What Is Choriocarcinoma?
Choriocarcinoma is a rare, malignant tumor that develops in the body of the uterus. It is also called chondroblastoma, chorionic carcinoma, and chorioepithelioma. In addition, it is a type of gestational trophoblastic disease (a group of pregnancy-related conditions that develops inside the uterus). Almost all choriocarcinoma develops in the uterus after fertilization (union of the human sperm nucleus with the human egg nucleus). Still, they do occur in the testis or ovary to a small extent.
Choriocarcinoma occurs when cancer develops in the trophoblastic cells (cells that help attach the embryo to the uterus wall and protect the embryo and form a large part of the placenta). It is aggressive and often results in early metastasis (spread to other body parts). They most commonly metastasize to the lungs, vagina, pelvis, liver, brain, kidney, and spleen.
What Are the Different Forms of Choriocarcinoma?
Two different forms of choriocarcinoma include;
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Gestational Choriocarcinoma: Gestational choriocarcinoma occurs due to any gestational activity such as pregnancy, molar pregnancy, abortion, etc. It affects only females since the tumor growth occurs due to gestational activity.
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Non- gestational Choriocarcinoma: Non-gestational choriocarcinoma does not occur due to any gestational activities, and they are a part of germ cell neoplasms. It can affect both males and females. It often has a poorer prognosis than gestational choriocarcinoma.
What Causes Choriocarcinoma?
Choriocarcinoma occurs when cancer develops in the trophoblastic cells. The underlying factors that cause cancer to develop in trophoblastic cells include;
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Ectopic pregnancy (a type of pregnancy in which the fertilized egg grows outside the women's uterus. It is also known as extrauterine pregnancy).
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Abortion.
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Miscarriage.
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Molar pregnancy or hydatidiform mole (a benign tumor that develops in the uterus due to non-viable pregnancy).
What Are the Signs and Symptoms of Choriocarcinoma?
Choriocarcinoma usually develops in older women with high parity (women who have had five or more pregnancies with a gestation period of more than 20 weeks) and in women of low socioeconomic status. Patients may not experience significant symptoms until cancer has reached an advanced stage. The symptoms observed in choriocarcinoma are as follows;
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Vaginal bleeding.
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Abdominal pain.
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Nausea and vomiting.
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Enlargement of the uterus leads to abdominal swelling.
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Cysts or nodule formation in the ovaries.
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Vaginal discharge due to secondary infections.
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Pyrexia (fever of unknown origin).
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Cachexia (a disorder that causes extreme weight and muscle loss).
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High levels of hCG (human chorionic gonadotropin hormone - a hormone produced by the trophoblastic cells).
Choriocarcinoma exhibits varied symptoms when they metastasize to other body parts. If it metastasizes to the lungs and brain, it may show the following symptoms;
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Cough.
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Chest pain.
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Breathing trouble.
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Headache.
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Dizziness.
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Visual disturbances.
Choriocarcinoma metastasis to the lungs exhibits a characteristic cannonball metastatic appearance. Cannonball metastases are nothing but large, well-circumscribed metastases in the lungs.
How Is Choriocarcinoma Diagnosed?
The various diagnostic measures used in choriocarcinoma diagnosis include;
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Pelvic Examination: In a pelvic examination, the doctors look for any abnormal lumps or changes in specific organs in a woman's body, including the uterus, ovaries, bladder, cervix, vulva, and rectum.
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Pap Smear Test: In a pap smear test, the patient is asked to lie on an examination table with legs spread wide. Followed by this, the healthcare provider inserts a device called a speculum into the vagina that keeps the vaginal walls open and facilitates access to the cervix.
The cervix cells are then scraped and sent to the lab for pathological examination. A pap smear test helps identify whether the cells of the cervix are cancerous or not. Patients may feel slight discomfort during the procedure.
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Blood and Urine Tests: The doctor will ask the patient to undertake blood and urine tests to detect the hCG levels. HCG hormone is produced by the trophoblast cells, and its levels are low in non-pregnant women. Therefore, high levels of hCG hormone reported in women who are not pregnant may be a sign of choriocarcinoma.
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Imaging Tests: A pelvic ultrasound helps assess organs and organs within the pelvis by producing images of the structures. For example, in choriocarcinoma, a pelvic ultrasound looks for abnormalities in the uterus, like tumor growth.
