Ovarian cancer

Ovarian cancer is a malignant tumor that develops in one or both ovaries, part of the female reproductive system. The ovary is a reproductive female gland in charge of producing eggs and releasing sexual hormones.

The ovaries are small, almond-shaped glands located on each side of the uterus in the female pelvic region.

When a woman is in her childbearing years, the ovaries alternate to produce a single egg each menstrual cycle. The ovaries also produce and release estrogen and progesterone (female sexual hormones) that regulate the menstrual cycle and pregnancy.

The most common types of ovarian cancer are:

• Epithelial ovarian tumors: they represent 90% of ovarian tumors. This type of cancer derives from the cells lining the surface of the ovaries. They are most common in women over the age of 60. Based on the features of this type of tumor, it can be subdivided into:
  • Serous carcinomas
  • Clear cell carcinoma
  • Mucinous carcinoma
  • Endometrioid carcinoma
  • Brenner tumors
• Ovarian germ cell tumors: they represent 5% of ovarian tumors. They develop in the egg-producing cells of the ovary. Frequent in adolescents and young women. The most common ovarian germ cell tumors are teratomas, dysgerminomas, endodermal sinus tumors, and choriocarcinomas.
• Ovarian stromal tumors: they derive from the cells of the structural tissue (stroma) that holds the ovaries in place and produce sexual hormones.

Ovarian cancer commonly affects women over the age of 50. In fact, more than half of cases appear in women over 65 years old. The risk of developing the disease increases with age.

In developed countries, ovarian cancer accounts for 4% of all cancers in women.

The precise cause remains unknown. However, there are several risk factors that increase the chances of developing the disease:

• Women who have not been pregnant or had children
• Family history of breast, ovarian, uterine, prostate or colorectal cancer
• Previous history of breast cancer
• Use of estrogens in postmenopausal women for 10 years or more

Ovarian cancer does not often show symptoms in the first stages, making it difficult to diagnose it early. Only 20% of cases are diagnosed during the first stages.

Some symptoms, although frequent in other diseases, may correspond to ovarian cancer. Common symptoms may be:

• Digestive disorders: abdominal distension, flatulence, constipation, indigestion, early satiety, etc.
• Abdominal or lumbar discomfort
• A need to urinate frequently
• Nausea or vomiting
• Abdominal pain or swelling
• Loss of appetite
• Fatigue
• Painful sexual intercourse
• Vaginal bleeding in postmenopausal women

If ovarian cancer is suspected, the next diagnostic tests can be carried out:

• Bimanual pelvic exam in search of any abnormalities of the reproductive organs
• Imaging studies of the pelvic region such as ultrasounds, Magnetic Resonance Imaging (MRI) or Computed Tomography (CT)
• Blood tests measuring the levels of tumor markers such as CA-125. Increased levels of this tumor marker may be found in 80% of women suffering from ovarian cancer
• Barium enema x-ray to check if the cancer has spread to other organs
• Laparoscopy to visualize the organs inside of the abdominal cavity

Ovarian cancer may have the following stages:

• Stage I: the cancer is confined to one or both ovaries
• Stage II: the cancer is present in one or both ovaries and has spread to the uterus, fallopian tubes or other organs within the pelvic cavity
• Stage III: the cancer is present in one or both ovaries and has spread to the lymph nodes or other organs within the abdominal cavity such as the surfaces of the liver or intestines
• Stage IV: the cancer is present in one or both ovaries and has spread to other organs like the liver or lungs

The treatment mainly depends on the stage of the cancer and the woman's age.

The most common procedures performed to the tumor resection are:

• Surgery: complete removal of the ovary (oophorectomy) may be necessary
• Chemotherapy
• Radiotherapy

It is estimated that only 50% of women diagnosed with ovarian cancer live more than 5 years after the diagnosis. This is mainly due to the cancer often being detected during later stages of the disease.

Nonetheless, with early detection, the survival rate after 5 years of the diagnosis can rise above 95%.