Ovarian and uterine cancer are the fourth most common cancers in females in the UK in 2006, each making up 5% of cancers in females. By far the most common cancer is breast (31%) followed by colorectal (12%) and lung (11%) cancer. There are about 4,500 new cases each of endometrial and ovarian cancer in the UK each year with the incidence of endometrial cancer increasing. Worldwide, cervical cancer is the second most common cancer to affect women, with 3 out of every 4 of these cancers occurring in women in the developing countries.
The mortality from cancer and the morbidity from cancer treatment can be reduced by general population screening, early diagnosis and familial screening. With increased life expectancy in the UK the prevention of gynaecological cancers and early assessment and diagnosis of symptoms are becoming an increasingly important issue.
The UK Cervical Screening Programme has been highly successful in reducing the incidence and deaths from cervical cancer, mainly due to population coverage and the introduction of computerised call and recall in 1988. However, in 2007 there were 941 deaths from cervical cancer in the UK, and the failure to prevent this disease can lead to medical litigation.
Cervical screening will never be 100% accurate and false negative results have led to some laboratories being subject to considerable media interest. The development of liquid based cytology (LBC) involves taking the smear with a plastic device from which the cells wash off more readily than from a wooden spatula. Thin layer cytology based upon the liquid sample has the potential to reduce both the number of false negatives and unsatisfactory smears.
In order to ensure adequate sampling of the cervix, it is essential that the whole of the cervix is identified on speculum examination with a good light source. If the smear is taken in the correct fashion then the incidence of an inadequate sample will be around 2.9%. If the cervix cannot be identified then the patient should be referred to secondary care and sometimes to a colposcopy clinic depending on local arrangements.
The aim of the programme is prevention through the detection of cervical dysplasia rather than frank disease. Whilst the majority of women found to have an abnormal smear will not go on to develop cervical cancer, the loss of the opportunity to treat a patient with pre-invasive disease (usually by loop diathermy to the cervix), necessitating more radical treatment later such as hysterectomy or chemoradiotherapy, is likely to result in patient discontent. This is particularly likely where a patient has lost her ability to conceive.
Early stage cervical cancer may be asymptomatic and detected on smear or loop excision of the cervix. However the classical symptoms of irregular vaginal bleeding, especially post coital, requires urgent evaluation.
Most of these cancers occur in patients over the age of 50 and the most common presentation is postmenopausal bleeding, although 20 to 25% of women are premenopausal at diagnosis and approximately 5% are diagnosed in patients who are less than 40 years of age. The overall 5-year survival rate is high reflecting early presentation, and early referral for investigation is mandatory. About 10% of women with postmenopausal bleeding will be found to have endometrial cancer. A pelvic examination is essential to exclude a vulval or cervical lesion. The cervical smear history should also be checked.
Local arrangements for the management of patients where there is concern regarding the possibility of endometrial cancer varies. However, a transvaginal ultrasound scan for measurement of endometrial thickness and identification of ovarian masses is the investigation of choice. A thin endometrium has a high negative predictive value for endometrial cancer and in about 40% of cases it is possible to avoid hysteroscopy and curettage if the rest of the pelvic examination is normal. An endometrial biopsy can correctly diagnose endometrial cancer in around 80% of women.
Tamoxifen is an anti-hormone which is used for the adjuvant treatment of breast cancer in postmenopausal women. However, tamoxifen has a paradoxical proliferative effect on the endometrium and is associated in about one third of cases with endometrial pathology including hyperplasia polyps and cancer. This increased risk continues after cessation of the drug. No screening strategy has been found to be useful for these women and evaluation usually with hysteroscopy is required in women who have abnormal vaginal bleeding.
Some of the common causes of a pelvic mass are seen in the table (below). Although examination will help to ascertain the origin and aetiology of a mass, further investigations with imaging and laboratory tests are almost always necessary.
The following investigations should be considered:
1. In any woman of reproductive age, a urine or serum beta HCG test should be checked to rule out pregnancy.
2. Tumour markers. In a young patient who has been found to have a pelvic mass, germ cell tumour markers should be checked and these include alpha-fetoprotein (AFP), HCG, lactate dehydrogenase (LDH) and CA125 level. In perimenopausal and postmenopausal women, CA125 and CEA levels should be checked.
3. Ultrasound – transvaginal and transabdominal ultrasound scans are often the most efficient, accurate and least expensive imaging modality in the evaluation of a woman found to have a pelvic mass.
In perimenopausal and postmenopausal women ovarian cancer needs to be excluded and the Risk of Malignancy Index (RMI) can be helpful in triaging these patients. The RMI uses CA125 levels and ultrasound features and can be helpful to triage patients into low, moderate and high risk groups for ovarian cancer. Prompt referral into secondary care is required where there is the possibility of ovarian cancer.
There have been only modest improvements in the survival rate for patients with ovarian cancer and this is mainly due to the late presentation of the disease, with 70% of women having disease outside the pelvis at diagnosis.
Symptoms of abdominal bloating, increasing abdominal girth, change of bowel or bladder habit, abdominal or pelvic discomfort in a perimenopausal or postmenopausal woman may be the first symptoms of ovarian cancer and there should be a low threshold for arranging a CA125 and ultrasound scan in this group of patients.
Although most ovarian cancers are sporadic, about 5 to 10% arise because of a genetic predisposition. Mutations in the BRCA1 and BRCA2 genes account for the majority of inherited ovarian cancers. Most regional genetics centres provide a service for families with a history of cancer that seems to be in excess of what might be considered due to chance.
Women who have completed childbearing and are found to be at high risk of ovarian cancer should be offered bilateral salpingooophorectomy as this has been shown to significantly decrease the risk. Because ovarian cancer is often not diagnosed until the advanced stages, the opportunity of reducing this risk by prophylactic salpingooophorectomy should not be missed. In women who have not completed childbearing they should be counselled about screening using CA125 and ultrasound scanning although no definite conclusions on the effectiveness of this strategy are available. The contraceptive pill has been shown to decrease the risk of ovarian cancer by up to 50% in women at high risk.
The hereditary nonpolyposis colon syndrome is predominantly a colorectal cancer syndrome but is associated with an increased risk of endometrial and ovarian cancer. The role of surveillance of endometrial cancer remains unclear but referral to a regional genetics centre would be appropriate for counselling.
The cause and biology of the three most common gynaecological cancers in the UK is different and specific strategies for prevention and early diagnosis are required for each cancer site. Four key points to remember are:
- Good administration of the cervical screening programme will ensure prompt evaluation of abnormalities.
- Vague abdominal symptoms in a perior postmenopausal woman should be investigated to exclude ovarian cancer.
- Consider referral for genetic counselling if there seems to be a family history of cancer.
- Endometrial cancer is not confined to postmenopausal women and the diagnosis can usually be made on outpatient endometrial biopsy.
Dr David Farquharson is a consultant gynaecologist at the Edinburgh Royal Infirmary
COMMON CAUSES OF A PELVIC MASS
Ovary Benign/functional cyst
(including fallopian tube carcinoma)
Fallopian Tube Hydrosalpinx
Bowel Appendix abscess
Miscellaneous Urinary retention