Overview
Ovarian Cancer: Ovarian cancer is a type of cancer that originates in the ovaries, the female reproductive organs responsible for producing eggs (ova) and the hormones estrogen and progesterone. Often, ovarian cancer remains undetected until it has spread within the pelvis and abdomen. This late detection, which has led to it being referred to as a “silent” disease, makes it a significant cause of cancer-related deaths among women. Treating ovarian cancer in its advanced stages is more challenging and often results in a fatal outcome.
Type of cancer
Types of Ovarian Cancer: Ovarian cancer is categorized based on the type of cell where the cancer originates. The three main types are:
1. Epithelial Ovarian Cancer: This is the most common type, accounting for about 85 to 90 percent of all ovarian cancers. It begins in the cells that cover the outer surface of the ovary. There are several subtypes of epithelial ovarian cancer, including serous, endometrioid, mucinous, and clear cell carcinomas. Epithelial ovarian cancer can spread to the lining and organs of the pelvis and abdomen, and sometimes to other parts of the body, such as the lungs and liver.
2. Germ Cell Ovarian Cancer: This rare type of ovarian cancer, accounting for less than 2 percent of all ovarian cancers, starts in the cells that produce eggs (ova) in the ovary. Germ cell ovarian cancer usually affects girls and young women up to their early 30s. The most common subtype of germ cell ovarian cancer is ovarian teratoma, which is often benign (non-cancerous). Other subtypes include dysgerminoma, yolk sac tumor, embryonal carcinoma, and choriocarcinoma.
3. Stromal Cell Ovarian Cancer: This rare type of ovarian cancer, accounting for about 5 percent of all ovarian cancers, starts in the cells that form the ovarian structural tissues and produce hormones, such as estrogen and progesterone. Stromal cell ovarian cancer can be benign or malignant (cancerous). The most common subtype of stromal cell ovarian cancer is granulosa cell tumor, which can occur at any age. Other subtypes include thecoma, fibroma, and Sertoli-Leydig cell tumor.
Each type of ovarian cancer has different characteristics, symptoms, risk factors, and treatments. The prognosis of ovarian cancer depends on many factors, such as the type, stage, and grade of the cancer, the response to treatment, and the overall health and age of the patient. In general, the earlier the cancer is detected and treated, the better the outcome.
Stage
Staging of Ovarian Cancer: The staging of ovarian cancer, as outlined by the FIGO staging system and the American Joint Committee on Cancer (AJCC), describes the extent of the cancer’s spread. Here is a detailed breakdown of each stage:
Stage I:
· Stage IA: Cancer is limited to one ovary, with no tumor on the ovarian surface and no malignant cells in the ascites or peritoneal washings.
· Stage IB: Cancer is limited to both ovaries, with no tumor on the surfaces of the ovaries and no malignant cells in the ascites or peritoneal washings.
· Stage IC: Cancer is present in one or both ovaries, with one or more of the following: tumor on the surface of one or both ovaries, capsules ruptured, or malignant cells in the ascites or peritoneal washings.
Stage II:
· Stage IIA: The cancer has extended to the fallopian tubes or uterus.
· Stage IIB: The cancer is present in other pelvic tissues.
· Stage IIC: The cancer has the same criteria as IIA or IIB, but with malignant cells in the ascites or peritoneal washings.
Stage III:
· Stage IIIA: While the cancer is technically in the abdomen, no cancer is visible in the abdomen to the naked eye, but microscopic cancer cells are found in the lining of the abdomen. There might also be cancer in the retroperitoneal or pelvic lymph nodes in this stage that is only visible microscopically.
· Stage IIIB: The cancer in the abdomen is visible but measures 2 cm or smaller.
· Stage IIIC: The cancer in the abdomen is larger than 2 cm, and/or there are cancer cells in the retroperitoneal or pelvic lymph nodes.
Stage IV:
· Stage IVA: Cancer cells are found in the fluid around the lungs (pleural fluid), with positive cytology for malignancy.
· Stage IVB: The cancer has spread to the inside of the spleen or liver (parenchymal metastasis) or to distant organs and sites such as the lungs, brain, lymph nodes outside of the abdominal cavity, the inner surface of the bowel, or other areas via the bloodstream or lymphatic system.
Each stage provides valuable information about the prognosis and guides the appropriate treatment route for ovarian cancer. Early stages have better prognoses and more treatment options compared to later stages, where the cancer has spread beyond the ovaries and more aggressive treatment are necessary.
Incidence Rates
Global Statistics on Ovarian Cancer: Ovarian cancer, while not as prevalent as other cancers such as breast, lung, or colorectal cancer, remains a significant cause of morbidity and mortality among women worldwide. This is largely due to its typically late stage at diagnosis.
The global incidence rate of ovarian cancer is estimated to be approximately 6.6 per 100,000 women per year, according to data from the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO).
