Learn more about ovarian tumors

The ovaries are important reproductive organs for women. Each woman usually has two ovaries, located on either side of the pelvic cavity. Ovarian cancer (also known as ovarian and peritoneal cancer), a silent killer for women, is more commonly referred to as ovarian tumors in the medical field. It can generally be divided into three types, referring to abnormal cell proliferation or malignant tumors in the ovarian tissue or epidermis.

According to data from the Hong Kong Cancer Registry, there were 654 new cases of ovarian and peritoneal cancer in 2021, making it one of the top ten cancers causing death among women in Hong Kong, with 236 deaths. Generally, early-stage ovarian tumors smaller than 4 cm do not present obvious symptoms and are mostly detected through ovarian tumor screening. However, when ovarian tumors reach a medium size of 4 to 8 cm, patients will experience significant abdominal discomfort such as bloating and indigestion. At this stage, patients often mistakenly believe it is a gastrointestinal problem and consult a gastroenterologist, only to be diagnosed with an ovarian tumor after a referral. In fact, many cases are already large ovarian tumors at the time of diagnosis, reaching 10 cm or more, even 20 cm in size.

Causes of ovarian tumors

Ovarian tumors are most common in women aged 45 to 64, typically occurring around the time of menopause. The exact cause of ovarian tumors is unclear, but previous research suggests a link to continuous ovulation. Women who have never given birth, never breastfed, have a history of miscarriage or infertility, have a history of breast cancer, started menstruating early, experienced menopause later, had their ovaries overstimulated, or have a family history of ovarian cancer have a relatively higher risk of developing ovarian and peritoneal cancer.

Ovarian tumors can generally be divided into three types:

1. Epidermal ovarian cancer : About 90% of ovarian cancers belong to this type. The lesion or tumor is located in the epithelial layer outside the ovary, and it is usually diagnosed at a very late stage.
2. Germ cell tumors : These originate from cellular mutations in the ovarian germ cells that produce eggs. They are commonly seen in women in their 10s and 20s, and a small number of women in their 30s may also develop them.
3. Stromal cell tumor : This is a mutation in the stromal cells of the ovarian tissue that are responsible for female hormones. Women of any age can develop it, but it is not common, and only about 7% of ovarian tumors are of this type.

Common symptoms of ovarian cancer

The ovaries are located deep within the pelvic cavity, and early-stage ovarian cancer often presents with no obvious symptoms. Therefore, many ovarian tumor patients are diagnosed at a relatively late stage. As the tumor grows, patients may experience persistent abdominal bloating, loss of appetite, feeling full easily, indigestion, frequent urination, difficulty defecating, abdominal discomfort or bloating when lying down, irregular menstruation, fatigue, and weight loss – all common symptoms of ovarian tumors. If the tumor ruptures or other complications occur, pain may occur in the abdomen or pelvis. If ovarian cancer has progressed to the middle or late stages, or even spread to other organs, ascites, nausea, or vomiting may also occur.

Four methods for detecting ovarian tumors

The doctor will first perform a routine clinical examination, manually pressing on the patient's abdomen to assess for any masses or ascites. If suspected, some or all of the following tests will be scheduled to help diagnose whether an ovarian tumor is present:

Ultrasound examination

Pelvic ultrasound can be divided into two types: non-invasive pelvic ultrasound and transvaginal ultrasound, which requires placing an ultrasound probe into the woman's vagina. Pelvic ultrasound can visualize the ovaries, uterus, and bladder, helping to detect the location of ovarian tumors and distinguish between a mass and a fluid-filled cyst. Transvaginal ultrasound can assess whether there is abnormal proliferation, tumors, or irregular shapes in the ovarian tissue.

Blood test

CA125 is an indicator for detecting ovarian cancer. Cancer cells release proteins that enter the bloodstream. By testing a patient's blood CA125 levels, doctors can assess the risk of ovarian cancer, monitor treatment effectiveness, and track recurrence. However, ovarian cancer is not the only cause of elevated CA125 levels; endometriosis, fibroids, and ovarian lesions can also lead to elevated CA125 levels. Therefore, blood test results need to be combined with other tests to aid in diagnosis.

Scan inspection

Computed tomography (CT) scans or magnetic resonance imaging (MRI) scans, using contrast agents, can provide detailed examination of organs and surrounding tissues in the abdominal and pelvic cavities, such as tumor rupture, extent of spread, and abnormal vascular proliferation. This helps doctors determine the size, shape, location, tissue characteristics of the tumor, and the degree to which nearby tissues are affected.

biopsy

It is currently the most accurate method for diagnosing ovarian tumors. Tumor tissue samples can be obtained through laparoscopy or open surgery and then sent to the laboratory to identify the type and stage of the tumor.

Treatment methods for ovarian tumors 

Depending on the type, size, stage of the tumor, and the patient's overall health, doctors may use surgery, chemotherapy, radiotherapy, or targeted therapy to treat ovarian tumors in order to eliminate as many cancer cells as possible.

1. Surgical intervention is the primary treatment for ovarian cancer. Depending on the size and nature of the tumor, and the patient's desire to conceive, doctors may consider partial or complete removal of the ovarian tissue. The area to be removed may include both ovaries, the uterus, fallopian tubes, and surrounding lymph nodes. If the tumor has shown signs of spread, the affected areas must also be removed.
2. Chemotherapy (chemotherapy) : One or two anticancer drugs are injected into the body via intravenous drip to destroy and disrupt the growth and division of cancer cells. However, it usually causes side effects such as nausea, vomiting, hair loss, loss of appetite, and fatigue, making patients feel unwell.
3. Radiotherapy (radiotherapy) : It is not a first-line treatment for ovarian cancer, but it can be used as a supplement to surgery or chemotherapy and is suitable for treating areas where cancer has spread. The principle is to kill or stop the growth of cancer cells with high-energy radiation or particles.
4. Targeted therapy : PARP inhibitors and bevacizumab are commonly used targeted drugs for treating ovarian tumors. They can alter the division, growth, self-repair, and blood supply to cancer cells, leading to tumor cell death. Compared to other treatments, this is a less harmful approach to normal cells, but it still causes side effects that can be uncomfortable for patients.