Ovarian cancer is caused by abnormal and uncontrolled growth of cells from the tissues of the female ovaries. Each year approximately 225,484 new cases of ovarian cancer are diagnosed in women worldwide, with an estimated 140,153 dying of the disease each year.1 One of the greatest challenges in the management of ovarian cancer is that the majority of cases are not found at an early stage2when cure would be possible by surgery. Thus far, there exists no screening algorithm to achieve earlier diagnoses, which would make higher cure rates more feasible. Therefore, for the time being, more effective and tolerable treatments to achieve long-term remissions in the advanced-stages of the disease are warranted.
2. WHAT IS OVARIAN CANCER?
Ovarian cancer is an abnormal growth of tissue that develops into a heterogeneous group of malignancies in a woman's ovaries (female reproductive glands in which the ovar, or eggs, are formed). The disease often goes undetected until an advanced stage, as the malignancies often cause non-specific symptoms that mimic other conditions such as bladder disorders, which can lead to misdiagnosis or are attributed to non serious causes and cause delayed detection.
The ovaries contain three kinds of tissue: epithelial cells (covering the ovary), germ cells (inside the ovary) and stromal cells (these produce oestrogen and progesterone). All three can give rise to malignant ovarian tumours (i.e. epithelial ovarian cancer, germ cell tumours and sex cord stromal tumours). The most common type of ovarian cancer with around 90%4 forms in the epithelial ovary, known as epithelial ovarian cancer;3 . The epithelium is first trapped within the stroma to form inclusion cysts, which are then transformed into tumour cells. This process is thought to be hormonally driven.5 The two other most common types of ovarian cancer are germ cell tumours (5%) and stromal tumours (5%).4