Ovarian cancer is a disease in which normal ovarian cells begin to grow in an uncontrolled, abnormal manner and produce tumors in one or both ovaries.
The female reproductive system consists of two ovaries, one on each side of the uterus. The size of the ovaries is about the size of an almond .These produce eggs (ova) as well as the female sex hormones estrogen and progesterone.
Ovarian cancer is the most common type of cancers in women. According to the research studies, ovarian cancer ranks fifth in cancer deaths among women. The chances of surviving ovarian cancer are better if the cancer is found early.
But because the disease is difficult to detect in its early stage, only about 20 percent of ovarian cancers are found before tumor growth has spread into adjacent tissues and organs beyond the ovaries. Most of the time, the disease has already advanced before it’s diagnosed.
Until recently, doctors thought that early-stage ovarian cancer rarely produced any symptoms. But new evidence has shown that most women may have signs and symptoms even in the early stages of the disease. Being aware of them may lead to earlier detection.
Ovarian cancer happens when cells that are not normal grow in one or both of your ovaries. The most common type of ovarian cancer is epithelial ovarian cancer. This cancer is often cured when it is caught early. But most of the time, the cancer has already spread by the time it is found.
Causes of Ovarian Cancer
As most of the other type of cancers the causes of ovarian cancer also remain unknown. Some researchers believe it has to do with the tissue-repair process that follows the monthly release of an egg through a tiny tear in an ovarian follicle (ovulation) during a woman’s reproductive years.
The formation and division of new cells at the rupture site may set up a situation in which genetic errors occur. Others propose that the increased hormone levels before and during ovulation may stimulate the growth of abnormal cells.
Three basic types of ovarian tumors exist, designated by where they form in the ovary. They include:
- Epithelial tumors: This form of ovarian cancer generally occurs in postmenopausal women. About 85 percent to 90 percent of ovarian cancers develop in the epithelium, the thin layer of tissue that covers the ovaries.
- Germ cell tumors: These tumors occur in the egg-producing cells of the ovary and generally occur in younger women.
- Stromal tumors: These tumors develop in the estrogen- and progesterone-producing tissue that holds the ovary together.
The exact causes of ovarian cancer are not clear. Some women who have it also have a family history of cancer and some do not.
Some women are more likely than others to get this rare cancer. They include women who are past menopause, who have never been pregnant, or who have never used birth control hormones.
Ovarian Cancer Stage
An exploratory laparotomy is done to the patients to determine the stage of the disease. The stage of the disease tells how far ovarian cancer has spread. During exploratory laparotomy, the physician (usually a gynecologic oncologist) makes an incision through the abdomen to the ovaries.
If cancer is detected, the physician removes as much of the tumor as possible. The extent of surgery depends on the type of cancer and how far it has spread. In some cases, one ovary is removed in a procedure called unilateral oophorectomy. Usually, the physician removes ovaries, the uterus, the fallopian tubes, and the omentum (fatty tissue that covers the bowels).
A biopsy (sample of tissue for microscopic evaluation) of pelvic and abdominal lymph nodes (small glands that filter out infectious organisms) may be performed. Finally, the abdominal cavity is “washed” with fluid that is then collected and examined under a microscope for cancer cells (called peritoneal lavage).
To stage the cancer, the physician reviews the histopathology report from the samples obtained during laparotomy, as well as results from needle biopsy, blood tests, imaging studies, or other tests.
Staging provides an estimate of disease-free survival, overall survival, and the risk for recurrence or relapse. Staging also helps the physician and patient to choose appropriate treatment(s).
There are four distinct ovarian cancer stage apart from the recurrent stage. They are as follows:
- Stage I: In this stage the Ovarian cancer is confined to one or both ovaries
- Stage II: In this stage the Ovarian cancer has spread to pelvic organs (e.g., uterus, fallopian tubes), but has not spread to abdominal organs
- Stage III: Ovarian cancer that has spread to abdominal organs (e.g., abdominal lymph nodes, liver, bowel).
- Stage IV: Ovarian cancer that has spread outside to distant sites (e.g., lung, brain, lymph nodes in the neck).
- Recurrent: This is the most advanced stage where the Ovarian cancer has recurred (come back) even though the patient has completed treatment.
Once ovarian cancer is assigned a stage, the classification does not change, even if the cancer recurs or metastasizes to other sites within the body.
Ovarian Cancer Symptoms or Signs of Ovarian Cancer
Ovarian cancer symptoms or signs of ovarian cancer are nonspecific and mimic those of many other more common conditions, including digestive and bladder disorders. It isn’t unusual for a woman with ovarian cancer to be diagnosed with another condition before finally learning she has cancer.
The key seems to be persistent or worsening signs and symptoms. With most digestive disorders, symptoms tend to come and go, or they occur in certain situations or after eating certain foods. With ovarian cancer, there’s typically little fluctuation were the symptoms are constant and gradually worsen.
Ovarian cancer does not usually cause symptoms at first. But most women do have some symptoms in the 6 to 12 months before ovarian cancer is found. The most common symptoms are pain or swelling in the belly and gas. Other symptoms are diarrhea or constipation, or an upset stomach.
But these symptoms are so general that they are more likely to be blamed on a number of other causes. Most of the time, the cancer has already spread by the time it is found.
