Gynaecological Cancers Prevention, Screening, Diagnosis and Treatment

Dr. NGAN Yuen Sheung, Hextan

Honorary Consultant in Obstetrics & Gynaecology

Specialist in Gynaecological Oncology

Endometrial cancer, cervical cancer and ovarian cancer are amongst the ten most common gynaecological cancers in Hong Kong. While cervical cancer has the highest incidence rate in developing countries, the statistics also show that the incidence and mortality rates of endometrial cancer are on the rise worldwide. Ovarian cancer is considered most difficult to treat and has a relatively high mortality rate.

Screening for Gynaecological Cancers

Cervical cancers are closely associated with human papillomavirus (HPV). HPV infection is very common. While most people can get rid of HPV, a small number of high-risk HPV types may cause precancerous changes and cancer. As HPV can be sexually transmitted, screening is required for women with sexual activities.

Pap smear is most commonly used in Hong Kong to detect HPV. In some countries, pap smear has recently been replaced by HPV testing screening to detect the presence of DNA or RNA of high-risk HPV types in cervical cells. Those tested positive have a higher risk of developing precancerous conditions, even cancer.

Recent studies have focused on the relationship between positive HPV test results and precancerous conditions/cancers, using HPV16/18 genotyping for triage purposes. Those tested positive for HPV types 16 and 18 have a higher risk of developing precancerous conditions,and colposcopy is usually arranged. 

Screening should be repeated 6 months or a year later if one is tested positive for types other than HPV16 and 18 in HPV screening and negative in Pap test.  Colposcopy is required if Pap test shows abnormal results. Accurate patient triage facilitates case management by doctors and spare patients from undue concern. In the absence of standard methods, RNA testing or other markers are also used for triage purpose.

Endometrial cancer or ovarian cancer is less likely detected during regular check-ups. Large-scales studies showed that screening can detect ovarian cancer in post-menopausal women but cannot improve the survival rates. Therefore routine screening is not necessarily recommended for endometrial cancer and ovarian cancer.

Beware of Symptoms

Routine cervical screening is the most effective method to prevent cervical cancer. Even If you were tested normal in Pap test a year or a few months ago, you should still seek medical attention if early symptoms occur, such as abnormal bleeding between periods or after sex. For a prompt diagnosis, a biopsy is arranged as soon as cervical lesion is detected during gynaecological examination

Endometrial cancer mostly affects post-menopausal women at a median age of 56. The most common symptom is abnormal vaginal bleeding. Vabra aspiration and ultrasound are usually arranged, and in case of abnormal results, followed by hysteroscopy and biopsy for further investigation. The earlier the detection, the higher chance of recovery.

Early symptoms of ovarian cancer are less noticeable and often mistaken for other problems. Examples include bloating, abdominal discomfort after meals and mild abdominal pain. Past studies suggested that women should seek medical attention if mild symptoms occur for more than 12 times with a single month.

Ultrasound is commonly used to observe the solidity of ovarian cysts. Solid components may indicate malignancy. Ascites, bigger tumours or tumours on both sides of the ovaries may also occur in advanced ovarian cancer.  Other assessments include the use of CA125 tumour marker. Rather than confirm the diagnosis, this test can provide useful information for follow-up treatment.

If abnormality is found during ultrasound examination, CT scan or MRI scan is performed to detect metastasis. Doctors will advise the most appropriate treatment plan based on each patient’s condition.

Ovarian cancer is usually difficult to diagnose before surgery. To determine treatment option, surgery must first be carried out. The purposes of surgery are three-fold, i.e. pathological diagnosis of tumour, treatment (e.g. tumour removal) and cancer staging.

Cancer Staging and Treatment

Doctors used to carry out cervical cancer staging by clinical examination only. Now, can be performed with imaging or surgery. Treatment plan is devised based on cancer stage and other risk factors.

The mainstay of treatment of endometrial cancer is surgery. While its underlying causes are not fully known, the risk of developing endometrial cancer in higher in people who are at advanced age, obese or have never given birth before. Risk factors are first assessed by doctors, and surgery will be performed for cancer staging. Stage 1 endometrial cancer is usually found in the uterus only. As tumours less than 0.5cm in size are not shown on PET scan, surgery is required to remove the lymph nodes from the pelvis and the area next to the aorta for detection of metastasis and cancer staging. The presence of lymph node metastasis suggests stage 3 cancer, which requires chemotherapy or/and radiotherapy for treatment.

Even stage 1 ovarian cancer requires hysterectomy for cancer treatment.  Lymph nodes from the pelvis and the area next to the aorta are removed to perform omental and peritoneal biopsies. It is stage 2 when pelvic metastasis is confirmed, and requires chemotherapy for treatment. Stage 3 cancer is diagnosed upon detection of metastasis in the lymph nodes, omentum or abdominal cavity, and in the lungs or liver when in stage 4. Follow-up treatment is considered based on the presence of high risk factors in patients, e.g. cell differentiation. Stage 1 patients with risk factors may consider chemotherapy, which is required for most stage 2 to 4 patients.

Enhance Survival with the Combination of Targeted Therapy and Immunotherapy

Studies suggested that, when used in combination with chemotherapy, targeted therapy or immunotherapy is effective in extending progression-free survival. Related medications can be classified into three main categories:

• While it has not been proven to increase survival rate, angiogenic inhibitors can be used with chemotherapy and after chemotherapy to delay ovarian cancer recurrence. It is also suitable for patients with advanced cervical cancer or recurrent cancer, and is effective in extending lifespan by a few months.
• With promising clinical results in treatment of ovarian cancer, PARP inhibitors remain effective in patients showing good response to platinum-based chemotherapy when used with oral PARP inhibitors. Cancer recurrence can be delayed by about 3 years in patients with BRCA gene mutations, and several months in other patients.
• Patients with inhibitory receptor problems or microsatellite instability can use immunotherapy drugs such as PDL1 inhibitors to boost the immune system and destroy cancer cells.

Endometrial cancer may be hereditary. It can be triggered by DNA mismatch repair in Lynch syndrome patients, who can take immunotherapy drugs in advance stage or recurrence.

Looking forward, the future of cancer treatment lies in molecular targeted therapy. By way of tissue biopsy and genome sequencing, medications can be used as part of personalised treatment to effectively impede cancer growth.

Fertility-preserving Treatment

Treatments of most gynaecological cancers involve removal of uterus (hysterectomy).  For young patients with early stage cancer, conservative options are usually recommended to preserve fertility.

For stage 1A cervical cancer, loop electrosurgical excision procedure (LEEP) can be considered. Stage 1B patients (with a tumour less than 2cm in size) can undergo radical excision of the cervix and lymph nodes to preserve the uterus and ovaries.

If cancer is confirmed in only one ovary during cancer-staging surgery, patients with ovarian cancer may consider preserving the uterus and the unaffected ovary. 

A high dose of progesterone is prescribed to young patients with stage 1 endometrial cancer if MRI scans show that the cancer remains superficial and has not invaded the uterine muscle. Endometrial biopsy is also performed every 3 months for observation. Treatment is effective in over half of the patients, who can now undergo surgery after childbirth.