The ovary is a ductless reproductive gland about the shape and size of an almond in which the female reproductive cells are produced. Females have a pair of ovaries, held by a membrane beside the uterus on each side of the lower abdomen. The ovaries are located on opposite sides of the uterus in the pelvic cavity and are attached to the uterus by the ovarian ligament
The ovaries play two central roles in the female reproductive system by acting as both glands and gonads.
- Acting as glands, the ovaries produce several female sex hormones including estrogens and progesterone.
- Estrogen controls the development of the mammary glands and uterus during puberty and stimulates the development of the uterine lining during the menstrual cycle.
- Progesterone acts on the uterus during pregnancy to allow the embryo to implant and develop in the womb.
- The ovary is needed in reproduction since it is responsible for producing the female reproductive cells, or ova.
Our body is made up of zillions of cells, and there is a continuous process where the cells of our body gets worn out after certain duration and gets replaced by new cells.
Cells in our body divide by a process called mitosis, where they replicate their DNA and divide into two halves. However, normal cells don’t divide infinitely, they stop dividing generally after 50 or 60 generations and commit apoptosis. This process is called senescence. Cancer cells don’t obey senescence, they are immortal and they keep dividing over and over again, giving rise to a tumor.
The National Cancer Institute defines cancer as “ a term used for diseases in which abnormal cells divide without control and invade nearby tissues”. Cancer is a collective term used for a number of diseases. There are multiple different types of cancer that show up in different parts of the body and every type of cancer works difffernetly, caused by different factors and demands unique prognosis.
Ovarian cancer refers to any cancerous growth that occurs in the ovary.
Types of Ovarian Cancer
There are many different types of ovarian tumors classified by the types of cells and tissue they originate from.
Epithelial ovarian cancers (EOC)
It is the most common type of ovarian cancer accounting to 90% of occurrences. Epithelial ovarian cancer means the cancer started in the surface layer covering the ovary. Epithelial cell tumors usually occur in women older than 50 years. These are sometimes referred to as carcinomas.
The four most common cell types of epithelial ovarian cancer are serous, mucinous, clear cell, and endometrioid. These cancers arise due to DNA changes in cells. The serous cell type is the most common variety.
The stroma is the supportive tissue of the ovary. They account for 5 – 8 % of ovary cancer. Stromal cell tumors are rare and may occur in women of any age, although certain tumors, such as androblastomas, may be more common in adolescence. These cancers come from various types of cells within the ovary. Stromal ovarian cancers include granulosa-stromal tumors and Sertoli-Leydig cell tumors.
Germ cell tumors
Germ cell tumors arise from the reproductive cells of the ovary and they accounts for 3 - 5 % of ovarian cancer. These tumors are uncommon and are seen most commonly in teens or young women. This type of tumor includes different categories: dysgerminomas, yolk sac tumors, embryonal carcinomas, polyembryomas, non-gestational choriocarcinomas, immature teratomas, and mixed germ cell tumors.
Ovarian Cancer Occurrence Rate in India
Ovarian cancer is among top three killers among adults in both rural and urban India. Though cancer incidence rates in India is lower as compared to western countries, but the rates are changing rapidly over recent decades. During the year 2002, it ranked third in frequency (4.1%) among all cancers in women.
In India, during the period 2004-2005, proportion of ovarian cancer varied from 1.7% to 8.7% of all female cancers in various urban and rural populations.
Ovarian cancer may not produce symptoms, particularly in the early stages. Some of the symptoms are mentioned below. However, they can be very subtle and vague, as well as very common.
- clothes suddenly not fitting
- leg swelling
- changes in bowel habits
- changes in bladder habits
- shortness of breath
- Persistent pelvic or abdominal pain
- Difficulty eating or feeling full quickly
- Increased abdominal size/persistent bloating
These symptoms, of course, occur with many different conditions and are not specific to cancer. Consulting the doctor and discussing the symptoms is important, especially if they occur frequently and persist for more than a few weeks.
The risk of developing Ovarian Cancer in the course of their lifetime for the general population of women is 2 %. However, some women have an increased risk of developing Ovarian Cancer. All women should be aware of the risk factors and of the symptoms of Ovarian Cancer.
"When you know the risk, you're empowered to make choices to reduce that risk. It’s not about scaring people; it’s about giving them the chance to be realistic."
There are a number of possible causes of Ovarian Cancer but these are not yet fully understood. The most important risk factors are age and a family history of ovarian or breast Cancer.
The risk of developing Ovarian Cancer increases with increasing age. Women over the age of 50 have a higher risk, and most cases of Ovarian Cancer occur in women who have already gone through the menopause. Although it is not common for younger women to get Ovarian Cancer, there are instances of Ovarian Cancer in pre-menopausal women. This is especially important if women have a family history of ovarian or breast Cancer.
