Ovarian Cancer Awareness Day takes place on 8 May every year and began in 2013. It came about to address the lack of awareness about this type of cancer, despite it holding the dubious distinction as the deadliest of all the gynaecological cancers. It is estimated that 1,580 women will be diagnosed with ovarian cancer in 2017, representing 2.7% of all female cancers. Likewise, it is estimated that 1,047 woman will die from ovarian cancer in 2017, more than from the combined total of cervical and uterine cancers, representing over half of all gynaecological cancer deaths and 5.1% of all female cancer deaths in 2017.
It is generally considered a disease of older, postmenopausal women, with 60% being diagnosed in women over 60 years of age. Younger women, however, are also affected, with 20% of women under 50 years and 10% under 40 years of age developing ovarian cancer. While incidence and mortality rates have been declining, the total number of new cases and deaths is increasing, largely as a consequence of our increasingly aging population.
Screening – unfortunately, no role
Our current understanding is that most ovarian cancers arise as precancerous lesions in the adjacent fallopian tube with subsequent “spread” to the ovary. Therefore, from its inception ovarian cancer has the potential for early intraperitoneal dissemination, or spread. With early stage disease, most patients are asymptomatic or have non-specific symptoms, including vague gastrointestinal upset, bloating, urgency and constipation. For these reasons early diagnosis and screening strategies have not been shown to be effective and are currently not recommended, particularly as large numbers of unnecessary surgeries are performed as a consequence.
What is Ovarian Cancer?
“Ovarian cancer” is not one disease but a wide array of biologically distinct malignancies. Ovarian cancer can arise from the germ or “egg cells” within the ovary, known as germ cell tumours. These cancers more commonly affect younger women and have an overall good prognosis. Cancers arising from the sex cords and stroma or the “substance” of the ovary are of low grade malignant potential and most cured by surgery alone. These mostly occur in older women.
Ovarian cancer also refers to cancers arising from the epithelium or skin covering the outside of the ovary. These develop from precancerous cells deposited by the adjacent fallopian tube. To complicate matters, these “epithelial ovarian cancers” comprise a variety of cell types including the more common serous cancers, as well as clear cell cancers, mucinous cancers and undifferentiated cancers. All of these ovarian cancers have different malignant and biological potential and response to treatment.
Risk Factors and Familial Predisposition
Most ovarian cancers are sporadic, arising in women without a hereditary predisposition. Factors that may increase the risk of developing ovarian cancer include increasing age, history of infertility, early onset of menstrual periods and late menopause. Other factors may decrease a woman’s risk of developing ovarian cancer, including oral contraception, pregnancy, breast feeding and tubal ligation.
However, the greatest risk of developing ovarian cancer is having a genetic predisposition, such as having the breast cancer gene (BRCA1 and BRCA1) transmitted through the family. Although these two gene mutations are not the only gene mutations that increase risk, they are the most common.
The natural history tends to be quite short, with progression to advanced stage within a short period of time. It is uncommon to have ovarian cancer diagnosed in an early stage (Stage I), most patients present with disseminated or stage III disease.
The cornerstone of treatment for suspected ovarian cancer is surgery. For early ovarian cancer, some women do not require additional treatments. For the vast majority of patients with ovarian cancer, surgery, known as cytoreductive or debulking surgery is the standard, where the goal is to remove all or as much cancer as possible. Scientific evidence strongly supports a superior outcome for patients whose surgery is performed by a Certified Gynaecological Oncologist and whose ongoing management is supervised by a Multi-Disciplinary Team. In some cases, chemotherapy may be required. This is often delivered intravenously, and occasionally via the intraperitoneal route.
Benefit of Participation in Clinical Trials
New Frontier: Peritonectomy and HIPEC*
By Professor Jonathan Carter and Dr Marcelo Nascimento, Chris O’Brien Lifehouse Gynaecological Oncology Group
*HIPEC involves delivery of a heated chemotherapy solution. The solution is heated to between 42-43°C. This is because cancer cells die at approximately 40°C, while normal cells die at approximately 44°C.