Chemotherapy for Ovarian Cancer

Chemotherapy (chemo) is the use of drugs to treat cancer. For ovarian cancer, chemo is used to:

• Kill very small amounts of cancer cells that may still be around after surgery
• Treat cancers that have metastasized (spread)
• Shrink very large tumors to make surgery easier

Most of the time, chemo uses drugs that are injected into a vein (IV) or given by mouth. These are systemic treatments, meaning the drugs enter the bloodstream and reach almost all areas of the body.

In some cases, chemotherapy may also be injected through a catheter (thin tube) directly into the abdominal cavity. This is called intraperitoneal (IP) chemotherapy.

Chemotherapy for epithelial ovarian cancer

Chemo for ovarian cancer usually involves getting two different types of drugs together. Getting a combination of drugs instead of just one drug alone seems to work better as a first treatment for ovarian cancer.

Some of the chemo drugs used in treating ovarian cancer include:

• Carboplatin
• Cisplatin
• Oxaliplatin
• Paclitaxel
• Docetaxel
• Bevacizumab
• Liposomal doxorubicin

Usually, the combination includes a type of chemo drug called a platinum compound (usually cisplatin or carboplatin), and another type of chemo drug called a taxane, such as paclitaxel (Taxol) or docetaxel (Taxotere). These drugs are usually given as an IV (put into a vein) every 3 to 4 weeks.

The typical course of chemo for epithelial ovarian cancer involves 3 to 6 cycles of treatment, depending on the stage and type of ovarian cancer. A cycle is a schedule of regular doses of a drug, followed by a rest period. Different drugs have varying cycles; your doctor will let you know what schedule is planned for your chemo.

Epithelial ovarian cancer often shrinks or even seems to go away with chemo, but the cancer cells may eventually begin to grow again. If the first chemo seemed to work well and the cancer stayed away for at least 6 to 12 months, it can be treated with the same chemotherapy used the first time. In some cases, different drugs may be used.

Intraperitoneal (IP) chemotherapy

For stage III ovarian cancer (cancer that has not spread outside the abdomen) that has been optimally debulked (no tumors larger than 1 cm after surgery), intraperitoneal (IP) chemotherapy might be given in addition to systemic chemo (paclitaxel given in a vein).

In IP chemotherapy, the drugs cisplatin and paclitaxel are injected into the abdominal cavity through a catheter (thin tube). The tube can be placed during the staging/debulking surgery, or later, either by a surgeon using laparoscopy or by an interventional radiologist under x-ray guidance. The catheter is usually connected to a port, a half dollar-sized disk topped with a pliable diaphragm. The port is placed under the skin against a bony structure of the abdominal wall, such as a rib. A needle is placed through the skin and into the port to give chemo and other drugs.

IP chemo gives the most concentrated dose of the drugs directly to the cancer cells in the abdominal cavity. This chemo also gets absorbed into the bloodstream and so can reach cancer cells outside the abdominal cavity.

IP chemotherapy seems to help some women live longer than IV chemo alone, but the side effects are often more severe. It can cause more abdominal pain, nausea, vomiting, and other side effects, which might make some women stop their treatment early. Because of these risks, IP chemo is usually only done if you:

• Have normal kidney function
• Are in good overall heath
• Do not have a lot of adhesions or scar tissue inside your abdomen (belly), which could keep the chemo from reaching all the exposed cancer cells

Chemotherapy for germ cell tumors

If you have a germ cell tumor, you will likely be treated with combination chemo (several different drugs at once). BEP (bleomycin, etoposide, and cisplatin) is the combination used most often.

If the cancer is a dysgerminoma, these are usually very sensitive to chemotherapy and can sometimes be treated with the less toxic combination of carboplatin and etoposide.

Other drug combinations may be used if the cancer isn’t responding to treatment or to treat cancer that has recurred (come back). These include:

• TIP (paclitaxel, ifosfamide, and cisplatin)
• VeIP (vinblastine, ifosfamide, and cisplatin)
• VIP (etoposide, ifosfamide, and cisplatin)
• VAC (vincristine, dactinomycin, and cyclophosphamide)

Chemotherapy for stromal tumors

Ovarian stromal tumors are not often treated with chemotherapy, but when they are, the combination of carboplatin plus paclitaxel or EP (etoposide and cisplatin) is used most often.

Side effects of chemotherapy

Chemo drugs can cause side effects. These depend on the type and dose of drugs given, and the length of treatment. Common side effects include:

• Nausea and vomiting
• Loss of appetite
• Loss of hair
• Hand and foot rashes
• Mouth sores

Chemo can also affect the blood-forming cells of the bone marrow, which can lead to:

• Increased chance of infections (from low white blood cell counts, also called leukopenia)
• Easy bruising or bleeding (from low blood platelet counts. also called thrombocytopenia)
• Fatigue (from low red blood cell counts and other reasons, also called anemia)

These side effects usually go away after treatment is finished. While you are in treatment, tell your cancer care team about any side effects that you are having. There are often ways to lessen these side effects. For example, drugs can be given to help prevent or reduce nausea and vomiting.

Some chemo drugs may have long-term or even permanent side effects:

• Cisplatin can cause kidney damage. To help prevent this, doctors give lots of IV fluid before and after this drug is given.
• Both cisplatin and the taxanes can cause nerve damage (neuropathy). This can lead to problems with numbness, tingling, or even pain in the hands and feet.
• Cisplatin can also damage the nerves to the ear (ototoxicity), which can lead to hearing loss.
• Chemo can also cause early menopause and infertility (being unable to become pregnant), which may be permanent. This is rarely an issue in the treatment of epithelial ovarian cancer, since most women have both ovaries removed as a part of treatment.
• Rarely, some chemo drugs can permanently damage bone marrow. This can later cause a second cancer of the bone marrow, such as myelodysplastic syndrome or even acute myeloid leukemia. Your cancer care team knows which drugs can cause this problem and will discuss this possibility with you. Usually, the benefits of treating ovarian cancer offset the small chance that any of these drugs will cause another cancer.
• Ifosfamide can cause irritation and bleeding of the bladder lining (hemorrhagic cystitis). This can usually be prevented by giving the drug mesna with the ifosfamide.

Other drugs can have other side effects, so ask your doctor what side effects to expect from the treatments you will receive.

Most side effects improve once treatment is stopped, but some can last a long time and may never go away completely.

What’s new in chemotherapy for ovarian cancer?

New chemotherapy (chemo) drugs and drug combinations are being tested.

When the drugs cisplatin and carboplatin stop working, the cancer is said to be platinum resistant. Studies are looking for many ways to make these cancers sensitive to these drugs again. Different strategies include:

• Looking closely at what specific mechanisms and proteins are involved in making ovarian cancer cells resistant.
• Developing drugs that can keep the cancer cells from becoming resistant to the chemo by blocking channels that pump chemotherapy out of the cancer cell.
• Trying to understand why certain cancer cells are not damaged by chemotherapy which allows it to keep growing.