About Ovarian Cancer

Every three and a half hours, another woman is diagnosed with ovarian cancer in Canada. It is the leading cause of death from gynaecological malignancies and the fifth most common cause of cancer death overall. Doctors can effectively treat ovarian cancer with chemotherapy but relapse is almost inevitable when the disease is advanced. The statistics are grim: seven in ten women die within five years of diagnosis and the long-term disease-free survival rate for advanced ovarian cancer is only ten percent. Ovarian cancer typically strikes women in their fifth decade. Unlike many other cancers like breast cancer and prostate cancer, the outcomes for ovarian cancer have not significantly improved in 50 years and there have been no breakthroughs in ovarian cancer treatment in over a decade.

The most common ovarian cancers are of epithelial origin. Cancer occurs when epithelial cells in the fallopian tube or on the surface of the ovary are malignantly transformed. It is not known why this transformation occurs, though researchers have noted that this change is often accompanied by mutations in common cancer genes. Some individuals have an increased risk for ovarian cancer due to genetic factors including mutations in the breast cancer genes, BRCA1 and BRCA2. Anyone with a family history of ovarian cancer is recommended to see a genetic counselor regarding genetic testing.

Treatment of ovarian cancer focuses on first eliminating cancerous tissue through surgery followed by prevention of recurrence through chemotherapy. The need for chemotherapy after surgery depends on disease stage. Stage refers to how far the cancer has spread beyond the ovary. Stage I cancers are confined to the ovaries, Stage II cancers have spread to the pelvic organs (such as the uterus or fallopian tubes), Stage III cancers have spread to the abdominal organs or lymphatic system, and Stage IV cancers have spread to distant sites such as lung, liver, or brain. Ovarian cancers are also described by their grade. Grade refers to how abnormal the cancer looks under a microscope. Ovarian cancer is described on a continuum between low-grade and high-grade, with low-grade being the most similar to normal cells and high-grade being the most abnormal. The most common chemotherapies are taxanes and a platinum-based therapy such as carboplatin or cisplatin. Therapy typically begins two to six weeks after surgery and occurs in three week cycles. Unlike almost all other cancers, ovarian cancer does not typically spread through the bloodstream but instead is often contained within the abdominal cavity. Because of this, chemotherapy is sometimes administered directly to this cavity as opposed to intravenously.