Once a mesothelioma diagnosis is established, the doctors, may recommend a number of treatments designed to slow the spread of the cancer. These include chemotherapy, radiation, and pneumonectomy, or the removal of all or part of the affected lung. These approaches are often accompanied by pain-relieving or symptom-reducing therapies, called palliative treatment.
The most common approach, however, is chemotherapy, and one of the reportedly most effective drugs emerging from recent research is Alimta (generic name pemetrexed), whose molecular structure was discovered by Edward C. Taylor of Princeton University in New Jersey.
Pemextred, which acts by preventing the formation of RNA and DNA (both essential to cell growth and survival), was later put into clinical trials and commercially developed by Indianapolis, Indiana-based pharmaceutical company Eli Lilly and Company.
It was approved for treatment of malignant pleural mesothelioma by the U.S .Food and Drug Administration, or FDA, in 2004, in combination with Cisplatin (cisplatinum), a platinum-based formulation which acts within living tissue to cause apoptosis, or cell death.
The following list of questions and answers details Alimta’s (and Cisplatin’s) delivery method, regimen, side effects and prognosis:
How is Alimta given?
Before treatment begins, your physician or health professional may give you two 4-milligram tablets of the steroid dexamethasone, or another corticosteroid, to be taken the day before a treatment to reduce the skin rash that Alimta can cause. This can also be given as an injection.
You will also be asked to take folic acid for about five to seven days before Alimta therapy, and continue taking it for the full 21 days, or until therapy is complete. Your physician will also likely administer B-12, in the form of an injection, before you begin treatment, and this B-12 regimen will be followed up about every nine weeks, possibly on the same day of treatment, with – again – a brief interval to observe any negative reactions.
If you are taking non-steroidal anti-inflammatory (NSAID) medicines like ibuprofen, your doctor may ask you to discontinue their use up to five days before treatment (and for several days after the 21-day regimen) to prevent additional stomach upset or bleeding problems. Also tell your doctor about all other prescription and non-prescription drugs you might be taking, including herbal supplements, as these may interfere with Alimta’s effectiveness or cause side effects during treatment.
Alimta is provided to administering physicians and health professionals as a sterile, freeze-dried powder in either 100-milligram or 500-milligram single-dose vials containing pemextred, mannitol, and possibly sodium hydroxide or hydrochloric acid to adjust the pH (acid/base) balance.
Alimta is given intravenously, as a 10-minute infusion, to treat pleural mesothelioma. This administration is followed by a 30-minute interval during which the patient is observed for negative reactions.
How is cisplatin given?
Cisplatin is also given intravenously, after the 30-minute interval, and takes up to two hours to administer. Thus, the entire treatment can require a full three hours.
How often? For how many weeks? What is the time between administrations?
Alimta, followed by Cisplatin, is usually administered for 21 days consecutively, or three weeks, including weekends and holidays, and this continuity of treatment is essential to provide Alimta’s full benefits. Peripherally Inserted Central Catheters.
Will I feel weak afterwards? Sore?
Because this particular combination chemotherapy regimen, Alimta with Cisplatin, can cause low blood cell counts (of both white and red blood cells), you will likely feel weak. You may also experience muscle pain, including pain at the site of the injection, and paleness. You may bruise easily, and feel though your mind isn’t functioning properly, and may be sleepy. Provigil can help.
You will likely experience nausea and vomiting, though these symptoms may not appear for up to 72 hours. If they do, your doctor can give you dexamethasone in combination with metaclopramide, or prochlorperazine. If nausea persists (called “breakthrough nausea”), other anti-emetics can be added as needed.
You may also experience diarrhea or constipation, loss of appetite, skin rashes in spite of the corticosteroids, and mouth sores, all of which can be treated or overcome.
Symptoms requiring attention include tinnitus, loss of high-frequency hearing and deafness. These are more common in children, but signal toxicity, as do anaphylactic-like reactions where there is facial swelling, hives, difficulty breathing, irregular heartbeat and low blood pressure. Cisplatin may also result in renal toxicity.
Where is treatment given?
Because many doctor’s offices and clinics aren’t open on weekends or holidays, patients may be referred, on a one-time basis, to an emergency clinic, or a hospital. In the interests of continued and consistent care, some doctors may direct patients to receive all treatments at a hospital, where staff qualified to administer chemotherapy can provide uninterrupted regimens. If so, patients will be asked to pre-register and given a schedule of when, and where, to appear.
Chemotherapy drugs can be given by a licensed oncologist, an oncological assistant, or a nurse. The primary requirement for those not licensed as physicians, but licensed as nurses or other health care professionals like nurse practitioner, is that they have taken the Oncology Nursing Society’s (ONS) Cancer Chemotherapy Course, and been certified. The ONS and the American Society of Clinical Onocology have developed standards to promote safety in administration.
How do doctors know if the treatment is working? How do they measure success?
Clinical trials of Alimta and Cisplatin as established chemotherapy indicate an increase in patient survival rates of 15 months, almost double the 8-9 month rate typical of other mesothelioma therapies. In fact, about 33 percent of patients experienced shrinking of tumors, and more than 66 percent reported less pain.
Unfortunately, patient reporting of symptoms does not always correlate with survival, according to Dr. Howard West, Director of Medical Therapeutics (Thoracic Oncology), at the Swedish Cancer Institute in Seattle, Washington. Thus, doctors rely on more precise parameters, including medical testing, to determine if treatments are actually working.
These include X-rays, CT (computed tomography) scans, or MRIs (magnetic resonance imaging) to view the tumor, though not all tumors are visible. Blood tests can also be used, to identify the presence (or absence) of mesothelin markers, which are used not only to diagnose mesothelioma but to stage the disease or to determine its progression and severity.
Tests can also determine the presence, and amount, of lactate dehydrogenase (LDH) and C-reactive protein (CRP), which can be used to evaluate treatment methods and response, though neither is a definitive marker in diagnosing mesothelioma itself.
Another test, FDG-PET, uses a F-fluoro-2-deoxy-D-glucose (a combination of a radioneuclide and glucose) injection and is viewed via positron emission tomography (PET) to determine if the tumor has actually shrunk. The FDG works because cancer cells metabolize sugars at a higher rate than normal cells.
Researchers at the University of California Los Angeles are also working on a novel method to determine how, and if, chemotherapies work, in advance of their actual use. The method involves using a probe with radioactive isotopes that allows them to view the chemotherapy drug’s action inside the tumor via positron emission tomography, or PET, scanning – a process that may mitigate more effective treatments.
See also the FAQ on Mesothelioma surgery.
Sources of information on this page: Global Resource for Advancing Cancer Education, Japanese Journal of Clinical Oncology, Elsevier.com