Cisplatin: Platinum-Based Cytostatic Agent for Curative Cancer Chemotherapy
Cisplatin is an inorganic platinum coordination compound that represents one of the most important cytostatic agents in oncology. First synthesized in the 1840s but not recognized for its anticancer properties until the 1960s by Barnett Rosenberg, cisplatin was introduced into clinical practice in the late 1970s and dramatically changed the prognosis of several malignancies, most notably testicular cancer, which became the first solid tumor to be cured in a significant proportion of patients with metastatic disease using combination chemotherapy containing cisplatin.
Despite the development of second-generation platinum compounds including carboplatin and oxaliplatin, which were designed to address some of cisplatin's toxicity limitations, cisplatin itself remains a cornerstone agent in numerous curative and palliative chemotherapy regimens. Its mechanism involves the formation of stable covalent crosslinks in DNA, leading to irreversible interference with DNA replication and transcription, and ultimately to apoptosis of rapidly dividing cancer cells. The distinctive and serious toxicity profile of cisplatin, particularly nephrotoxicity and ototoxicity, requires careful management protocols but does not preclude its essential role in modern oncology.
Mechanism of Action
Cisplatin enters cells via active transport through copper transporters (CTR1) and passive diffusion. Inside the cell, in the lower chloride concentration of the cytoplasm compared to extracellular fluid, cisplatin undergoes aquation: chloride ligands are replaced by water molecules, generating positively charged reactive platinum complexes. These electrophilic species react avidly with the N7 positions of purine bases (primarily guanine) in DNA. The most common adducts formed are intrastrand crosslinks between adjacent guanines (GG intrastrand crosslinks), which account for approximately 65 percent of platinum-DNA adducts, followed by intrastrand AG crosslinks and a smaller proportion of interstrand crosslinks between guanines on opposite DNA strands. These bulky DNA lesions distort the DNA double helix, preventing the separation of strands required for DNA replication and transcription. Cells attempt to repair these lesions through the nucleotide excision repair (NER) pathway; cisplatin resistance is partly mediated by upregulation of NER capacity. When repair fails or is insufficient, the persistent DNA damage triggers downstream signaling through ATM and ATR kinases, p53 activation, and ultimately apoptosis via caspase pathways. Cisplatin also generates reactive oxygen species and can induce mitochondria-mediated apoptosis pathways. The drug has no cell cycle phase specificity but is most toxic to rapidly dividing cells, which is the basis of its selectivity for tumor tissue over most normal tissues.
Indications
Cisplatin is a component of curative and standard-of-care chemotherapy regimens for numerous solid tumors. Its most important indication is testicular germ cell tumors, both seminomatous and non-seminomatous, where the BEP regimen (bleomycin, etoposide, cisplatin) achieves cure rates exceeding 90 percent even in patients with metastatic disease. This represents one of oncology's greatest therapeutic achievements. Non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) are treated with cisplatin-based doublets; in NSCLC, cisplatin combined with pemetrexed, gemcitabine, docetaxel, or vinorelbine forms the backbone of first-line platinum-based chemotherapy. Cisplatin-based chemoradiation is the standard of care for locally advanced cervical cancer, head and neck squamous cell carcinoma (HNSCC), and locally advanced bladder cancer. Bladder cancer (urothelial carcinoma) is treated with MVAC (methotrexate, vinblastine, doxorubicin, cisplatin) or GC (gemcitabine/cisplatin) in the metastatic setting, and neoadjuvant cisplatin-based chemotherapy improves survival in muscle-invasive disease. Ovarian cancer standard of care includes carboplatin/paclitaxel (carboplatin replacing cisplatin for tolerability), but cisplatin-containing regimens are used in specific situations. Cisplatin is also used in esophageal, gastric, and hepatocellular carcinoma treatment protocols.
Dosage and Administration
Cisplatin is administered exclusively by intravenous infusion; it must never be given orally or by any other route. Standard doses vary by regimen and indication, typically ranging from 50 to 100 mg per square meter of body surface area per cycle, administered as a single dose or split over several days every 3 to 4 weeks. In some regimens such as weekly cisplatin during concurrent radiotherapy, lower weekly doses of 30 to 40 mg per square meter are used. Preparation and administration require dilution in saline (sodium chloride 0.9%; glucose-containing solutions must not be used as they reduce cisplatin stability) and infusion over 1 to 4 hours through a patent peripheral or central venous line. Mandatory hyperhydration is a prerequisite for cisplatin administration to protect against nephrotoxicity. Patients receive intravenous saline infusion of at least 1 to 2 liters before cisplatin and continued hydration (often with mannitol or furosemide to maintain urine output) for several hours after cisplatin infusion, depending on the protocol. Antiemetic prophylaxis with a 5-HT3 antagonist (ondansetron, granisetron), a neurokinin-1 receptor antagonist (aprepitant), and dexamethasone is standard and essential given the severe emetogenicity of cisplatin. Administration must be performed in an oncology center by trained staff under established cytostatic handling protocols.
