Cancer Keys

Key points

• Symptoms of a suspected cancer should be assessed independently from the ‘normal pregnancy’ signs, without the pregnancy affecting your judgement.  

• Encourage patients to be aware of the changes to their body.  

• If there are any concerns, discuss this with the patient and adopt a robust safety netting approach. 

• Be aware that the tumour marker CA125 is elevated during pregnancy and is unreliable.  

Cancer and pregnancy 

It is estimated that 1 in 1000 to 1 in 2000 pregnancies are affected by a cancer diagnosis. Although cancer in pregnancy is a rare event, cancer in pregnancy is becoming more common, as more women choose to become pregnant later in life and due to the increasing incidence of cancer risk factors such as obesity.  

The most common forms of cancer in pregnancy, are the same as those you would expect in women of childbearing age, such as breast cancer, melanoma, cervical cancer, thyroid cancer, leukaemia and lymphoma. Another rare but important group of cancers in pregnancy, are the cancers of the fertilised embryo known as Gestational Trophoblastic Tumours.  

See GatewayC’s cancer conversation on cancer and pregnancy to find out more. 

Pitfalls: cancer or pregnancy

Signs and symptoms of cancer can overlap with the physiological changes expected during pregnancy, which can delay both patient and clinician recognition of the symptoms.

A delay in the recognition and referral of cancer in pregnancy can lead to more advanced stages of disease, which can impact both foetal and maternal outcomes.

Concerns of the potential risks involved with the investigation of cancer in pregnancy, or the treatment involved, may also make clinicians less prone to immediately refer.

A variety of cancer treatments can be safely given in pregnancy, particularly from the second trimester onwards. Often treatment is delayed to the second trimester and an MDT approach is paramount when investigating and treating cancer in pregnancy.

Helpful hint: patient body awareness and seeing the symptoms in isolation

See the patient’s symptoms in isolation to the pregnancy and follow your usual referral pathways. Be aware that the serum tumour marker CA125 is elevated during pregnancy and unreliable; for suspected ovarian cancer, consider bypassing this test and referring to a specialist.

Body awareness can empower patients to notice concerning changes. For example, breast changes are common in pregnancy, however breast cancer is the most common malignancy noted in pregnancy and has an incidence of 1 in 3000. Therefore, patients should be encouraged to take note of the changes to their body and seek review if any concerns.

With patients who have previously been pregnant, it is important to ascertain if the symptoms they are experiencing differ from those of their previous pregnancies. If so, take these symptoms seriously.

Due to cancer symptom masking in pregnancy, it is important to adopt a robust safety netting plan and encourage patients to re-present if their symptoms do not improve as expected. You can consider pre-booking a follow-up appointment for the patient to provide further reassurance.

Practice take way: supporting patients and healthcare professionals

Mummy’s Star is a charity in the UK and Ireland dedicated to patients diagnosed with cancer during pregnancy or within the 12-month postnatal period and their families. They offer a variety of support and conduct events such as ‘cancer and pregnancy awareness week’, where they will educate patients on topics such as body awareness. Mummy’s star also offers useful learning resources for health care professionals.

Listen to GatewayC’s GPs Talk Cancer podcast episode: breast cancer and cancer in pregnancy- “it is safer to have chemotherapy than a glass of wine from the second trimester onwards”.