About 85 % of Ovarian Cancer cases are 'sporadic'. This means they are one-offs, not inherited and close female relatives face no significant increase in their risk of developing the disease themselves.
The remaining 15 – 20 % of cases are believed to be caused by an inherited faulty gene, which is often the BRCA1 or BRCA2 gene.
Other Ovarian Cancer risk factors
The risk of Ovarian Cancer may also be linked to various activities, foods or physical traits, though these theories have no evident proofs to be backed by. Some such factors are cited below:
There is a slight increased risk of developing Ovarian Cancer for an obese person.
Use of Hormone Replacement Therapy (HRT):
Taking HRT increases a woman’s risk of developing Ovarian Cancer by 40 % compared to a woman who has never taken HRT. The lifetime risk of developing Ovarian Cancer is 2 %.
There is evidence to suggest that women with endometriosis have an increased risk of developing Ovarian Cancer.
Smoking can increase the risk of certain types of Ovarian Cancer. 3% of Ovarian Cancer seems to be linked to exposure to tobacco smoke.
Research has shown that diabetics have an increased risk of up to 25 % compared with non-diabetics of developing Ovarian Cancer. Additionally the risk may be slightly higher in diabetics who use insulin as opposed to diet or tablet controlled diabetics.
Women who have delivered at least one child, especially before age 30, are at a lower risk for developing the disease. The more children a woman has, the more her Ovarian Cancer risk declines. Women who breastfeed further reduce their risk.
Breast, colorectal or endometrial Cancer:
Women who’ve been diagnosed with one of these Cancers have a higher risk of developing Ovarian Cancer.
Some of the risk factors that might lead to ovarian cancer can be controlled by taking preventive measures. Some of the precautions are mentioned below:
Pregnancy and breastfeeding:
These combine to reduce the chance of developing ovarian cancer but they do not guarantee that one will not develop ovarian cancer. It is recognised that an increased number of ovulatory cycles raises the risk of ovarian cancer and conversely a decreased number of cycles reduces the risk.
Hysterectomy and/or having tubes tied:
Some women opt to have their fallopian tubes tied because they do not want any more children – this is called sterilisation. It is known to reduce ovarian cancer risk. Previously it was also thought that women who had had a hysterectomy (surgical removal of the womb) had a lower risk of developing ovarian cancer – however the benefits of this are now unclear and depend on factors such as the age at which surgery is done. Having a hysterectomy is known to reduce the risk of ovarian cancer.
If a woman takes birth control pills for more than 10 years, then her risk of ovarian cancer drops significantly. Tubal ligation has long been known to decrease the risk of ovarian cancer.
Ovarian cancer can be staged using TNM system.
T - The size of the tumor.
N - The spread to the lymph glands/lymph nodes (N).
M - The tumor has spread anywhere else in the body.
Stage I (T1-N0-M0): The tumor is limited to the ovaries or fallopian tubes.
- Stage IA (T1a-N0-M0): Only one ovary or fallopian tube is affected by the tumor. No cancer is detected on the surface of the ovary or fallopian tube and there are no malignant cells detected in fluid taken from the abdomen.
- Stage IB (T1b-N0-M0): Both ovaries (or fallopian tubes) are affected by the tumor. No cancer is detected in either the surface of the ovaries or fallopian tube, or in the fluid from the abdomen.
- Stage IC: The tumor is limited to one or both ovaries or fallopian tubes, with any of the following:
- Stage IC1: (T1C1-N0-M0):The ovary capsule is ruptured as a result of the surgery.
- Stage IC2: (T1C2-N0-M0): The ovary capsule ruptured before surgery, or there is a detectable tumour on the ovary or fallopian tube surface.
- Stage IC3: (T1C3-N0-M0): Cancerous cells are detected in the fluid taken from the abdomen.
Stage II (T2-N0-M0): The tumor is in one or both ovaries, or fallopian tubes, and has extended into the pelvis or the peritoneum (thin flexible sheet of transparent tissue that covers the organs inside your abdomen).
- Stage IIA (T2a-N0-M0): The cancer is also affecting the uterus and/or fallopian tubes
- Stage IIB (T2b-N0-M0): The cancer is affecting other organs in your pelvis
Stage III (T1/T2-N1-M0): The tumor is in one or both ovaries, or fallopian tubes, or the peritoneum, and has also extended to the lining of the pelvis and abdomen and/or nearby lymph nodes.
- Stage IIIA1 (T1/2-N1-M0): Very tiny cancer cells are detected in the lymph nodes in the lining of the abdomen. (Stage IIIA1(i) the tumour is up to 10 mm in dimension, and Stage IIIA1(ii) the tumour is more than 10 mm in greatest dimension).
