This tumour is almost always an adenocarcinoma; the term adenocarcinoma refers to a cancer which arises from lining cells, this time those that line the uterine cavity. Occasionally there are other types of carcinoma that may arise from the endometrium and sometimes there may be a mix; squamous architecture can co-exist with the adenocarcinoma.
Incidence of uterine cancer
Uterine cancer is less common than cervical cancer with an incidence in the UK of 13 per 100,000 (3.5% of cancer in women). Established risk factors are nulliparity (no pregnancies), late menopause, obesity and prolonged exposure to oestrogens either as medical therapy or due to an oestrogen excess state. In this last situation, a period of endometrial hyperplasia (overgrowth – but at this stage non-malignant overdevelopment - of the lining of the womb) precedes the development of the cancer. The vast majority of women afflicted by this disease are past the menopause.
Causes of uterine cancer
The factors that predispose to endometrial cancer are not well worked out. However, the disease seems commoner in women who have experienced long periods of 'unopposed' oestrogen administration (e.g. long term oestrogen administration or granulosa cell tumours of the ovary). Such patients suffer from endometrial hyperplasia (an overgrowth of the uterine lining) and this is a predisposing causative factor for the development of uterine cancer. Pursuing the factor of 'unopposed' oestrogen exposure, nulliparous women and those with a long menstrual life (late menopause - after the age of 52) have a 2.5 times higher incidence of the disease. Other factors known to be associated with a higher incidence of the disease include obesity, diabetes mellitus, high blood pressure, endometrial hyperplasia (see above) and a family history of the disease or breast and/or colon cancer. The long term administration of the drug tamoxifen (used in the therapy of breast cancer) is associated with an increased incidence of endometrial cancer via promoting emndometrial hyperplasia; the risk is low circa 1 per 1000cases treated and in most incidences the beneficial effects in terms of breast cancer protection outweigh the risks associated with the drug's use on the uterine lining.
Symptoms of uterine cancer
The most common cause for the patient to present to the doctor is vaginal blood loss. This is an unexpected and worrying symptom for women past the menopause and a symptom that the doctor will always take seriously. In other instances, the patient complains of a vaginal discharge which may or may not be tinged with blood. In pre-menopausal women, the complaint may be of intermenstrual blood loss or discharge and a change to the pattern of the menses.
Treatment of uterine cancer
A total abdominal hysterectomy removal of the womb through an abdominal incision, with or without removal of the ovaries, is the treatment of choice for stage 1 and 2 disease, although a more extensive operation may be chosen for more advanced stage 2 cases and this may followed by a course of pelvic radiotherapy (external beam radiotherapy over five weeks).
With such therapy, for stage 1 disease, the five year survival rates are 73%, whereas the survival for those women presenting with stage 2 tumours is 56%. In stage 3 disease where the disease has spread beyond the ability of the surgeon to obtain a clear margin, then radical pelvic radiotherapy is chosen and a brachytherapy boost (see cancer of the cervix section for explanation of brachytherapy) may be given if it is deemed that the cervical and high vaginal regions are at especially high risk, given an individual patient’s situation. The five year survival rates for stage 3 cases are considerably less good than those of the first two stages and are around 30% survival at five years.