Chemotherapy is one of the most commonly used treatments for cancer. The standard first-line chemotherapy treatment for mesothelioma is pemetrexed (Alimta®) and Cisplatin. Some recent studies show that combining these drugs with bevacizumab (Avastin) can improve the effectiveness of chemotherapy against mesothelioma.
Chemotherapy (literally “chemical therapy”) is the use of certain medications to kill cancer cells and prevent them from multiplying. A number of different chemotherapy drugs are available to treat mesothelioma, although some of these drugs have proven to be more successful than others.
How Chemotherapy Treats Mesothelioma
Chemotherapy can be used to treat mesothelioma patients in two ways. Either or both of these methods may be used in conjunction with surgery and/or radiation, depending on the treatment plan developed by the doctor and the patient.
Chemotherapy can be given intravenously or as a pill. It then travels throughout the bloodstream and reaches the entire body. Systemic chemotherapy carries the most side effects because in addition to killing cancer cells, it also kills other fast-growing cells such as hair and blood cells.
In some cases, chemotherapy can be delivered directly to the area where tumors have formed, often with fewer side effects than systemic chemotherapy. Intrapleural chemotherapy and heated intraperitoneal chemotherapy (HIPEC) have become more popular in recent years, with great results.
First-Line and Second-Line Chemotherapy
Chemotherapy treatments are often discussed as being first-line and second-line (or even third-line) treatments. These refer to the chemotherapy treatments given first, second, third, and so on, based on their effectiveness.
The most common first-line treatment for mesothelioma is a combination – often called a “cocktail” – of pemetrexed and a platinum-based drug such as cisplatin or carboplatin. This combination has been found to be the most effective in treating mesothelioma, and therefore, it is usually administered first.
If the first-line treatment does not work, a second-line treatment may be tried. There is currently no consensus within the medical community about the best second-line treatment for mesothelioma. Doctors will often make their best decision on which drugs can best treat the disease based on the patient’s specific circumstances.
Mesothelioma Chemotherapy Drugs
A number of different chemotherapy drugs can be used to treat mesothelioma. The recommended chemotherapy drug will vary with each patient. Oncologists choose the drugs they believe will most benefit the patient while also taking into consideration side effects and other important issues.
Currently, the most widely used drug and the one with which doctors have had the most success is Pemetrexed (Alimta®). This drug is usually used in tandem with a platinum agent like Cisplatin and has been shown to add several months to the patient's mesothelioma life expectancy in many cases.
Pemetrexed is the most common chemotherapy drug used to treat mesothelioma, often given in conjunction with cisplatin. It is an injected drug, and patients will often be given corticosteroids and prescribed vitamin B9 (folic acid) and B12 supplements to prevent certain harmful side effects.
Cisplatin is a platinum-based chemotherapy drug administered through an IV. Along with pemetrexed, it is one of the most common mesothelioma drugs. In many cases, doctors will treat mesothelioma patients with cisplatin for unresectable tumors (i.e., when surgery is not an option).
Another platinum-based drug, carboplatin was derived from cisplatin in the 1980s. Although it typically has fewer and milder side effects than cisplatin, it can also inhibit the body’s production of blood cells, leading to an increased likelihood of fatigue and infection.
Typically administered in combination with carboplatin, gemcitabine is used to treat lung, bladder, and ovarian cancers. In clinical trials, it has been shown to be a relatively effective chemotherapy treatment for mesothelioma, and is often used as a second-line treatment.
Granted orphan drug status by the FDA in 2007, ranpirnase is an enzyme that has been shown in clinical trials to effectively kill mesothelioma cells by breaking down their RNA. It is unique in that it does this without affecting healthy cells, which severely reduces the potential side effects of chemotherapy.
Primarily used to treat non-small-cell lung cancer (NSCLC), vinorelbine has also been shown to be somewhat effective against mesothelioma. It works by triggering apoptosis (programmed cell death) in cancer cells.
