Ovarian cancer is one of the common female reproductive cancers. It is the seventh most diagnosed cancer and is one of the leading causes of cancer-associated female mortality in the world. According to latest report of National Cancer Registry Program (NCRP), ovarian cancers rank third after uterine and cervical cancers in Indian women. Even though, ovarian cancer has a lower prevalence in comparison to the breast cancer, it has the worst prognosis and is three times more fatal than the breast cancer.
About ovarian cancer
Ovaries are a pair of oval-shaped female reproductive organs that produce and release eggs (ovum) for reproduction. It is responsible for the production of female hormones, such as estrogen and progesterone.
Ovarian cancer is a disease caused by abnormal growth and division of cells in the ovary. Previously, ovarian cancers are believed to begin only in the ovaries, but recent studies showed that ovarian cancer can also begin in the part of the fallopian tube near to an ovary and spread to the surface of the ovaries and beyond.
Types of ovarian cancer:
Ovaries are made of three kinds of cells and each type of these cells can develop into a different type of tumor:
- Epithelial cell tumors: Begin in the cells that cover the outer surface of the ovary and fallopian tubes, and account for 85 to 90 percent of ovarian cancers
- Germ cell tumors: Begin in the egg-producing cells and occur rarely
- Stromal cell tumors: Begin in the stroma, the tissue that hold the ovary together and surrounds the egg
Signs and symptoms of ovarian cancer
Ovarian cancers are often referred as “silent killers” as there are no reliable signs and symptoms in the early stages of this disease. Most of the early symptoms are similar to that of other conditions, such as irritable bowel syndrome (IBS). However, if ovarian cancers cause symptoms, it includes:
- Pelvic or abdominal pain
- Trouble eating or feeling full quickly
- Urinary urgency
Advanced stage symptoms include:
- Changes in bowel habits
- Pain during intercourse
- Lower back pain
- Unintentional weight loss or weight gain
- Abdominal swelling/ascites
Causes and Risk Factors
Cancers usually develop when some abnormal cells in the ovary begin to multiply in an uncontrollable rate creating a mass of abnormal cells. Some of these tumors are benign (non-cancerous), while others may be malignant (cancerous).
The following factors may increase the risk of ovarian cancer:
- Older age
- A family history of ovarian cancer
- A personal history of breast, uterine or colon cancer
- Use of hormone therapy after menopause
- Never having a full-term pregnancy
- Endometriosis, a condition where a tissue that normally lines the uterus is found outside the uterus
- Exposure to asbestos
Initially the signs and symptoms, medical history, and family history of the patient is reviewed. If something suspicious is found, a pelvic examination is done. In addition to the complete pelvic examination, the following tests are often recommended to detect ovarian cancers:
- TVUS (transvaginal ultrasound): It uses sound waves to locate a tumor in the ovary, and can give a clear idea of the size of the mass, as well as determine if it is a simple cyst, a complex cyst, or solid tumor.
- CA-125 blood test: It is a type of blood test that measures the amount of CA-125 protein in the blood. High levels of CA-125 usually indicate ovarian cancer.
However, for an accurate diagnosis, the following tests are recommended.
- Imaging tests: Tests such as a pelvic computerized tomography (CT) scan or magnetic resonance imaging (MRI) scans are recommended to examine the structures of the ovary. Positron emission tomography (PET) scan and chest x-ray can be done to determine whether ovarian cancer has spread to other parts of body, such as lungs.
- Laparoscopy: A laparoscope (a thin flexible tube with a mounted video camera) is passed into the pelvic region to view the ovaries and other pelvic organs. Also, surgical tools may be used to collect a sample tissue for biopsy.
- Biopsy: A biopsy involves removing a tissue sample and examining it in the laboratory.
- Blood test: A sample of blood is collected to determine the organ function and overall health of the person.
Stages of ovarian cancer
The cancer staging is done by TNM staging system. It provides detailed information about:
- Tumour (T): Whether the primary tumour has grown through the ovary wall
- Node (N): Whether the cancer has spread to the surrounding lymph nodes
- Metastasis (M): Whether the cancer has spread to distant parts of the body
Ovarian cancers can have the following stages:
- Stage I: The cancer is limited to the ovary/ovaries or fallopian tubes and has not spread to nearby lymph nodes.
- Stage II: The cancer is in one or both ovaries or fallopian tubes and has spread into the pelvis. It has not spread to nearby lymph nodes or distant parts of the body.
- Stage III: The cancer has spread outside of the pelvis into the abdomen and/or the retroperitoneal lymph nodes (lymph nodes at the back of the abdomen).
- Stage IV: The cancer has spread outside of the abdomen and pelvis or might have spread to distant parts of the body like bone, lung, or liver.
Treatment for ovarian cancer
The treatment is based on the stage of the ovarian cancer during the time of diagnosis and the general health of the patient. Treatment modalities for ovarian cancer include:
Surgery: It is the mainstay of treatment for ovarian cancer. The procedures may vary based on the type and stage of the ovarian cancer.
The common types of surgeries include:
- Oophorectomy: It involves the removal of one or both ovaries. If both the ovaries and fallopian tubes are removed, it is called bilateral salpingo-oophorectomy. It is usually recommended for germ cell tumors and stromal tumors that has not spread outside the ovary capsule (thick connective tissue layer).
- Cytoreduction/ Debulking surgery: It is recommended when the ovarian cancer has spread throughout the abdomen at the time of surgery. The main aim of this procedure is to completely remove the visible cancers larger than 1 cm. A debulking surgery involves removing a part of small intestine, spleen, gallbladder, as well as a part of the stomach, liver, and pancreas.
- Hysterectomy: It involves the surgical removal of uterus, cervix, fallopian tubes, ovaries, and surrounding tissues if the tumor has spread beyond the uterus.
- Lymphadenectomy: It involves the surgical removal of the lymph nodes when the cancer has spread through the lymph system.
Chemotherapy: It involves using drugs to destroy rapidly growing cancer cells in the body. These drugs interfere with the process of cell division and promote cancer cell death. For ovarian cancer, chemotherapy is administered as initial treatment for more advanced ovarian cancer that cannot be removed surgically.
Chemo drugs are injected into a vein (IV) or given orally. In some cases, it is inserted directly into the abdominal cavity called as intraperitoneal (IP) chemotherapy.
Radiation therapy: It involves delivering high-energy beams to destroy the cancer cells. It is usually recommended for advanced stage ovarian cancer. Radiation therapy is mostly combined with chemotherapy for effective results. For ovarian cancers, the radiation therapy is given either externally by using an external machine or internally by placing a radioactive substance near the tumour.
Targeted therapy: Targeted therapy involves the use of specific drugs to identify and destroy the cancer without causing much damage to the normal cells. For ovarian cancers, it is recommended to prevent the recurrence of cancer or for tumors that resists other treatments.
Hormone therapy: This therapy involves the use of hormones or hormone-blocking drugs to fight the cancer. It mostly helps treat the stromal cell tumors.
There is no known way to prevent ovarian cancers. However, research has shown that the following factors may help in the prevention of ovarian cancer:
- Taking birth control pills
- Longer breastfeeding
- Full-term pregnancies
- Undergoing surgical procedures like hysterectomy or a tubal ligation
The outlook generally depends on the type of the cancer and the stage of the cancer at diagnosis and individual factors, such as age, overall health, and how your body responds to the treatment. The survival rate is more than 90%, when the cancer is diagnosed in early stages.
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