Cisplatin is a chemotherapy medication used to treat various cancers. It belongs to the class of platinum-coordinating compounds, which are cell cycle-nonspecific alkylating agents. The drug is effective against several types of solid tumors and has contributed to improved survival rates for certain cancers since its introduction.
How Cisplatin Works Against Cancer
After entering the bloodstream, cisplatin is distributed throughout the body and can passively diffuse across the cell membrane into the cytoplasm of both healthy and cancerous cells. Inside the cell, a chemical reaction takes place where a part of the cisplatin molecule is replaced by water, activating the compound.
Once activated, cisplatin targets the cell’s nucleus, where the genetic material, or DNA, is stored. The platinum atom in the cisplatin molecule binds strongly to specific sites on the DNA. This binding creates cross-links, which are abnormal bonds between different parts of the DNA strand or between two separate strands, creating distortions in the DNA’s double helix structure.
These structural changes in the DNA block the cellular machinery responsible for reading the genetic code and replicating the DNA. When the cell attempts to divide, it cannot accurately copy its damaged DNA, which halts cell division. This disruption triggers the cell’s internal surveillance systems, which recognize the irreparable damage. Consequently, the cell initiates a process called apoptosis, or programmed cell death, effectively eliminating the cancerous cell.
Cancers Treated With Cisplatin
Cisplatin is approved for the treatment of several types of cancer. It is a standard treatment for advanced testicular cancer, where its use has improved cure rates. The drug is also frequently used to treat advanced ovarian cancer, typically following surgery.
For patients with advanced bladder cancer, cisplatin is a foundational treatment. It is also a component of care for non-small cell lung cancer and small cell lung cancer. Other cancers treated with cisplatin include squamous cell carcinoma of the head and neck, cervical cancer, and certain types of lymphomas and sarcomas. Its application is tailored to the specific stage and type of cancer being treated.
In many protocols, cisplatin is not used as a standalone agent but is combined with other chemotherapy drugs. This approach, known as combination chemotherapy, can increase the effectiveness of the treatment by targeting cancer cells in different ways.
The Cisplatin Treatment Process
Cisplatin is administered directly into a vein through an intravenous (IV) infusion in a hospital or specialized clinic. Before the infusion begins, patients receive anti-nausea medications to prevent or reduce sickness.
A significant part of the treatment involves hydration. Patients are given large amounts of IV fluids before and after the cisplatin infusion. This extensive hydration is a protective measure for the kidneys, as cisplatin can be damaging to these organs. The extra fluids help dilute the drug and flush it through the kidneys more quickly, reducing the risk of injury.
Treatment is administered in cycles, with a rest period following each infusion to allow the body to recover. A common schedule might involve one infusion every three to four weeks. The infusion itself can last for several hours, as the drug must be given slowly with accompanying fluids.
Managing Common Side Effects
Managing the side effects of cisplatin is a part of the treatment plan. Common side effects include:
- Kidney damage (nephrotoxicity): This is a primary concern, prevented with the intensive IV hydration given during treatment. Patients are also encouraged to drink plenty of fluids at home to continue flushing the drug from their system.
- Nausea and vomiting: While historically severe, modern anti-emetic medications are highly effective at controlling these symptoms. Patients receive these before chemotherapy and are given prescriptions for home use. Eating small, frequent meals can also help.
- Nerve damage (peripheral neuropathy): This can develop over the course of treatment, causing numbness, tingling, or a pins-and-needles sensation in the hands and feet. This side effect is cumulative, so patients should report any new or worsening symptoms to their healthcare team.
- Hearing loss (ototoxicity): This may manifest as ringing in the ears (tinnitus) or difficulty hearing high-frequency sounds. Baseline and follow-up hearing tests may be conducted, and any changes should be reported to the medical team.
Monitoring During and After Treatment
Continuous monitoring is required to ensure patient safety and manage side effects. Before each treatment cycle, blood tests are performed to check kidney function by measuring levels of creatinine and blood urea nitrogen. These tests also monitor electrolyte levels, such as magnesium and potassium.
Blood cell counts are also closely watched. Cisplatin can suppress the bone marrow, leading to lower levels of white blood cells, red blood cells, and platelets. These counts help the medical team determine if it is safe to proceed with the next treatment. Depending on the risk of hearing-related side effects, hearing tests may be performed before treatment starts and at intervals throughout therapy.
After treatment is complete, long-term follow-up is necessary. Some side effects, like peripheral neuropathy, may persist for months or even years. Ongoing appointments allow for the management of lingering issues and for monitoring the treatment’s long-term effectiveness.