Other chemo drugs used to treat mesothelioma patients include vinorelbine, mitomycin and raltitrexed. These are generally used in combinations but may be used alone if the patient is unable to tolerate two drugs.
The recommended chemotherapy drug will vary with each patient. Oncologists choose the drugs they believe will most benefit the patient while also taking into consideration side effects and other important issues surrounding the use of chemotherapy. It may take more than one try to discover which drugs will be best suited to the patient.
Hyperthermic Intraperitoneal Chemotherapy (HIPEC)
Another option which has been proven highly effective in treating peritoneal mesothelioma that has not metastasized outside of the abdomen is Hyperthermic Intraperitoneal Chemotherapy (HIPEC). This procedure combines surgery with a concentrated dose of chemotherapy in the abdomen with minimal exposure to the rest of the body.
Following a peritonectomy and/or cytroreductive surgery to remove parts of the peritoneum and any visible tumors in the abdomen, a heated chemotherapy solution is introduced into the abdominal cavity. After the roughly 100-103 degree solution is pumped into the abdomen, it circulates for one and half to two hours reaching all exposed areas aiming to kill any cancer cells that may not have been removed during surgery. This procedure is beneficial as it allows for a more concentrated dose of chemotherapy while not subjecting the rest of the body to the potential toxic effects of the drug.
Side Effects of Chemotherapy
Chemotherapy can cause many side effects in mesothelioma patients. Most of these adverse effects are short term and will go away soon after treatment ends. Others, however, can last long time, in some cases even years after the chemotherapy has ended.
Patients or their loved ones should report all chemotherapy side effects to the patient’s medical team, even if they are deemed “common” or seem mild. This is especially important after the first treatment, when it may be difficult to predict how the patient will react to certain drugs.
Characterized by memory loss and an inability to focus or multitask, this condition is reported by a large number of mesothelioma patients who receive chemotherapy. While there is no “cure” for chemo brain, it can often be managed through exercise, a healthy diet, and routines that help patients organize their daily life.
Many types of chemotherapy kills all types of fast-growing cells, which includes hair. As a result, a mesothelioma patient’s hair may fall out all over the body, not just on the head. Note, however, that not all types of chemotherapy cause hair loss, and each individual’s reaction may be different.
Also called mucositis, chemotherapy can cause an inflammatory reaction of the mucous lining in the upper gastrointestinal tract, causing sores in the mouth, lips, throat, and surrounding tissue. As one of the most painful side effects of chemo, these sores can interfere with nutrition by making it difficult to chew or swallow and affecting taste. While these mouth sores cannot be prevented, they can be managed through pain medications.
Patients are often given an antiemetic drug before chemotherapy sessions to lessen the chance of stomach distress. Inform your doctor if nausea gets out of hand and lasts more than a day or two, or if it interferes with your ability to eat. Many newer chemotherapy drugs are less likely to cause nausea and vomiting than older drugs.
Low Blood Cell Counts
Fast-growing blood cells, including both red and white blood cells, can be killed by chemotherapy, which can compromise the body’s immune response and reduce the flow of oxygen to parts of the body. This can lead to an increased potential for infection, easy bruising and bleeding, and fatigue.
Chemotherapy is generally given intravenously or it may also be administered in pill form. This type of chemo is called “systemic” chemotherapy—it travels through the blood stream and reaches the entire body. Systemic chemotherapy carries the most side effects because it not only does the job it is meant to do—kill fast-growing cancer cells—but, unfortunately, it also kills other kinds of fast-growing cells such as hair and blood cells. Hence, many people undergoing chemotherapy treatment will lose their hair and suffer low white or red blood cell counts.
Some pleural mesothelioma patients may be candidates for a different kind of chemotherapy that more closely targets the tumor and causes fewer side effects. Known as intrapleural chemotherapy, this method involves infusing drugs via a catheter into the chest area—the site of the primary tumor. This intracavitary chemotherapy treatment has proven to be most successful in treating cancers that are still limited to just the pleural surface. A similar procedure is available for those who suffer from peritoneal mesothelioma.Sources
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