Other imaging tests like chest X-ray, CT (computational tomography) scan, and MRI (magnetic resonance imaging) are used in diagnosing metastasis in choriocarcinoma.
What Are the Stages of Choriocarcinoma?
The staging system used for choriocarcinoma is called the FIGO (International Federation of Gynecology and Obstetrics) staging system. It consists of four main stages;
1. Stage1: It is the earliest stage of the disease, and the disease is confined to the uterus.
2. Stage 2: In this stage, the disease has spread outside the uterus but is limited to the genital structures.
3. Stage 3: The disease spreads to the lungs with or without any genital tract Involvement in this stage.
4. Stage 4: In stage 4, the disease has metastasized to other body parts such as the brain or liver.
WHO (World Health Organization) Risk Score as Used by FIGO:
FIGO staging also includes a risk score that WHO develops. This risk score helps in planning effective treatment for each patient. The common risk factors to which risk scores are assigned include;
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Age: The risk score increases with age. For example, patients under 40 years of age are at low risk compared to elderly patients.
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Type of Pregnancy: The risk score is low for molar pregnancy, a slightly higher risk score for abortion or miscarriage, and an increased risk score for a full-term pregnancy.
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Months Since Last Pregnancy: If the timing between the pregnancy and the disease diagnosis is less than four months, then it is a low-risk and high-risk score for more than a year.
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HCG Level in Blood: The greater the level of hCG in the blood, the higher the risk score.
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Amount of Tumor Spread: The risk score is high if the tumor has spread to more areas.
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Part of the Body Affected: If the tumor metastasizes to the lungs or vagina, it has a low-risk score, and metastasis to the spleen or kidney has a slightly higher risk score. Finally, the risk score is highest when the tumor spreads to the brain or liver.
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Size of Tumor: The larger the size of the tumor higher the risk score.
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Previous Chemotherapy: If the patient had chemotherapy for any gestational trophoblastic disease earlier, but it got relapsed, then it is a high-risk score.
The risk score for each risk factor is 0,1, 2, and 4. Once the above risk factors are analyzed, the doctor assigns the risk score. A patient with low risk has a risk score of six or less. A patient with a risk score of seven or more is considered high risk.
How Is Choriocarcinoma Treated?
The treatment options for choriocarcinoma depend on factors like;
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Stage of choriocarcinoma.
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Patients risk score.
Treatment for Low-risk Patients:
The treatment for low-risk patients mainly relies on chemotherapy. Chemotherapy uses anticancer drugs to kill cancer cells. Chemotherapy drugs like Methotrexate or Actinomycin D are used for low-risk choriocarcinoma patients. The dosage of Methotrexate is 5 mg, five times a day, given for five days.
Treatment for High-risk Patients:
The treatment options for high-risk patients or in cases with tumor metastasis include surgery, chemotherapy, and radiation therapy. In high-risk patients, a combination of chemotherapy drugs is used. Combination therapy, including Methotrexate, Actinomycin D, and Cyclophosphamide, is given for high-risk patients.
Surgery is indicated in choriocarcinoma cases with large tumor growth and uterine perforation or rupture. It is also used in high-risk cases where chemotherapy is ineffective. In addition, the doctor may suggest a hysterectomy (a surgical operation that obliterates the uterus) in elderly patients who will not be having children in the future. Hysterectomy is done to destroy the tumor cells.
Radiation therapy treats tumor growths that metastasize to other body parts. It uses high-energy X-rays to kill cancer cells. After treatment, the doctor schedules a weekly follow-up for the patient to check the serum beta-human chorionic gonadotropin hormone levels. A high serum beta hCG level after treatment may indicate the relapse of the disease.
Conclusion:
Choriocarcinoma can be life-threatening if not diagnosed and treated early. An early diagnosis helps treat the disease at an early stage and improves the outcomes. The prognosis varies between gestational and non-gestational choriocarcinoma, with non-gestational choriocarcinoma having a poor prognosis. Treatment options like chemotherapy improve the overall survival of patients. Patients with gestational choriocarcinoma can still have a healthy pregnancy after treatment. But chances of getting pregnant are not possible in patients who have undergone a hysterectomy.