In Asia, the incidence rates can vary widely due to diverse populations, lifestyle factors, healthcare systems, and the prevalence of known risk factors like BRCA gene mutations. For instance, the rates are relatively low in some parts of Asia such as East Asia but higher in South and West Asia. However, acquiring accurate incidence rates for specific regions within Asia requires access to regional cancer registries or global databases updated with the latest research findings and recorded incidences.
In every region, including Asia, these rates are influenced by various factors such as genetic predispositions, regional screening practices, protective factors like the widespread use of birth control and higher pregnancy rates, environmental factors, diet, and access to healthcare. Accurate, contemporary regional statistics are best obtained from local cancer registries and health department reports or international databases like the GLOBOCAN database managed by IARC.
Symptoms
Symptoms of Ovarian Cancer: The symptoms of ovarian cancer are often associated with more common, less serious conditions, making the disease difficult to detect. If you experience these symptoms and they’re new, persist for more than a few weeks, or you feel they’re significant, it’s crucial to see a doctor. The symptoms include:
1. Abdominal bloating or swelling: This is one of the most common symptoms of ovarian cancer, with around 72% of those with ovarian cancer reporting experiencing bloating.
2. Quickly feeling full when eating: Also known as early satiety, this symptom can be caused by the cancer itself or the buildup of fluid in the abdomen, a condition known as ascites.
3. Weight loss: Unexplained weight loss can be a symptom of ovarian cancer and many other types of cancer.
4. Discomfort in the pelvic area: Pain in the abdomen and pelvis is one of the most commonly reported symptoms among people with ovarian cancer.
5. Fatigue: Persistent tiredness that doesn’t improve with rest can be a symptom of ovarian cancer.
6. Back pain: While back pain is a common ailment, it can sometimes be a symptom of ovarian cancer.
7. Changes in bowel habits, such as constipation: Changes in bowel habits are often reported by women with ovarian cancer.
8. A frequent need to urinate: This can be due to pressure from the cancer or fluid buildup in the abdomen.
Remember, early detection of ovarian cancer can significantly improve the chances of successful treatment.
Cause
Risk Factors for Ovarian Cancer: The exact cause of ovarian cancer is unknown, but several factors can increase the risk of developing it:
1. Age: Ovarian cancer is more common in women over 50 years old, particularly those who have gone through menopause.
2. Family History: Having a close relative, such as a mother, sister, or daughter, who has had ovarian cancer, breast cancer, or colorectal cancer can increase the risk.
3. Genetic Mutations: Certain inherited gene mutations, such as BRCA1 and BRCA2, can increase the risk of ovarian cancer.
4. Hormone Therapy: Taking estrogen after menopause, especially for more than 10 years, can increase the risk.
5. Obesity: Being overweight or obese can increase the risk.
6. Fertility Treatment: Some studies suggest that using fertility drugs, such as clomiphene citrate, may increase the risk, especially if the treatment is unsuccessful or lasts for more than one year.
7. Endometriosis: This condition, where the tissue that normally lines the uterus grows outside the uterus, can increase the risk.
8. Smoking: Smoking can increase the risk of some types of ovarian cancer, such as mucinous ovarian cancer.
Conversely, certain factors may lower the risk of ovarian cancer:
1. Pregnancy and Breastfeeding: Having one or more full-term pregnancies, especially before the age of 26, can lower the risk. Breastfeeding may also have a protective effect.
2. Birth Control: Using oral contraceptives (birth control pills) can lower the risk. The longer the pills are used, the lower the risk.
3. Tubal Ligation or Hysterectomy: Having a tubal ligation (having the fallopian tubes tied) or a hysterectomy (having the uterus removed) can lower the risk. However, these surgeries should only be done for valid medical reasons, not solely for preventing ovarian cancer.
Risk factors
Diagnosis
Diagnosing ovarian cancer typically involves a combination of clinical evaluation, imaging, blood tests, and surgical procedures. Here are the common steps and tools used in the diagnosis of ovarian cancer:
Pelvic Examination: A physician may perform a manual pelvic exam to feel for abnormalities in the ovaries or uterus. However, early-stage ovarian tumors are often difficult to detect through a pelvic exam alone due to their location deep within the pelvis.
Imaging Tests:
Transvaginal ultrasound (TVUS): A probe is inserted into the vagina to obtain images of the reproductive organs and can help identify masses in the ovaries.
Computed tomography (CT) scans: These can provide detailed images of the abdomen and pelvis, looking for tumors and checking for the spread of the disease.
Magnetic resonance imaging (MRI): Though less common, MRI can be used for detailed images when further clarification is needed from ultrasound or CT findings.
Blood Tests:
Cancer Antigen 125 (CA-125) Test: Measures the level of CA-125, a protein that is often elevated in women with ovarian cancer. However, it can also be elevated with non-cancerous conditions, making it not entirely specific for ovarian cancer.
Other tumor markers: Such as HE4, alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), lactate dehydrogenase (LDH), and inhibin which can be measured depending on the suspected type of ovarian tumor.
