The term "ovarian cancer" refers to a group of diseases that start in the ovaries or nearby organs such as the fallopian tubes and the peritoneum. One ovary is situated on either side of the uterus in the pelvis of women. The ovaries generate female hormones and eggs for sexual reproduction. Ovarian cancer risk may increase in some cases of mutations (changes in genes). The most frequent mutations that increase the risk of ovarian cancer are those in the breast cancer susceptibility genes 1 and 2 (BRCA1 and BRCA2) and those linked to Lynch syndrome. Different tumor forms and subtypes of ovarian cancer exist. Adenocarcinoma is the most prevalent tumor type, while serous adenocarcinoma is the most prevalent subtype.
Before the appearance of symptoms, ovarian cancer can grow and spread throughout the abdomen. Thus, early detection may be challenging. Symptoms of ovarian cancer may include:
Vaginal bleeding or vaginal discharge.
Abdominal or back pain.
Bloating or swelling in the abdomen.
Feeling full too quickly or having difficulty eating.
Discomfort or pressure in the pelvic area.
Changes in bowel habits, such as constipation.
Physical examination: During the physical examination, a rectovaginal examination with the empty bladder is performed to check the abdomen and pelvis region for any lumps or mass.
Blood tests: Blood tests may be performed to check the general health of patients including blood count, HCG levels, liver function tests, kidney function tests, alpha-fetoprotein levels, lactate dehydrogenase levels, inhibin, estrogen, and testosterone levels, and tumor markers [such as cancer antigen (CA) 125 and Carcinoembryonic antigen (CEA)]. These tumor markers are produced by the cancer cells.
Transvaginal ultrasonography: This test is more precise than a regular ultrasonography because it enables professionals to insert a special wand called a transducer into the vagina and close to the ovaries. To find growths and potential tumors, the device emits sound waves that bounce off the pelvic organs.
Histopathological examination of the biopsy sample: A biopsy is crucial for a definite diagnosis of ovarian cancer. A tiny tissue sample from the ovaries is removed during the surgery to check for the cancer cells. This can be accomplished using a needle that is guided by an ultrasonography or a CT scan. Another option is to use a laparoscope. If there is abdominal fluid, a sample can be tested for cancerous cells.
CT scan: A CT scan produces finely detailed images of the internal parts of the body using X-rays. CT scan is employed to evaluate the pelvis, abdomen, and lymph nodes around the ovaries and to check the spread of the cancer to other organs or tissues.
MRI: Magnetic resonance imaging (MRI) uses powerful magnetic fields and radio waves to provide precise images of the internal parts of the body. An MRI is used to check the pelvis, abdomen, and lymph nodes around the ovaries. Also, metastasis of cancer can be evaluated by MRI scan.
Laparoscopy: A small abdominal incision is made during a laparoscopic surgery to insert a thin tube (known as a laparoscope) into the abdominal cavity. To remove small fragments of tissue, surgical tools can be inserted through the laparoscope. A laparoscopy is performed to examine the abdomen for any unusual growths and to take tissue samples from the ovaries and other organs. It is also used to remove cysts or tiny tumors. To schedule surgery or other therapies, laparoscopy is also used to determine the stage of cancer
PET scan: A radioactive tracer is used in a PET scan to produce images of the various organs in the body. This examination may be useful in locating cancer cells that have spread to other parts of the body.
The course of treatment for ovarian cancer depends on the size, type, and location of ovarian cancer and also the spread of the cancer. Surgery, radiation therapy, and chemotherapy are the primary treatment methods. Targeted and hormonal therapies are additional treatment options.
In case of early-stage cancer that has not spread out of the ovaries, the following types of surgery may be performed:
Bilateral salpingo-oophorectomy (removal of both ovaries and the fallopian tubes)
Total abdominal hysterectomy (removal of the womb and the cervix)
If the cancer has spread out of the ovaries, additional surgery is required including colostomy (removing parts of the bowel).
High-energy X-rays or other particles are used in radiation therapy to eliminate cancer cells. It can be used to treat primary cancer as well as metastasis of cancer, either close to the primary tumor or in a distant organ, such as the brain or spinal cord. The two types of radiation therapy are brachytherapy (also known as internal radiation), which uses a device containing radioactive seeds or pellets to target radiation inside the body near the site of cancer, as opposed to the more common external beam radiation therapy, which uses a machine to concentrate radiation on the area of the body affected by cancer.
Chemotherapy is frequently a systemic therapy, which means that the drugs enter the bloodstream and reach almost every part of the body. Chemotherapy may be used to treat cancer that has metastasized, to decrease the size of extremely big tumors to facilitate surgery, or to eradicate very small cancer cell populations that may remain after surgery. Chemotherapy may be given intravenously or orally. In some circumstances, chemotherapy may also be administered directly into the abdominal cavity using a catheter (a thin tube) known as intraperitoneal chemotherapy.
Hormone therapy fights cancer by using hormones or hormone-blocking drugs. It includes:
Luteinizing hormone-releasing hormone (LHRH) agonists: LHRH agonists stop the synthesis of estrogen by the ovaries. These drugs are used to reduce estrogen levels in premenopausal women. Leuprolide (Lupron®) and goserelin (Zoladex®) are two examples of LHRH agonists. Every one to three months, these medications are administered. These medications might weaken bones if taken for a long period (years), sometimes resulting in osteoporosis.
Tamoxifen: It is frequently used to treat breast cancer. Tamoxifen acts as an anti-estrogen in many tissues in the body. Tamoxifen prevents any estrogens that may be present in the woman's body from promoting the formation of cancer cells.
Aromatase inhibitors: Aromatase inhibitors block the enzyme aromatase that converts other hormones into estrogen in post-menopausal women. They are only useful in women after menopause to lower estrogen levels. They consist of exemestane (Aromasin®), letrozole (Femara®), and anastrozole (Arimidex®). Capsules of these medications are consumed once a day.
Targeted therapy uses drugs to attack parts of cancer cells that differ from healthy cells. Targeted therapy includes angiogenesis inhibitors (Bevacizumab, Avastin), PARP [poly (ADP)-ribose polymerase] inhibitors (Olaparib, rucaparib, and niraparib), drugs that target folate receptor-alpha (Mirvetuximab soravtansine, antibody-drug conjugate), and drugs that target cells with NTRK gene changes [Larotrectinib (Vitrakvi) and Entrectinib (Rozlytrek)].
Immunotherapy uses drugs to help the body's immune system recognize and more efficiently eliminate cancer cells. Immunotherapy such as immune checkpoint inhibitors like Pembrolizumab (Keytruda), which targets the protein PD-1 on T-cells is recommended in patients with certain types of advanced ovarian cancer who have high levels of microsatellite instability (MSI) or changes in the MMR (DNA mismatch repair) genes. It is also given in patients with recurrent cancer after chemotherapy.
We still require the development of effective strategies to diagnose ovarian cancer at an earlier and more treatable stage. One of the major components of patient management for newly accessible treatment methods is shared decision-making that involves a discussion of the prognosis as well as advantages, safety profiles, symptom control, and symptom management.