically suspected, the patient may require either 1) immediate suspected cancer pathway referral or 2) primary care investigations to guide further management, depending on the presenting red flags and clinical findings.

1. Immediate Suspected Cancer Pathway Referral

Suspected cancer pathway referral is indicated in the presence of:

Ascites, and/or
Pelvic or abdominal mass (which is not obviously uterine fibroids)

2. Primary Care Investigations

Step 1 – When to Investigate

3 scenarios that warrant primary care investigations for ovarian cancer:

Any of the following persistent / frequent symptoms (esp. >12 times per month and in those who are ≥50 y/o)

Persistent abdominal distension (often described as bloating)
Early satiety and/or loss of appetite
Pelvic / abdominal pain
↑ Urianry urgency and/or frequency

≥50 y/o with new-onset IBS-suggesting symptoms within the past 12 months

Rationale: IBS rarely present for the 1st time at this age

Consider carrying out tests in patient reporting ANY of the following:

Unexplained weight loss
Fatigue
Changes in bowel habit

Step 2 – Primary Care Investigations

The choice of initial test and subsequent actions depends on the patient’s age:

Patient’s age	Initial test	Subsequent steps
<40 y/o	Urgent ultrasound of the abdomen and pelvis CA125 is NOT an accurate indicator of ovarian cancer risk in younger patients	If the ultrasound scan suggests ovarian cancer → suspected cancer pathway referral
≥40 y/o	Measure serum CA125	If CA125 is elevated (above the age-specific threshold) → urgent ultrasound of the abdomen and pelvis If the ultrasound scan suggests ovarian cancer → suspected cancer pathway referral

Patient’s age

Initial test

Subsequent steps

<40 y/o

Urgent ultrasound of the abdomen and pelvis

CA125 is NOT an accurate indicator of ovarian cancer risk in younger patients

If the ultrasound scan suggests ovarian cancer → suspected cancer pathway referral

≥40 y/o

Measure serum CA125

If CA125 is elevated (above the age-specific threshold) → urgent ultrasound of the abdomen and pelvis

If the ultrasound scan suggests ovarian cancer → suspected cancer pathway referral

5 ultrasound findings that suggest an ovarian mass could be malignant:

Multilocular cysts (cysts with multiple chambers or compartments)
Solid areas within the lesion
Ascites
Bilateral lesions
Evidence of metastases

If the ultrasound is normal, or CA125 not meeting the age-specific threshold, NICE recommends:

Identify any other potential causes and investigate as appropriate, and
If no other cause is identified → advise to return to the GP if symptoms become more frequent and/or persistent

Investigation and Diagnosis (Secondary Care)

Step	Investigations
1	If not already completed in primary care, ensure the following are performed: Serum CA125 Ultrasound of the abdomen and pelvis For those <40 y/o, also measure additional tumour markers (AFP and beta-hCG) Purpose: to check for non-epithelial ovarian cancers Tumour markers are often elevated in germ cell tumours, which are more common in younger women
2	CT abdomen, pelvis +/- thorax to establish the extent of the cancer (to allow staging)
3	Pre-treatment tissue biopsy for histology is NOT routinely required for all patients Indicates if the primary treatment is cytotoxic chemotherapy → offer percutaneous image-guided biopsy before initiating chemotherapy If the primary management involves surgery, tissue biopsy can be obtained during the operation

Step

Investigations

If not already completed in primary care, ensure the following are performed:

Serum CA125
Ultrasound of the abdomen and pelvis

For those <40 y/o, also measure additional tumour markers (AFP and beta-hCG)

Purpose: to check for non-epithelial ovarian cancers
Tumour markers are often elevated in germ cell tumours, which are more common in younger women

CT abdomen, pelvis +/- thorax to establish the extent of the cancer (to allow staging)

Pre-treatment tissue biopsy for histology is NOT routinely required for all patients

Indicates if the primary treatment is cytotoxic chemotherapy → offer percutaneous image-guided biopsy before initiating chemotherapy
If the primary management involves surgery, tissue biopsy can be obtained during the operation

Do not use MRI routinely for assessing women with suspected ovarian cancer.

NICE recommends using the RMI I score to guide referral to specialist MDT

RMI I combines 3 pre-surgical investigation findings
- Ultrasound findings (1 point for each malignant-suggesting feature)
- Menopausal status (post-menopausal score higher)
- Serum CA125 level (in IU/mL)
Refer to specialist MDT if RMI I score ≥250

The RMI I score does NOT predict prognosis or survival of ovarian cancer; it simply helps determine the appropriate surgical team preoperatively. ^[Ref]

It is unlikely that one would be expected to memorise the full RMI I score calculation and referral thresholds. If anything, it is sufficient to be aware of the score components and their purpose.

It is worth noting that BGCS guidance differs from NICE CG122. BGCS advises that RMI should no longer be used as a triage tool in clinical practice because of its limited sensitivity and specificity, particularly in premenopausal women. Instead, BGCS strongly recommends replacing RMI with the newer IOTA-ADNEX risk model.

