Ovarian cancer is a cancer that originates in parts of the female reproductive system called ovaries. These cancers often do not produce any symptoms during the early stages and are often detected in advanced stages, when the cancer has spread to the other parts of the abdominal cavity. Also, the symptoms in the advanced stage are rather non-specific and include early satiety, bloating sensation, abdominal distension, problems in bowel and bladder habits, which are easily confused with other disease conditions, resulting in delay in patients seeking timely medical consultation.
The female reproductive system consists of two ovaries on each side of the uterus. These ovaries are responsible for the production of eggs and hormones such as estrogen and progesterone. Cancers developing in ovaries are called ovarian cancer. Approximately 70% cases of ovarian cancer are detected in advanced stage due to absence of any particular symptoms in early stages.
The causes of ovarian cancer are not very clear, however, factors have been identified that may increase the risk of the disease. These factors include:
- Old age: Ovarian cancer is more commonly seen in women above 50 years of age. Although, women at old age groups are at a risk.
- Infertility: Infertility may increase risk of ovarian cancer in nulliparous women.
- Genetic Mutations: A few cases of ovarian cancers have been found to be linked with inherited genetic changes. These genes called as the breast cancer gene 1 and breast cancer gene 2, or BRCA 1 and BRCA 2, increase the risks of ovarian cancer apart from breast cancer. Other genetic changes that are associated with the Lynch syndrome also increase the risk of ovarian cancer.
- Family History: If an immediate family member has been diagnosed with ovarian cancer or breast cancer, the risk of a woman getting ovarian cancer increases.
There are various types of ovarian cancers. Some of these are mentioned here:
- Epithelial tumours begin in the epithelial cells of the ovary, that is, the thin layer surrounding the outer covering of the ovary. These include:
- Serous papillary carcinoma
- Mucinous carcinoma
- Clear cell carcinoma
- Brenner’s or Transitional carcinoma
- Carcinosarcoma or Mixed Mullerian tumors
- Stromal tumours begin in the sex cord from the sex cord (eg, Sertoli cell tumor, granulosa cell tumor) or stromal cells (eg, Fibroma, Thecoma, Leydig cell tumor) or both (eg, Sertoli-Leydig cell tumor) or stromal cells of the ovary.
- Germ cell tumours (GCT) are the tumours in the germ cells i.e. egg-producing cells of the ovaries. These include:
- Teratoma (Immature or Mature)
- Yolk sac/Endodermal sinus tumor
- Mixed GCT
Ovarian cancer in the early stages may not present with any symptoms. However, some cases get detected incidentally due to ultrasound or CT scan done for investigating other problems. Occasionally, early stage ovarian cancer can present with acute onset abdominal/pelvic pain due to torsion of the ovarian pedicle. Symptoms at later stages may include:
- Abdominal bloating or swelling
- Early satiety
- Weight loss
- Abnormal vaginal bleeding
- Discomfort or fullness in lower abdomen
- Changes in bowel or bladder habits, such as constipation or straining while passing urine
The symptoms can appear in different forms as mentioned above and hence, if you are experiencing any of these symptoms, especially for more than 2-3 weeks, you should consult a doctor.
Once, you see a specialist, the following tests may be carried out:
- A physical exam: A through physical examination will be carried out, after taking a detailed history of your symptoms
- Ultrasound: An abdominal +/- transvaginal ultrasound is usually the first test done to see if any suspicious ovarian masses are present.
- Blood tests: Routine blood tests along with special tests called tumor marker levels will be asked for eg CA 125, CEA, CA 19.9 etc.
- CT scan: A CT scan of the chest, abdomen and pelvis is done to determine the stage of disease; which in turn will help decide the best treatment sequence for a given patient.
- MRI scan: An MRI scan may sometimes be asked for, especially in early cases of ovarian masses to confirm or rule out suspicious findings on CECT scan.
- PET CECT scan: A PET CT scan may be suggested in advanced or recurrent cases to rule out spread of cancer to other sites, eg lungs, liver, bone, etc.
- Diagnostic laparoscopy and biopsy: In advanced cases, a diagnostic laparoscopy may be advised to document the spread of the disease. A biopsy can be performed at the same time to determine the exact histopathological type of ovarian cancer, which may help in deciding the best treatment in a given patient.
The treatment for ovarian cancer depends upon the stage and type of cancer.
Surgery: Surgical procedures to remove ovarian cancer include:
- Staging: Staging surgery includes removal of uterus with both ovaries, pelvic as well abdominal lymph nodes and total omentectomy. It is carried out in women who have completed their families and in case of early ovarian cancer. In women who wish to maintain their fertility, the affected ovary only along with lymph nodes and omentum are removed, preserving the opposite normal ovary and uterus. This is termed as ‘Fertility preserving surgery’.
- Cytoreductive surgery: This is carried out in cases of advanced ovarian cancers and can be carried out before or after chemotherapy. In addition to staging surgery, peritoneum i.e. lining of the abdominal cavity, which has deposits of cancer in advanced cases along with organs like rectum, colon, small bowel, appendix, gall bladder are also removed depending on the spread of cancer.
Chemotherapy: Chemotherapy in the form of injections may be suggested depending on the stage of disease.
- Adjuvant chemotherapy: Is the chemotherapy given after surgery, usually, 6 cycles every 2-3 weeks.
- Neoadjuvant chemotherapy: When chemotherapy is given before surgery it is called neoadjuvant chemotherapy, wherein 3 cycles are given every 3 weeks, before surgery, the remaining 3 cycles then given as adjuvant chemotherapy, after surgery.
- Intra-peritoneal chemotherapy: This is a special form of delivering chemotherapy directly into the peritoneal (abdominal cavity) in patients with advanced ovarian cancer. An intra-peritoneal (IP) port system is introduced underneath the skin of the abdominal wall with a tubing passed into the abdominal cavity, under general anaesthesia. This new treatment delivery system has been used successfully as neoadjuvant as well as adjuvant treatment also, especially in patients with peritoneally metastasised ovarian cancer.
Targeted therapy:Targeted therapy uses drugs to target specific proteins within the cancer cells, to kill them. For example, Bevacizumab targeting VEGF protein in ovarian cancer cells may be suggested during treatment for ovarian cancer.
Immunotherapy:In advanced cases, biological therapy or immunotherapy may be suggested for treatment. Immunotherapy targets the cells, which affect the body’s immune response and helps the body in killing cancer cells.
There is no particular way to prevent ovarian cancer. However, pre-screening for females who are at a high risk of cancer can be done to prevent presenting at advanced stages of cancer.