Ovarian Cancer Screening

What is ovarian cancer?

Ovarian cancer is a type of cancer that originates in the ovaries, the female reproductive organs responsible for producing eggs (ova) and hormones such as estrogen and progesterone. The ovaries are almond-sized organs located on either side of the uterus in the pelvis.

What are the types of ovarian cancer?

1. Epithelial ovarian cancer: 

   • This is the most common type, accounting for about 90% of ovarian cancers. It develops in the epithelial cells covering the outer surface of the ovary.

2. Stromal ovarian cancer: 

   • This type forms in the ovarian tissue that produces hormones. Stromal tumors are often diagnosed at an earlier stage than epithelial tumors.

3. Germ cell ovarian cancer: 

   • Germ cell tumors originate in the cells that produce eggs. These tumors are rare and tend to occur in younger women.

4. Borderline ovarian tumors: 

   • These tumors have abnormal cells that may become cancerous but often have a better prognosis than invasive ovarian cancer.

What are the signs and symptoms of ovarian cancer?

Ovarian cancer is often called the "silent killer" because it may not cause noticeable symptoms in its early stages. As the disease progresses, symptoms may include:

• Abdominal bloating or swelling

• Pelvic pain or discomfort

• Feeling full quickly during meals

• Changes in bowel habits, such as constipation

• Frequent urination

• Unexplained weight loss

• Fatigue

• Back pain

How do you test for ovarian cancer?

1. CA-125 blood test: 

   • The CA-125 blood test measures the levels of a protein called CA-125 in the blood. Elevated levels of CA-125 can be associated with ovarian cancer. However, CA-125 is not specific to ovarian cancer and can be elevated for other reasons, such as endometriosis, adenomyosis, fibroids, pelvic inflammatory disease, and gastrointestinal causes.

2. Pelvic ultrasound:

   • Pelvic ultrasound involves detailed images of the ovaries to visualise any ovarian masses with suspicious features of cancer such as solid areas, ascites, bilateral cysts.

FAQs

Who is at risk of ovarian cancer?

1. Women with a positive family history: A family history of ovarian cancer may increase the risk. Ministry of Health stated that women with the following risk factors are at a higher risk:

   • Confirmed BRCA1/2 mutation carriers or untested first-degree relatives of known BRCA1/2 mutation carriers

   • Two or more first degree relatives with ovarian cancer

   • Family history of breast and/or ovarian cancer suspicious of BRCA mutation

2. Age: 

   • The risk of ovarian cancer increases with age, with the highest risk occurring in women over 60.

3. Reproductive history: 

   • Women who have never been pregnant or had their first child after the age of 35 may have a slightly higher risk.

4. Personal history of breast cancer: 

   • Women with a personal history of breast cancer may face an increased risk.

5. Inherited syndromes: 

   • Certain genetic syndromes, such as Lynch syndrome (hereditary nonpolyposis colorectal cancer) and Peutz-Jeghers syndrome, are associated with an increased risk of ovarian cancer.

6. Women on hormone replacement therapy (HRT): 

   • Long-term use of hormone replacement therapy after menopause may slightly increase the risk of ovarian cancer. The risk appears to be higher with the use of estrogen-alone HRT, as opposed to combined estrogen and progesterone therapy.

7. Women with endometriosis: 

   • Endometriosis, a condition where tissue similar to the lining of the uterus grows outside the uterus, is associated with an increased risk of ovarian cancer.

What are the challenges in ovarian cancer screening?

1. Absence of early symptoms: 

   • Ovarian cancer is often referred to as the "silent killer" because it may not cause noticeable symptoms in its early stages. When symptoms do appear, they are often non-specific and may be attributed to other common conditions. This makes it challenging to identify the disease at an early and more treatable stage.

2. Lack of a definitive biomarker:

   • Unlike some other cancers, ovarian cancer lacks a definitive biomarker that can reliably indicate the presence of the disease. While the CA-125 blood test is often used, it is not specific to ovarian cancer and can yield false positives.

