The value and challenges of ovarian cancer diagnosis
Ovarian cancer is often called a “silent killer” because, in most women it causes either no symptoms or very vague symptoms such as bloating, abdominal pain, or feeling full quickly, that are ignored or mistaken for benign GI conditions.
Most general practitioners will see a woman with undiagnosed ovarian cancer only once every few years, making it an unlikely consideration in their diagnostic thinking. In the majority of women with ovarian cancer, by the time the diagnosis is made, the cancer is at a late stage: in these women, the 5 year survival rate is less than 30 per cent.
Up until now, current testing methods such as ultrasounds or blood tests (in which we measure two proteins, CA125 and HE4) have not been shown to effectively diagnose ovarian cancer in its early stages. Therefore, screening of healthy women for ovarian cancer by these methods has not been endorsed in medical guidelines.
A new approach that looks for small changes in CA125 associated with ovarian cancer in combination with ultrasound shows promise for early detection. The results of a large study of this method in over 200,000 women are expected to be announced later this year.
How can my blood tell me I have ovarian cancer?
Two proteins called CA125 (Cancer Antigen 125) and HE4 are often elevated in the blood of women with ovarian cancer. When a woman feels continuous pain in the lower part of her abdomen (in other words, in her pelvis), she goes through a first diagnosis which enables to identify a “pelvic mass”. In women who are diagnosed with a mass in their pelvis, measuring CA125 and HE4 in combination with other tests like ultrasound can help doctors decide whether the mass is likely to be cancer or a benign condition like an ovarian cyst.
Although blood tests can help doctors decide which women have a high risk of their mass being ovarian cancer, the diagnosis can only be made through a surgical examination of the ovaries.
If the tests suggest that the mass is likely to be ovarian cancer, then the patient can be referred to a specialist called a Gynecologic Oncologist (Gyn/Onc).
Gyn/Oncs have special training in the evaluation and surgical removal of ovarian cancer and studies have shown that women who are operated on by these specialists have better outcomes than those women who are operated on by non-Gyn/Oncs.
If the tests suggest that the mass is not cancer, then these women can safely undergo surgery by their Ob/Gyn close to home rather than having to travel long distances to a clinic specializing in ovarian cancer.