Gastric cancer originates in the lining of the stomach and is a significant global health concern. For advanced or recurrent cases, combination chemotherapy is a primary treatment method. One of the most widely used regimens is FOLFOX, a multi-drug combination that attacks cancer cells. This article provides an overview of the FOLFOX regimen, its components, the treatment process, management of side effects, and how its effectiveness is evaluated.
Understanding the FOLFOX Regimen
The name FOLFOX is an acronym for the three drugs in the regimen: Folinic acid, Fluorouracil (5-FU), and Oxaliplatin. Each component has a distinct role, and they work together to be more effective than a single agent.
Folinic acid, also known as leucovorin, is a form of the B vitamin folic acid. It is not a chemotherapy drug but a helper molecule that enhances the effectiveness of Fluorouracil. Administering folinic acid increases the concentration and duration of 5-FU’s active form within cancer cells.
Fluorouracil, or 5-FU, belongs to a class of drugs called antimetabolites. These drugs interfere with the metabolic processes of cells, particularly the creation of DNA and RNA. 5-FU mimics a natural compound, tricking cancer cells into incorporating it into their DNA, which halts their growth and replication.
The final component, Oxaliplatin, is a platinum-based chemotherapy drug. Oxaliplatin directly targets the DNA of cancer cells by forming chemical bonds, or adducts, with the DNA strands. These adducts create physical obstructions that prevent DNA from replicating, triggering programmed cell death (apoptosis) in the cancer cells.
The Treatment Process
FOLFOX chemotherapy follows a structured schedule, administered in two-week cycles. This 14-day cycle includes drug delivery followed by a rest period, allowing the body to recover. A complete course may consist of up to 12 cycles over six months, but the duration can be adjusted based on the patient’s response and tolerance.
The drugs are delivered intravenously (IV). To avoid repeated needle sticks, many patients have a central venous access device, like a port-a-cath or PICC line, surgically placed. This device provides a stable entry point into a large vein, making infusions more comfortable.
A treatment day begins at an infusion center where oxaliplatin and folinic acid are given as a two-hour IV drip. This is followed by a quick injection (bolus) of 5-FU. The rest of the 5-FU dose is given as a continuous infusion over the next 46 hours.
This extended infusion is managed outside the clinic using a small, portable pump, allowing patients to return home. After 46 hours, the patient returns to the clinic or a home care nurse visits to disconnect the pump.
Managing Side Effects
The drugs in the FOLFOX regimen can affect healthy, rapidly dividing cells, leading to side effects. A common side effect of oxaliplatin is peripheral neuropathy, which is nerve damage in the hands and feet. This manifests as numbness, tingling, or pain, often triggered or worsened by cold exposure. Patients should wear gloves when touching cold items, avoid iced drinks, and cover their skin in cool weather.
Fluorouracil (5-FU) is associated with gastrointestinal issues. Diarrhea should be managed promptly with medication to prevent dehydration. Mouth sores (mucositis) can also occur, and special mouthwashes can help. Another side effect is hand-foot syndrome, characterized by redness, swelling, and peeling on the palms and soles, which can be managed with moisturizers.
General side effects also occur with FOLFOX. Fatigue is a pervasive symptom, and nausea and vomiting are possible but often well-controlled with anti-sickness medications. The treatment can suppress bone marrow’s ability to produce blood cells, leading to a drop in white blood cells (increasing infection risk), red blood cells (causing anemia), and platelets (leading to easy bruising or bleeding).
Evaluating Treatment Efficacy
Regular monitoring is used to determine if FOLFOX is working. Physicians use several tools, including imaging tests like computed tomography (CT) scans, which are performed periodically to assess tumor size. These scans show if tumors have shrunk, remained stable, or grown.
Blood tests are also used to monitor efficacy. Some gastric cancers release proteins called tumor markers, and tracking these levels can indicate if the cancer is diminishing. Routine blood work also checks blood cell counts to ensure the patient is tolerating the chemotherapy.
The goal of FOLFOX varies by cancer stage. In a neoadjuvant setting, it is given before surgery to shrink tumors. As an adjuvant therapy, it is administered after surgery to eliminate remaining cancer cells and reduce recurrence risk. For advanced or metastatic cancer, the goal is palliative, aiming to control growth, manage symptoms, and improve quality of life.