3. False positives and overdiagnosis: 

   • Current screening methods, such as the CA-125 blood test and transvaginal ultrasound (TVUS), can produce false-positive results. Elevated CA-125 levels can be associated with conditions other than ovarian cancer, leading to unnecessary anxiety and further testing. False positives can also result in overdiagnosis, leading to unnecessary surgeries.

4. Low prevalence in the general population: 

   • Ovarian cancer is relatively rare compared to other cancers. In the general population, the prevalence of ovarian cancer is low, making widespread screening less cost-effective and potentially leading to an increased number of false positives.

5. Complexity of ovarian tumors: 

   • Ovarian tumors can be complex, with various subtypes that behave differently. Some tumors may be slow-growing, while others are more aggressive. The lack of a one-size-fits-all screening approach adds complexity to the development of effective screening strategies.

6. Limited sensitivity and specificity of screening tests: 

   • The sensitivity and specificity of current screening tests, such as CA-125 and transvaginal ultrasound, are not ideal. These tests may not reliably detect early-stage ovarian cancer, and false negatives can occur, providing a false sense of security.

7. Risk factors are not well-defined: 

   • While certain risk factors, such as a family history of ovarian cancer or mutations in specific genes (BRCA1 and BRCA2), are associated with an increased risk, many cases occur in women without these known risk factors. This lack of clear risk factors hampers the development of targeted screening strategies.

How to confirm the diagnosis of ovarian cancer?

A tissue biopsy is the only thing that can definitively confirm an ovarian cancer diagnosis.

How to manage ovarian cancer?

Managing ovarian cancer involves a multidisciplinary approach that combines surgery, chemotherapy, targeted therapies, and supportive care. The specific treatment plan will depend on the stage of the cancer, the type of ovarian cancer, the patient's overall health, and individual considerations. Here are the key components of managing ovarian cancer:

1. Surgery: Surgery is a crucial component of ovarian cancer treatment. The extent of surgery depends on the stage of the cancer. Common procedures include:

   • Oophorectomy: Removal of one or both ovaries.

   • Salpingectomy: Removal of one or both fallopian tubes.

   • Hysterectomy: Removal of the uterus.

   • Lymph node dissection: Removal of nearby lymph nodes to check for cancer spread.

2. Chemotherapy: 

   • Chemotherapy is often used after surgery to eliminate remaining cancer cells and prevent recurrence. It may be administered intravenously or directly into the abdominal cavity (intraperitoneal chemotherapy). The choice of chemotherapy drugs depends on the specific characteristics of the cancer.

3. Targeted therapies: 

   • Targeted therapies focus on specific molecules involved in cancer growth. For example, drugs like bevacizumab may be used to inhibit the growth of blood vessels that supply tumors. Poly (ADP-ribose) polymerase (PARP) inhibitors, such as olaparib and niraparib, may be used for certain types of ovarian cancer with specific genetic mutations.

4. Hormone therapy: 

   • Hormone therapy may be considered for certain types of ovarian cancer that are hormone-sensitive. This approach aims to block or interfere with hormones that contribute to cancer growth.

5. Immunotherapy: 

   • Immunotherapy drugs, such as immune checkpoint inhibitors, are being investigated in clinical trials for ovarian cancer. These drugs aim to boost the body's immune system to recognize and destroy cancer cells.

6. Follow-up care: 

   • After completing initial treatment, regular follow-up appointments are essential to monitor for any signs of recurrence or complications. Follow-up care may include imaging tests, blood tests (CA-125), and discussions about potential side effects of treatment.

7. Symptom management and supportive care: 

   • Managing symptoms and addressing the side effects of treatment are critical aspects of ovarian cancer care. This may involve medications to alleviate pain, nausea, or other symptoms. Supportive care, including counseling, nutritional support, and palliative care, can enhance the overall well-being of the patient.

8. Palliative care: 

   • Palliative care focuses on improving the quality of life for patients facing serious illnesses. It can be integrated into ovarian cancer management to address symptoms, provide emotional support, and assist with decision-making.