What FOLFOX is
The name combines the initials of its components: FOL, folinic acid (leucovorin), which boosts the next one; F, 5-fluorouracil (5-FU), the "classic" colon chemotherapy; and OX, oxaliplatin. It is used both after surgery (adjuvant treatment, stage III and some stage II) and in metastatic disease, often with bevacizumab or an anti-EGFR.
CAPOX (XELOX) is its tablet-based "sibling": oral capecitabine for 14 days + oxaliplatin every 3 weeks. It is equally effective; the choice depends on preferences, venous access and side-effect profile.
How it is given
Each cycle lasts 14 days. On day 1 you go to the day hospital: oxaliplatin over about 2 hours, leucovorin and a "bolus" of 5-FU, and then you are connected to a portable pump (infusor) with 5-FU that you take home for 46 hours. For this a central line is placed (port-a-cath or PICC). An adjuvant course is 6 cycles (3 months) or 12 cycles (6 months).
Before starting: the DPD test
A small percentage of people lack enough of the enzyme DPD, which clears 5-FU; in them the drug can be very toxic. Since 2020 the European Medicines Agency recommends testing DPD (the DPYD gene) before the first dose. In Spain this is routine practice; if nobody has mentioned it, ask.
Most common side effects
| Effect | What you will notice | What is done |
|---|---|---|
| Cold sensitivity (oxaliplatin) | Tingling or cramps in hands, feet and throat when touching or drinking something cold, in the first 3-5 days of the cycle | Avoid cold: gloves, drinks at room temperature, do not open the freezer without gloves |
| Cumulative neuropathy | Persistent tingling, clumsiness with buttons, loss of feeling in the feet | Report it as soon as it starts: the dose is reduced or oxaliplatin paused so it does not become permanent |
| Nausea | Mainly in the first days | Scheduled anti-sickness drugs; take them even if you feel no nausea at first |
| Tiredness | Cumulative, worse in the first week of the cycle | Gentle physical activity, good sleep, ask for help |
| Diarrhoea / mouth sores (5-FU) | Loose stools, sores in the mouth | Loperamide as prescribed, mouthwashes; report more than 4-6 stools a day or fever |
| Low white cells | Not noticeable unless there is fever | Blood test before each cycle. Fever ≥ 38 °C = emergency department |
| Hair loss | Uncommon with FOLFOX; hair thins but rarely falls out completely | — |
When to call or go to the emergency department
- Fever of 38 °C or more, chills.
- Severe diarrhoea that does not settle with medication, or with blood.
- Vomiting that prevents you from drinking.
- Chest pain, difficulty breathing, severe pain in the arm with the line.
- Mouth sores that prevent you from eating.
What to ask at your appointment
- Have I had the DPD test?
- How many cycles are planned and with what aim (cure, control)?
- What do I do if I notice tingling? Which number do I call out of hours?
- Can I keep working or exercising during treatment?
- FOLFOX or CAPOX? Why one or the other in my case?