Later stage symptoms result from the tumor growing in the pelvis. They can include:
- Abnormal vaginal bleeding in women after the menopause
- Pressure or bloating , fullness, swelling in the abdomen
- lower abdominal pain or low back pain
- irregular periods
- swollen abdomen
- pain during intercourse(dyspareunia)
- passing urine more often than usual
- Urinary urgency
- Constant and progressive changes in bowel or bladder patterns
- diarrhea or constipation
- Persistent digestive problems
- Ongoing excessive fatigue
- Pelvic discomfort or pain
- Persistent indigestion, gas or nausea
- Changes in bladder habits, including a frequent need to urinate
- Loss of appetite
- Unexplained weight loss or gain
- Increased abdominal girth or clothes fitting tighter around the waist
- A persistent lack of energy
If the cancer has spread into the abdomen, fluid can build up causing further swelling. Other symptoms at this stage can include feeling or being sick, tiredness, loss of appetite and shortness of breath.
Rarely, ovarian cancers secrete hormones that can cause bleeding of the lining of the uterus, breast enlargement or growth of facial hair.
Ovarian Cancer Treatment
The choice of ovarian cancer treatment and the long-term outcome (prognosis) for women who have ovarian cancer depends on the type and stage of cancer.
Your age, overall health, quality of life, and desire to have children (preserve fertility) must also be considered.
Surgery is done to confirm and treat cancer. Removal of all cancerous tissue and taking biopsies to check for the spread of cancer (surgical staging) is important for diagnosis and treatment because the amount of cancer remaining (residual cancer) after the initial surgery may affect the outcome.
The goal of the initial surgery is to remove all visible cancer. The type of surgery one needs depends on the stage of the cancer and if the patient wants to be able to have children after having the surgery.
If the patient has early-stage (stage I and low-grade [grade 1]) cancer and wishes to have children in future, then the surgery may include:
- Removal of the cancerous ovary and fallopian tube.
- A biopsy of the other ovary.
- Removal of fatty tissue (omentum) that is attached to some of the abdominal organs.
- Removal of lymph nodes in the pelvis and near the large blood vessel (aorta) in the belly.
- Biopsies of other tissues and peritoneal fluids (peritoneal washings) from the belly to find cancer cells.
By this initial surgery the uterus and the healthy ovary will remain, so it may be possible for the patient to become pregnant.
If the patient has more advanced stage (stage II, III, or IV) of cancer or stage I and do not want to have children, then the surgery may include:
- A hysterectomy is done which removes the uterus, and a salpingo-oophorectomy, which removes the ovaries and fallopian tubes.
- Collection of peritoneal fluid.
- Removal of pelvic and aortic lymph nodes (lymph node dissection).
- Removal of fatty tissue (omentum).
- Removal of as much cancerous tissue as possible.
- Biopsies of any tissue that may be cancerous.
Because this surgery removes all the reproductive organs, the person will not be able to become pregnant after having it.
Chemotherapy, which uses medicines to kill cancer cells, is recommended after surgery for most stages of ovarian cancer. Recent studies show that the addition of chemotherapy after surgery improves the outcome for some early-stage ovarian cancer. Chemotherapy is also recommended for all other stages of ovarian cancer.
This chemotherapy uses drugs designed to kill any remaining cancer cells. The initial regimen for ovarian cancer includes the combination of carboplatin (Paraplatin) and paclitaxel (Taxol) injected into the bloodstream (intravenous administration).
Studies have also shown that the combination results in longer survival, compared with that of previously used chemotherapy drugs and combinations.
A more intensive regimen has recently been shown to improve survival in women with advanced ovarian cancer by combining standard intravenous chemotherapy with chemotherapy injected directly into the abdominal cavity through a catheter placed at the time of the initial operation. This intra-abdominal infusion exposes hard-to-reach cancer cells to higher levels of chemotherapy than can be reached intravenously.
This treatment typically involves six rounds of both intravenous and abdominal chemotherapy. Side effects including abdominal pain, nausea, vomiting and infection may leave many women unable to complete a full course of treatment or others to forego treatment entirely. But even an incomplete course of this treatment may help women live longer.
Ovarian Cancer Prognosis and Survival Rate
Prognosis by stage
As with many other types of cancer, the outcome depends on how advanced the cancer is when it is diagnosed. In other words, the ovarian cancer prognosis and survival rate depends on the stage of the cancer.
Of all those women diagnosed with cancer of the ovary, between 4 and 5 out of 10 women (40 – 50%) will be alive for about 5 years after diagnosis.
- Stage 1: Very few clinical trials have been done with stage 1 ovarian cancer. So finding out the statistics on long term survival rates is quite difficult. But figures that are available suggest that about 9 out of 10 women diagnosed with stage IA and IB ovarian cancer will be alive for 5 years later. This is a general figure and individual situations do vary.
- Stage 2: 60 to 70% women diagnosed with stage 2 ovarian cancer will be alive for 5 years later.
- Stage 3: The survival statistics fall with these more advanced stages of ovarian cancer. 15 – 35% will live at least 5 years after their diagnosis. There is a wide range because the figures vary depending on how far the cancer has spread into the upper abdomen.
- Stage 4: As understood the survival statistics are lower for stage 4 ovarian cancers. The statistics for stage 4 vary quite a bit between reports. This is because this stage covers a lot of different situations. It means the cancer has spread, but it will have different effects depending on where it has spread. Between 5%-14% women with stage 4 ovarian cancer will live for at least 5 years. Doctors generally think a patient is doing well if they are alive for 2 years after being diagnosed with ovarian cancer that has spread.
The statistics may vary depending on general health, age or the type of tumor the patient has.