The R-CHOP Regimen

"Chemotherapy."

The word instills terror, invokes images of hair loss, weakness, sickness. It can be an extraordinarily trying time, for patients and their caregivers. The literally hundreds of different drugs used in chemotherapy treatment can be daunting.

In order to try and remove some of the terror and mystery of chemo, I'm going to use this blog to take an occasional look at the various groups of drugs used in chemo—their names, what they are, and what they do—to cancer cells and to our bodies.

R-Chop is a Regimen

Chemotherapy is typically delivered in regimens, or groups of chemotherapy drugs, which we've come to know by their initials. Regimens are used because different chemo drugs attack cancer cells in different ways and at different stages of the cell cycle—look at it like an all-out assault on cancerous cell growth, or more colloquially, as not putting all your eggs in one basket.

In this entry I'll be looking at one of the more common chemotherapy regimens, R-CHOP

Who is given the R-CHOP Regimen?

R-CHOP has been prescribed as chemotherapy treatment for a number of non-Hodgkin's lymphomas, such as:

• Diffuse large B-cell lymphoma (DLBCL)
• Follicular lymphoma
• Mantle cell lymphoma
• Primary mediastinal B-cell lymphoma
• Extranodal natural killer/T-cell lymphoma, nasal type
• Anaplastic large cell lymphoma

Drugs in the R-CHOP Regimen

The R-CHOP acronym is composed of the following drugs:

• Rituximab
• Cyclophosphamide
• Hydoxydaunorubicin (doxorubicin)
• Oncovin (vincristine)
• Prednisone

Rituximab

Rituximab (Rituxan®) is a new type of drug known as a monoclonal antibody, meaning it's 'trained' to do a very specific job within the body—something like a 'magic bullet'. Rituximab's narrow job is to seek out B-cell lymphocytes by finding a certain protein on the surface of the cell, and kill them. In R-CHOP, rituximab is often given first. Despite being an incredible scientific breakthrough, rituximab has its share of serious potential problems.

Rituximab has been known to cause a drop in blood pressure, a variety of allergic reactions (rashes, swelling, coughing, wheezing etc), or flu-like symptoms like chills in patients. For this reason, the patient is watched closely while receiving this drug for the first time.

Cyclophosphamide

Cyclophosphamide is an alkylating anti-neoplastic agent, which I wrote about earlier; these drugs add chemicals known as an alkyl group to the cell, inhibiting its ability to divide. Cyclophosphamide can irritate your bladder, so drink lots of fluids.

Hydroxydaunorubicin

Hydroxydaunorubicin (doxorubicin) is an anthracycline antibiotic, meaning, in short, that it prevents cancerous DNA and RNA from replicating.

Vincristine

Vincristine (formerly known as Oncovin) is a vinca alkaloid, which I wrote about earlier; a vinca alkaloid works to inhibit cell division during the M phase of the cell cycle.

Vincristine can cause constipation. It can also cause numbness and tingling at the extremities (feet, hands), what's known as peripheral neuropathy.

Prednisone

Prednisone is a steroid that helps with anti-inflammation. Its exact action isn't known, but it does seem to take action on cancerous white blood cells. Unlike the other drugs in this regimen, you will be given prednisone tablets to take home with you.

Prednisone can increase your appetite. It can also irritate your stomach by thinning the layer of protection in your stomach, making it easier for you to feel like you have indigestion. It can also give you mood swings or screw with your blood sugar levels.

How the R-CHOP Regimen is Given

You'll start with a blood test, after which a cannula (a thin tube) will be inserted into a vein either in your arm or on the top of your hand. You'll get your chemotherapy drugs by way of this thin tube.

The prednisone generally comes first; in other words, before you get any drugs through the IV tube, you will have taken a prednisone dose orally (by mouth).

Following that, the rituximab and the other three remaining drugs are given by way of a drip bag hooked up to your IV tube. While R-CHOP will normally only require you to check in as a day patient, the first treatment might take longer and you might have to spend the night at the hospital. The first treatment could take several hours.

Duration of the R-CHOP Regimen

The R-CHOP regimen typically works like this: Your first day of treatment is followed by 5 days taking prednisone tablets at home, followed by another 16 days of rest and recovery. These 21 days complete a single cycle of treatment.

However, sometimes R-CHOP is given in 14 day cycles. The only difference here is that on this cycle, you are given 9 days of rest and recovery, as opposed to 16. Research is underway to try and determine which is a more successful cycle. Be sure to ask your doctor or health care team why they are choosing one R-CHOP cycle over the other.

Side Effects of the R-CHOP Regimen

Below are some common chemotherapy side effects—this is by no means complete. Some patients get hit hard by side effects, others don't. Whatever the case, it's important to keep your doctor informed about how you feel, even if it seems minor to you. Also, keep in mind that your doctor may know of a way to alleviate some of these side effects, but you have to tell him or her about them in order to find out:

• Infections: Bone marrow production of white blood cells might be low, making you susceptible to infections. Call your doctor immediately if your temperature rises over 100. 4 ºF (38 ºC).
• Anemia: Red blood cell count goes down, making you feel exhausted and out of breath.
• Reduced ability to clot: Your blood doesn't have the clotting ability it normally does because of lowered platelets, making bleeding or bruising happen unusually easily.
• Nausea: Vomiting or feeling like you want to vomit. Your doctor can prescribe for you a number of effective anti-emetics to help stem the vomiting.
• Fatigue: Feeling chronically and excessively tired. Extremely common side effect, one that gets worse as chemo treatment goes on.
• Hair loss: Your hair starts falling out, not just on your head but also on other parts of the body. Although many chemo patients find this traumatizing, their hair will likely return on completing treatment, or in some cases, before then.
• Mouth sores: Cotton-mouth, dry-mouth, soreness or ulcers develops in your mouth. Drink lots of water and brush your teeth. To keep your mouth as infection-free as possible during chemo, ask your doctor about any recommendations or prescription mouth washes.

Sources

• The American Cancer Society: Guide to Cancer Drugs
• Everyone's Guide to Cancer Therapy (5th edition). Ed. Ko, Dollinger, Rosenbaum. Andrews McMeel Publishing, 2008