Biopsy: The definitive diagnosis of ovarian cancer requires a tissue sample, often obtained during surgery. A pathologist will examine the tissue under a microscope to confirm the presence of cancer cells.
Laparotomy or Laparoscopy: These surgical procedures allow doctors to directly look at the ovaries and other abdominal organs and take tissue samples for biopsy.
Genetic Testing: For those with a family history of ovarian cancer or related cancers, genetic testing for mutations in genes like BRCA1 and BRCA2 may be recommended, which can influence the risk of ovarian cancer.
Due to the non-specific symptoms and the absence of effective screening tests for early detection, ovarian cancer is often diagnosed at a later stage. Once ovarian cancer is suspected or diagnosed, it is also staged to help determine the extent of disease spread, which is crucial for planning treatment.
Test
Treatment
The treatment of ovarian cancer depends on various factors, including the type, stage, and grade of the cancer, as well as the patient’s overall health and preferences. The primary treatments for ovarian cancer are surgery, chemotherapy, and targeted therapy. In some cases, radiation therapy or hormone therapy may also be used.
Surgery is often the primary treatment for most ovarian cancers. The objective of surgery is to remove as much of the cancer as possible. Depending on the extent of the cancer, the surgery may involve removing one or both ovaries, the fallopian tubes, the uterus, the omentum (a layer of fatty tissue in the abdomen), and nearby lymph nodes. If the cancer has spread to other organs, such as the bladder, colon, or liver, these may also be removed or partially removed.
Chemotherapy involves the use of drugs to kill cancer cells or inhibit their growth. It can be administered before or after surgery, or as the primary treatment if surgery is not possible. Chemotherapy can be given intravenously (through a vein) or intraperitoneally (directly into the abdomen). Sometimes, both methods are used. Side effects of chemotherapy can include hair loss, nausea, vomiting, fatigue, and an increased risk of infection.
Targeted therapy uses drugs that target specific features of cancer cells, such as gene mutations or proteins, that aid their growth and survival. Targeted therapy can be used alone or in combination with chemotherapy. Side effects can include skin rash, diarrhea, high blood pressure, and liver problems.
Radiation therapy, which involves the use of high-energy rays or particles to destroy cancer cells or shrink tumors, is not commonly used for ovarian cancer. However, it may be used in some cases, such as to alleviate pain or bleeding from cancer that has spread to other parts of the body. Side effects can include skin irritation, fatigue, nausea, and diarrhea.
Hormone therapy involves the use of drugs that block or lower the levels of hormones, such as estrogen and progesterone, that some ovarian cancers need to grow. This therapy is primarily used for stromal tumors, which are rare types of ovarian cancer that originate in the cells that produce hormones. Side effects can include hot flashes, vaginal dryness, mood changes, and weight gain.
Prognosis
Sure, let’s break it down:
Prognosis for Ovarian Cancer Patients: The prognosis, or estimated outcome, for ovarian cancer patients depends on various factors such as the type, stage, and grade of the cancer, the patient’s response to treatment, and their overall health and age. Generally, the prognosis is better when the cancer is detected and treated early.
Survival Rates: Survival rates express the percentage of people who live for a certain period of time after being diagnosed with cancer. These rates can be calculated for different time intervals (like one year, five years, or ten years) and for different stages and types of ovarian cancer.
According to the American Cancer Society:
· The 5-year relative survival rate for all types of ovarian cancer is 49.1 percent. This means that, on average, about 49 out of 100 women with ovarian cancer will survive for at least five years after diagnosis.
· However, this rate varies widely depending on the stage of the cancer. For instance, the 5-year relative survival rate for stage I ovarian cancer is about 92 percent, while the rate drops to about 17 percent for stage IV ovarian cancer.
Types of Ovarian Cancer: There are three main types of ovarian cancer, each starting in a different type of cell:
1. Epithelial Ovarian Cancer: This is the most common type, accounting for about 85 to 90 percent of all ovarian cancers.
2. Germ Cell Ovarian Cancer: This rare type, accounting for less than 2 percent of all ovarian cancers, starts in the cells that produce eggs in the ovary.
3. Stromal Cell Ovarian Cancer: This rare type, accounting for about 5 percent of all ovarian cancers, starts in the cells that form the ovarian structural tissues and produce hormones.
Each type of ovarian cancer has different characteristics, symptoms, risk factors, and treatments. The prognosis of ovarian cancer also depends on the subtype of the cancer. For example, some subtypes of epithelial ovarian cancer, such as serous and endometrioid carcinomas, have a better prognosis than others, such as mucinous and clear cell carcinomas.
The prognosis of ovarian cancer can change over time, depending on how the cancer responds to treatment and whether it recurs or spreads to other parts of the body. The prognosis is not a prediction of what will definitely happen, but a calculated guess based on statistics and experience. The prognosis can also vary from person to person, depending on their individual situation and preferences. Therefore, it is important to talk to your healthcare provider about your specific prognosis and what it means for you.
