What Is FOLFOX Chemotherapy?

FOLFOX is not one drug. NCI lists three components by name.

• FOL is leucovorin calcium, also called folinic acid.
• F is fluorouracil, often written 5-FU.
• OX is oxaliplatin.

NCI's reason for combining them is short. Combinations usually work better than single drugs. Different drugs kill cancer cells in different ways.

Knowing the three names matters. Side effects and dose changes attach to one drug, not to the acronym. A nurse may say the team is dropping the oxaliplatin. The other two usually continue.

NCI lists colorectal cancer as the main use for FOLFOX. Its oxaliplatin page is more exact. Oxaliplatin is approved for advanced colorectal cancer. It is also approved for stage III colon cancer after surgery to remove the cancer. In both, it is used with fluorouracil and leucovorin calcium.

The phrase after surgery marks the adjuvant setting. NCI's patient summary describes stage III treatment as resection and anastomosis. That means taking out the diseased segment and rejoining the bowel. Chemotherapy may follow.

For stage IV and recurrent disease, NCI describes chemotherapy with or without targeted therapy. Six chemotherapy drugs are named. They are capecitabine, fluorouracil, irinotecan, leucovorin, oxaliplatin, and trifluridine with tipiracil. Seven targeted drugs are named. They are bevacizumab, cetuximab, fruquintinib, panitumumab, ramucirumab, regorafenib, and ziv-aflibercept.

So FOLFOX is often a backbone. Other drugs get added to it. It is rarely the whole plan.

MedlinePlus says oxaliplatin is a liquid injected into a vein. It is usually given once every fourteen days. That two-week rhythm shapes the whole regimen.

Fluorouracil also goes into a vein. A doctor or nurse gives it in a hospital or medical facility. MedlinePlus warns that a doctor skilled in chemotherapy must oversee it. The reason is the serious effects it can cause.

Ask your team to write down three things before cycle one. Get the date of each planned infusion. Get the total number of cycles. And ask which drug is given first on infusion day.

This is the instruction that surprises people most, and it is specific to oxaliplatin.

MedlinePlus warns that cold air or cold objects can make oxaliplatin effects worse. The rule runs five days after a dose. Avoid cold drinks and cold food. Avoid cold objects, air conditioning, freezers, and cold water. In cold weather, cover your hands, feet, and face before going out.

Plan for it. Take drinks at room temperature. Use a straw. Warm the car before driving. Keep gloves near the refrigerator, and skip the ice machine. These sound small until the first mouthful of ice water tightens your throat.

MedlinePlus lists common nerve effects of oxaliplatin. They include numbness, burning, or tingling in the fingers, toes, hands, feet, mouth, or throat. Raised sensitivity is common too, above all to cold.

Report these early, not at the end. Teams usually manage nerve damage by lowering the oxaliplatin dose. Sometimes they stop that one drug and keep the other two. A change made while symptoms are mild is easier to reverse. Waiting until buttons, stairs, or handwriting suffer makes it harder.

Tell the team what you cannot do, not just what you feel. "I cannot feel the car keys in my pocket" is more useful than "some tingling."

MedlinePlus notes that your doctor may run a genetic test before starting fluorouracil. The point is to see how well you will tolerate it. Some people break the drug down slowly. A standard dose can then cause severe harm.

Ask two questions if this applies to you. Which gene is being tested? And will the result be back before cycle one? A result that lands after treatment starts cannot protect the first dose.

MedlinePlus is blunt about oxaliplatin. It may cause severe allergic reactions. These may start within a few minutes of the dose. They may cause death.

Report these at once during or right after an infusion. Watch for rash, hives, trouble breathing, throat swelling, or dizziness. Do not wait for the nurse's next round. Say something while it is happening.

• Fever of 100.4 degrees F, or 38 degrees C, or higher. NCI treats fever during cancer treatment as urgent. Call before taking a fever reducer, since it can hide the problem.
• Diarrhea. NCI grades up to six bowel movements above your normal daily number as usually manageable at home. Seven or more above normal is grade 3 or 4, which NCI describes as potentially life-threatening. Count them.
• Mouth or throat sores. MedlinePlus lists these among fluorouracil effects needing prompt attention. So are vomiting, chills, and signs of infection.
• Unusual bleeding or bruising, or blood in urine or stool.
• Loss of balance, trouble speaking, or chest pain. Also trouble breathing, vision changes, or swelling of an arm or leg. MedlinePlus lists all of these as reasons to call a doctor at once after oxaliplatin.
• Pain, burning, redness, or swelling at the infusion site.

• How many cycles are planned, and is this adjuvant or for metastatic disease?
• Which drug gets reduced or dropped first if I have side effects?
• Was a genetic test ordered before fluorouracil, and when does it result?
• What is my anti-nausea plan, and do I take anything before I feel sick?
• Which phone number is answered overnight and on weekends?
• What exactly should I do in the first 24 hours if diarrhea starts?

For related reading, see Targeted Therapy vs Chemotherapy, Biomarker Testing and Precision Medicine, and Cancer Staging.

• National Cancer Institute — FOLFOX
• National Cancer Institute — Oxaliplatin
• National Cancer Institute — Colon Cancer Treatment (PDQ), Patient Version
• MedlinePlus — Oxaliplatin Injection
• MedlinePlus — Fluorouracil Injection
• National Cancer Institute — Diarrhea and Cancer Treatment
• National Cancer Institute — Infection and Neutropenia during Cancer Treatment