- Stage IIIA2 (T3a2-N0/N1-M0): Very tiny cancer cells are detected above the pelvis, with or without the tumour detectable in the lymph nodes in the lining of the abdomen.
- Stage IIIB (T3b-N0/N1-M0): Small tumours (less than 2cm in diameter) are detectable beyond the pelvis, and the lymph nodes may or may not contain cancerous cells.
- Stage IIIC (T3c-N0/N1-M0): Small tumours (more than 2cm in diameter) are detected beyond the pelvis, including into the non-functional part of the liver and spleen and/or there is cancer.
Stage IV – A and B (any T–any N–M1): The cancer cells have spread to another organ such as the liver, the brain or the lungs.
Survival depends on many different factors. It depends on your individual condition, type of cancer subtype, treatment and level of fitness.
Epithelial Ovarian Cancer is the most deadly of the gynecologic cancers. Approximately 80% of patients will eventually die of the disease. However, survival in the short term is quite good. With the addition of IP chemotherapy, the survival of ovarian cancer has been significantly extended. According to recent studies, if a patient undergoes optimal debulking, followed by IP chemotherapy, then they have a greater than 50% chance to still be alive in six years. This is quite good compared to other advanced stage cancers. Even in the recurrent setting, epithelial Ovarian Cancer is often very sensitive to chemotherapy. The disease can often go in to complete remission (no detectable disease) many times. However, once it recurs, it is not curable and will continue to come back.
Germ cell and stromal tumors have a much better prognosis. They are often cured because they are more often detected at early stages
The survival rate is higher than 90 percent when the cancer is found early and treated right away. Doctors diagnose 15 percent of Ovarian Cancers at the earliest stages. Scientists are currently researching more improved and reliable ways to detect ovarian cancer early.
It’s much easier to treat ovarian cancer when diagnosed at an early stage. However, it’s not easy to detect. Ovaries are situated deep within the abdominal cavity, so it is unlikely to feel a tumor. There’s no routine diagnostic screening available for Ovarian Cancer. That’s why it’s so important to report unusual or persistent symptoms to your doctor.
If a woman has Ovarian Cancer symptoms, a strong family history, or a genetic predisposition such as a BRCA mutation, following tests are suggested:
- Blood Test - Though blood test is not the best test for diagnosing Ovarian Cancer, but it is helpful if a woman has symptoms of Ovarian Cancer or has already been diagnosed with ovarian cancer.
- Transvaginal Ultrasound - A transvaginal ultrasound is a test used to examine a woman’s reproductive organs and bladder.
- Pelvic Exam - A pelvic exam should be a part of a woman’s regular female health exam. A pelvic examination may reveal an Ovarian or abdominal mass. Ovarian cancer is rarely detected in a pelvic exam and usually it is detected if it is in an advanced stage.
Often vague symptoms eventually lead to a clinical diagnosis, or one based on suspicion generated by exams, laboratory tests, and imaging. However, an accurate diagnosis requires some of the tumor to be removed, either by biopsy (less often), or preferably, surgery to verify the diagnosis.
Various types of imaging studies can be used to diagnose this disease and lead to tissue sampling. Ultrasound and CT scans are the most commonly done studies. These often can give images that show masses in the abdomen and pelvis, fluid in the abdominal cavity (ascites), obstructions of the bowels or kidneys, or disease in the chest or liver. PET scans can be used, but often are not necessary if a CT scan is able to be performed.
The treatment depends on how far the cancer has spread. A team of doctors will determine a treatment plan depending on your situation. It will most likely include two or more of the following:
- surgery to stage the cancer and remove the tumor
- targeted therapy
- hormone therapy
Surgery is the main treatment for Ovarian Cancer. The goal of surgery is to remove the tumor, but a hysterectomy, or complete removal of the uterus is often necessary. It is often recommend removing both ovaries and fallopian tubes, nearby lymph nodes, and other pelvic tissue. Identifying all tumor locations is difficult.
Chemotherapy is typically given after surgery for all stages of Ovarian Cancer. Chemotherapy drugs are usually given intravenously, or administered directly into the abdominal cavity (intraperitoneal chemotherapy).
New therapies for Ovarian Cancer may be directed at blocking tumor growth by interfering with the formation of blood vessels to supply the tumor. The process of blood vessel formation is known as angiogenesis. The drug Avastin works by blocking angiogenesis, causing tumors to shrink or stop growing.
Having a symptoms associated with Ovarian Cancer may not necessarily indicate the presence of the disease. However, expert advice to rule out the possibility is prudent, making curative treatment possible. So, regular self examination and a physical examination at least once a year is recommended to facilitate early diagnosis of the disease.
Being aware of the symptoms, and any health issue that might indicate the presence of the disease needs to be examined thoroughly. Also, a few lab tests and regular tests can also sometime unveil the presence of the hideous disease.