Anatomical facts: The ovaries are a pair of organs in the female reproductive system. They are located in the pelvis, one on each side of the uterus. Each ovary is about the size and shape of an almond. The ovaries have two functions: they produce eggs and the female hormone estrogen.
Ovarian cancer facts:
Ovarian cancer has the highest mortality rate of all gynecologic cancers. In the United States it ranks eighth in the number of new cases per year with 22,000, yet it ranks in fifth place in the number of deaths per year. The great majority of the 15,000 women who die from ovarian cancer each year could not be cured because their disease was not diagnosed early enough.
With early diagnosis, when the tumor has not spread beyond the ovary, this cancer has a 95% survival rate after five years. Unfortunately, the symptoms of early-stage ovarian cancer are very vague, for example, gas, bloating, indigestion, back or leg pains, and other symptoms that mimic gastrointestinal and other conditions. For this reason, more than 70% of patients are
diagnosed after their disease has already spread beyond the ovaries.
Causes of ovarian cancer:
Although the exact causes of ovarian cancer are not fully understood, researchers have identified several risk factors. The most significant risk factor is having a genetic mutation in the BRCAI or BRCA2 gene. These genetic mutations are more common among women of Ashkenazi Jewish ancestry and are also responsible for increased breast cancer risk. Other risk factors include age, obesity, early onset of menstruation and late onset of menopause, and never having children. Researchers are also studying the links between ovarian cancer and infertility, use of fertility drugs, use of estrogen replacement therapy, and use of talc, but so far none of these factors has been identified as a cause of ovarian cancer.
More than 90% of ovarian cancers are epithelial ovarian tumors; the remaining 10% are germ cell tumors and stromal tumors. Sometimes epithelial ovarian tumors develop outside of the ovaries, from the cells that line the pelvis or abdomen. These tumors are called primary peritoneal carcinoma and their symptoms and treatment are similar to ovarian epithelial
Early-stage ovarian cancer can be treated with surgery only. The surgery for ovarian cancer includes the removal of the ovaries, fallopian tubes, uterus, and other tissues or organs to which the disease has spread. The goal of the surgery is to remove as much of the cancer as possible. Women who have minimal tumor deposits after surgery generally experience longer remission periods and longer survival. Since more than 70% of patients are diagnosed
with advanced disease, most ovarian cancer patients will be treated with chemotherapy in addition to surgery. Ovarian cancer that has recurred can be treated with radiation therapy and hormonal therapy, in addition to more surgery and chemotherapy.
Treatment for ovarian cancer depends on many factors such as type and stage of ovarian cancer, the overall health of the patient and personal preferences.
Treatment can be done in the following ways:
- Radiation therapy
- Biological therapy
- Targeted therapy
- Hormone therapy
- Gene therapy
Surgery and chemotherapy are most often recommended for ovarian cancer.
Surgery is the mainstay treatment for ovarian cancer. Most women have surgery and chemotherapy or radiotherapy. Surgery can be done either by making an incision in the abdomen (process is called laparotomy) or by inserting a laparoscope, which is a tube like instrument with a camera and light at its end, through a small incision in the abdomen (process is called laparoscopy). Surgery is done to confirm whether the patient has cancer (biopsy), or for removal of the tumor in the ovary and as much as possible of cancer which has spread to other tissues (debulking).
Types of surgery:
Total hysterectomy: It refers to the surgical removal of the uterus
Bilateral salpingo-oophorectomy: It refers to the surgical removal of both ovaries and fallopian tubes.
Unilateral salpingo-oophorectomy: It refers to the surgical removal of an ovary and a fallopian tube.
Omentectomy: It refers to the surgical removal of the fatty tissue covering the intestines (omentum).
Removal of lymph nodes: Lymph nodes in the abdomen are removed for examination by a pathologist (biopsy).
For early stage ovarian cancer women who want to become mothers in the future, may opt for unilateral salpingo-oophorectomy and omentectomy.
Recovery after surgery may take a long time. Pain can be managed with the help of medicines. Several other complications may occur if the woman is still going through menopause.
Chemotherapy is the use of drugs for the treatment of cancer. When drugs are administered through a vein or by mouth, the chemotherapy is called systemic chemotherapy. Direct administration of drugs to the affected region is called regional chemotherapy.
Chemotherapy is a common treatment for women with ovarian cancer. The drugs can be administered through mouth (oral), vein (intravenous) or into the abdomen or peritoneal cavity (intraperitoneal). Drug administration in the peritoneal cavity is a form of regional chemotherapy. The other two are forms of systemic chemotherapy. Drugs are usually given in combination. Patients are allowed to rest after every cycle of treatment. The duration of rest depends on the kind of drugs and the dosage. Side effects also vary with the kinds of drugs used and their dosage.
Radiation therapy uses high energy radiation to destroy cancer cells. Radiation therapy can be given in two ways:
External radiation therapy: A beam of radiation from a machine outside the body is aimed at the affected region.
Internal radiation therapy or brachytherapy: Radioactive substance sealed in small devices is placed close to the tumor. Cancer cells are killed by the radiations emitted from the radioactive substances.
In some cases radioactive liquid is administered through a catherer into the abdomen. This form of radiation therapy is known as intraperitoneal radiation therapy.
Radiation therapy is usually given when the ovarian cancer is at an advanced stage. The purpose of radiation therapy for ovarian cancer is mainly palliative. Side effects are usually temporary.
Biological therapy is a kind of systemic therapy in which the body’s immune system is activated with the help of some substances. The activated immune system helps to kill the cancer cells in the body.
Targeted therapy refers to the use of certain drugs that inhibit the growth of cancer cells by blocking the effect of defective genes and proteins. Side effects are less when targeted therapy is used.
Hormone therapy is a treatment in which the activity or production of hormones is changed. Some hormones help in the growth and survival of some kinds of cancer cells. A substance which interferes with the interaction of the hormones with cancer cells thus helps to prevent the growth of cancer cells or kill them. Estrogen receptor positive cancers may be treated with a drug called tamoxifen. Unfortunately the results of hormone therapy for ovarian cancer are not very consistent, and more studies are required before they can be applied.
Gene therapy is a modern approach toward treatment of cancer. In this procedure, the damaged gene in the cancer cells is replaced by a normal gene. This is a new mode of treatment and is still in early days.
Clinical trials refer to those kinds of treatment which are not yet standardized. It is a part of research that aims to develop better strategies for the treatment of cancer. Patients may willingly participate in clinical trials, but cure is not guaranteed.
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This article was originally published on 7/12/2014 and last revision and update of it was 9/14/2015.