What is ovarian cancer?
Ovarian cancer is the second most common gynecological neoplasm in women, second only to cervical cancer.
The absolute majority of ovarian cancers – 95% – are derived from epithelial cells, that is, the cells that line the ovary. The other 5% come from germ cells (those that form eggs) and stromal cells (those that produce most of the female hormones).
It is the seventh most common type of cancer in women worldwide, with about 314,000 new patients diagnosed with the disease each year.
In Brazil, it also ranks seventh among the most incident neoplasms in women (excluding non-melanoma skin tumors). For 2020, INCA (National Cancer Institute) estimated 6,650 new cases in the country.
Ovarian cancer subtypes
It is estimated that there are more than 30 types of ovarian cancer. They are named according to the type of cells where they originate. The three main groups are:
- Epithelial ovarian carcinoma – comes from the surface of the ovary (the epithelium) and is the most common subtype. Uterine tube cancer and primary cancer of the peritoneum are included in this group;
- Germ cell carcinoma of the ovary – originates in the reproductive or germ cells of the ovaries, that is, those that give rise to the eggs;
- Stromal cell carcinoma of the ovary – forms in the cells of the connective tissue.
There is also hypercalcemic small cell carcinoma of the ovary, which does not fit into the three groups above and is extremely rare. It has not yet been identified in which type of cells it originates.
Symptoms and signs of ovarian cancer
Ovarian cancer is a silent disease and in its early stages usually has no specific symptoms. As the tumor grows, it can cause:
- Swelling in the abdomen;
- Pain in the abdomen
- Pain in the pelvic region, back, or legs;
- Abnormal bowel function (constipation or diarrhea)
- Constant fatigue
- Loss of appetite and weight for no apparent reason
- Abnormal vaginal bleeding, especially after menopause
- Increased frequency and/or urgency to urinate.
Ovarian cancer diagnosis
There is no specific test for ovarian cancer screening (like a Pap smear for cervical cancer or mammography for breast cancer). For this reason, and associated with the fact that the symptoms of ovarian cancer are easily confused with other less serious diseases and health conditions, its diagnosis is made at an advanced stage of the disease.
The combined symptoms that raise the alert signal of specialists are swelling and pain in the abdomen, loss of appetite and weight, fatigue, and changes in the functioning of the bowel and urinary tract.
In the face of this picture, a clinical gynecological examination and laboratory tests, and abdominal imaging (which help identify the presence of ascites – or accumulation of fluid – and the extent of the disease in women with suspected intra-abdominal dissemination) will be performed. If ovarian cancer is suspected, a surgical evaluation is performed.
A chest examination (X-ray or CT scan that helps to detect pleural effusion, presence of lung metastases, or other changes) should also be performed.
Ovarian cancer can be treated with surgery or platinum-based chemotherapy. The choice depends on the type of tumor, the staging (stage the disease is in), the age and clinical conditions of the patient, and whether the tumor is initial or recurrent.
For early stages, the approach is surgery with or without chemotherapy. Advanced stages can be treated with surgery followed by chemotherapy, chemotherapy followed by surgery, or chemotherapy alone.
To prevent or increase the chance of diagnosing ovarian cancer at an early stage, women should be aware of symptoms, especially if several occur at the same time, and risk factors, especially after the age of 50.
The risk factors for ovarian cancer are:
- Age – the older the age, the higher the incidence of epithelial ovarian carcinoma;
- Reproductive factors – women who have never had children tend to have an increased risk for ovarian cancer (on the other hand, those who take oral contraceptives – birth control pills – see this risk decrease);
- Hormonal factors – early menarche (first menstruation before the age of 12) and late menopause (after the age of 52) may be associated with a higher risk of ovarian cancer;
- Family history – of ovarian, colorectal, and breast cancers, especially in first-degree relatives;
- Genetic factors – mutations in genes such as BRCA1 and BRCA2;
- Excess body weight.
In case of suspicion, the woman must be evaluated by a gynecologist, who will proceed with the necessary exams for her case.