Management

Clinical stage	Corresponding FIGO stage	Management principles
Early-stage	Stage I (tumour limited to the ovaries or fallopian tubes)	Offer surgery to remove all visible disease and assess the extent of spread, which involves a midline laparotomy with: Total abdominal hysterectomy Bilateral salpingo-oophorectomy Infra-colic omentectomy Peritoneal biopsies Retroperitoneal lymph node assessment Adjuvant platinum-based chemotherapy (e.g. carboplatin) is only necessary for high-risk diseases (grade 3 or stage 1c) to prevent recurrence
Advanced-stage	Stage II-IV (tumour spread beyond the ovaries and fallopian tubes	There are 2 treatment paths to achieve complete resection of all macroscopic disease: If patient is fit for surgery + surgical resection of all macroscopic disease is possible → primary cytoreductive surgery, followed by adjuvant chemotherapy If patient is unfit for surgery or disease is too extensive to be surgically resected upfront → neoadjuvant chemotherapy, followed by interval cytoreductive surgery, followed by chemotherapy 1st line chemotherapy: paclitaxel + platinum-based compound (carboplatin or cisplatin)

Clinical stage

Corresponding FIGO stage

Management principles

Early-stage

Stage I (tumour limited to the ovaries or fallopian tubes)

Offer surgery to remove all visible disease and assess the extent of spread, which involves a midline laparotomy with:

Total abdominal hysterectomy
Bilateral salpingo-oophorectomy
Infra-colic omentectomy
Peritoneal biopsies
Retroperitoneal lymph node assessment

Adjuvant platinum-based chemotherapy (e.g. carboplatin) is only necessary for high-risk diseases (grade 3 or stage 1c) to prevent recurrence

Advanced-stage

Stage II-IV (tumour spread beyond the ovaries and fallopian tubes

There are 2 treatment paths to achieve complete resection of all macroscopic disease:

If patient is fit for surgery + surgical resection of all macroscopic disease is possible → primary cytoreductive surgery, followed by adjuvant chemotherapy
If patient is unfit for surgery or disease is too extensive to be surgically resected upfront → neoadjuvant chemotherapy, followed by interval cytoreductive surgery, followed by chemotherapy

1st line chemotherapy: paclitaxel + platinum-based compound (carboplatin or cisplatin)

In advanced stage 3 and 4 disease, targeted therapy is recommended after completion of chemotherapy. The choice of targeted therapies depends on biomarkers:

BRCA mutation +ve → olaparib (PARP inhibitor)
HRD +ve → olaparib + bevacizumab
BRCA mutation -ve → niraparib, rucaparib (PARP inhibitor)

Full FIGO Staging

The FIGO classification is included for reference and completeness.

Stage	Description
I	Tumour limited to the ovaries or fallopian tubes
IA	Tumour limited to one ovary (capsule intact) or fallopian tube; no tumour on ovarian or fallopian tube surface; no malignant cells in ascitic fluid or in peritoneal washings
IB	Tumour limited to one or both ovaries (capsule intact) or fallopian tubes; no tumour on the surface of ovary or fallopian tube; no malignant cells in ascitic fluid or in peritoneal washings
IC	Tumour limited to one or both ovaries or fallopian tubes, plus any of the following: IC1: Surgical spill IC2: Capsule ruptured before surgery or tumour on the surface of the ovary or fallopian tube IC3: Malignant cells in ascitic fluid or in peritoneal washings
II	Tumour involving one or both ovaries or fallopian tubes with pelvic extension (below pelvic brim) or peritoneal cancer
IIA	Extension and/or implants on the uterus, fallopian tubes, and/or ovaries
IIB	Extension and/or implants on other pelvic intraperitoneal tissues
III	Tumour involving one or both ovaries or fallopian tubes or peritoneal cancer with microscopically confirmed peritoneal metastases outside the pelvis and/or metastasis to the retroperitoneal lymph nodes
IIIA1	Positive retroperitoneal lymph nodes only (histologically proved): IIIA1(i): Metastasis $\leq$ 10 mm in largest dimension IIIA1(ii): Metastasis > 10 mm in largest dimension
IIIA2	Microscopic extrapelvic (beyond the pelvic brim) peritoneal involvement, with or without positive retroperitoneal lymph nodes
IIIB	Macroscopic peritoneal metastases that extend beyond the pelvis and that are $\leq$ 2 cm in largest dimension, with or without positive retroperitoneal lymph nodes
IIIC	Macroscopic peritoneal metastases that extend beyond the pelvis and are > 2 cm in largest dimension, with or without metastasis to retroperitoneal lymph nodes (includes extension of tumour to the capsule of the liver and spleen without parenchymal involvement of either organ)
IV	Distant metastases, excluding peritoneal metastases
IVA	Pleural effusion with positive cytology
IVB	Parenchymal metastasis and/or metastases to extra-abdominal organs (including inguinal lymph nodes and lymph nodes outside the abdominal cavity)

References

Hormone Replacement Therapy (HRT)

Irritable Bowel Syndrome (IBS)

Menopause and Premature Ovarian Insufficiency

Endometriosis

Share Your Feedback Below Cancel reply

You must be logged in to post a comment.

Ovarian Cancer

Ovarian Cancer

Histology

Causes and Risk Factors

Clinical Features

Red Flags and When to Refer (Primary Care)

1. Immediate Suspected Cancer Pathway Referral

2. Primary Care Investigations

Step 1 – When to Investigate

Step 2 – Primary Care Investigations

Investigation and Diagnosis (Secondary Care)

Management

Full FIGO Staging

References

Related Articles

Share Your Feedback Below Cancel reply

Be first to accessour QBank