Serous and clear cell endometrial cancer (type 2) and molecular classification

Womb cancers are historically split into type 1 and type 2. Type 1, usually endometrioid, is linked to excess oestrogen and tends to grow slowly. Macmillan notes that about 3 out of 4 womb cancers are grade 1 or 2 endometrioid cancers. Type 2 includes serous carcinoma, clear cell carcinoma, carcinosarcoma, grade 3 endometrioid and mixed cancers, and these are always high grade.

Serous and clear cell cancers often arise in older people and in a thin, atrophic womb lining rather than after a long period of excess oestrogen. They can spread beyond the womb earlier, including through the abdomen, which explains why they are staged as thoroughly as ovarian cancer.

The NHS lists bleeding after the menopause as the leading symptom of womb cancer, with unusual heavy periods, bleeding between periods, discharge change, pelvic pain or a pelvic lump among others. Any bleeding after the menopause warrants assessment.

Tests include pelvic ultrasound, endometrial biopsy or hysteroscopy, and imaging such as MRI and CT to look for spread. Because these cancers can involve the peritoneum, a CT of chest, abdomen and pelvis is standard, and a blood marker may be checked in some centres.

Macmillan and Cancer Research UK both refer to molecular testing that groups womb cancers as MMRd, p53abn, POLE-mutated or NSMP. Pathology laboratories test for mismatch repair protein loss (MMRd), an abnormal p53 pattern (p53abn), a mutation in the POLE gene and, where none of these is present, the no specific molecular profile group (NSMP).

The groups carry different prognostic meaning. Tumours with a POLE mutation tend to do well, and treatment may be reduced. p53abn tumours are the most aggressive and are the group in which most serous cancers fall, so chemotherapy is the norm. MMRd tumours may respond to immunotherapy and prompt a check for Lynch syndrome. Details of how groups alter treatment are set by national guidelines, and your team explains your result.

Cancer Research UK describes surgery to remove the womb and cervix, usually with the ovaries and tubes, as the main treatment, with the extent depending on spread. Lymph nodes may be assessed, and for serous disease surgeons may also take samples from the omentum and abdominal lining.

After surgery, Cancer Research UK says that people with stage 3 or 4 disease or type 2 cancers fall into the group offered chemotherapy, with radiotherapy alongside, before or after, or chemotherapy alone. Drugs include paclitaxel and carboplatin. For recurrent cancer, chemotherapy may be given with immunotherapy, which the NHS lists as an option for advanced or recurrent disease.

Because these cancers are fast growing, recurrence is a real concern, particularly in the first couple of years. Outlook depends on stage, molecular group and how fully the cancer could be removed. Your specialist can tell you what applies to you, and palliative care teams can help with symptoms at any point.

Follow-up includes clinic reviews and imaging as indicated. After surgery, menopause symptoms if ovaries are removed, lymphoedema if nodes were taken and emotional recovery all need attention, and are covered in our guide to living after treatment.