Side Effects
Cisplatin has one of the most challenging toxicity profiles of any cytostatic agent, with several severe and potentially irreversible adverse effects requiring careful monitoring and management. Nephrotoxicity is the dose-limiting toxicity of cisplatin. Cisplatin accumulates in renal tubular cells, causing oxidative damage, mitochondrial dysfunction, and tubular cell apoptosis. Without adequate hydration protocols, acute kidney injury can develop; even with hyperhydration, cumulative renal function decline occurs with repeated cycles. Serum creatinine, eGFR, and electrolytes (particularly magnesium and potassium) must be monitored before each cycle. Cisplatin-induced hypomagnesemia from renal wasting can persist for months after treatment completion. Ototoxicity is another serious and potentially irreversible toxicity. Cisplatin damages the outer hair cells of the cochlea, particularly those responsible for high-frequency hearing. Sensorineural hearing loss begins in the high-frequency range and can progress to affect speech frequencies with cumulative exposure. Audiometric monitoring is recommended, especially in pediatric patients where hearing loss has profound developmental consequences. Ototoxicity is not reliably prevented by any current intervention, though sodium thiosulfate has been studied as a protective agent in specific settings. Nausea and vomiting are among the most severe chemotherapy-induced gastrointestinal toxicities; cisplatin has the highest emetogenicity class, and inadequate antiemetic prophylaxis leads to debilitating acute and delayed emesis. Peripheral neuropathy, manifesting as numbness, tingling, and loss of vibration sense in the hands and feet, develops with cumulative cisplatin exposure and can be dose-limiting; it may partially recover after treatment completion but can be permanent. Myelosuppression, particularly anemia and thrombocytopenia, occurs and requires monitoring. Alopecia is a common but reversible effect.
Interactions
Concurrent use of nephrotoxic agents, including aminoglycoside antibiotics, amphotericin B, NSAIDs, and contrast media, substantially increases the risk of cisplatin-induced renal damage and should be avoided or carefully managed with additional monitoring and hydration. Loop diuretics such as furosemide are frequently used as part of cisplatin hydration protocols to maintain urine output, but they can exacerbate cisplatin-induced hearing loss and must be used carefully in this context. Concurrent use of ototoxic drugs such as aminoglycosides or vancomycin potentiates cisplatin ototoxicity. Myelosuppressive agents including other cytostatics, immunosuppressants, and radiation therapy have additive bone marrow suppressive effects. Anticoagulation with warfarin may be affected during cisplatin-containing chemotherapy, with INR fluctuations requiring close monitoring. Live vaccines are contraindicated during cisplatin-containing chemotherapy due to immunosuppression. Antiepileptic drugs such as valproate and phenytoin may have reduced serum concentrations when co-administered with cisplatin-based chemotherapy due to altered absorption or increased renal clearance, requiring therapeutic drug monitoring.
Special Notes
Cisplatin is a cytotoxic hazardous drug requiring appropriate protective equipment during preparation and administration. It is subject to strict cytostatic waste disposal regulations. Before each cycle, comprehensive assessment including renal function (serum creatinine, eGFR), electrolytes (magnesium, potassium), complete blood count, audiometry (for patients receiving multiple cycles, especially in pediatric oncology), and a careful history for neurological symptoms is mandatory. Cisplatin is absolutely contraindicated in patients with pre-existing severe renal impairment, dehydration, or unresolved electrolyte abnormalities before the planned cycle. A carboplatin-based regimen may be substituted in patients ineligible for cisplatin due to renal insufficiency, hearing impairment, or neuropathy, accepting that carboplatin may be less active in some settings. Long-term follow-up of cisplatin-treated patients should include monitoring for renal function, hypomagnesemia, hearing, neuropathy, and gonadal function (particularly relevant in testicular cancer survivors of reproductive age). Second malignancies, particularly leukemias, have been observed in long-term survivors of cisplatin-based chemotherapy, reflecting the genotoxic mechanism of platinum compounds.
Related Topics
Frequently Asked Questions
Why is mandatory hyperhydration required before cisplatin administration?
Cisplatin is concentrated by the kidneys during renal excretion and accumulates in proximal tubular cells, where it causes direct oxidative damage, mitochondrial injury, and apoptosis of tubular epithelium. This tubular toxicity is the primary mechanism of cisplatin-induced nephrotoxicity. Aggressive intravenous hydration before and after cisplatin infusion dilutes the drug concentration in the tubular fluid, reduces the time cisplatin spends in contact with tubular cells, and maintains a high urine flow rate that washes the drug through more rapidly. Without this hydration, acute tubular necrosis and significant kidney damage can occur even after a single cycle. Mannitol is sometimes added to induce osmotic diuresis, further reducing tubular exposure. Despite these measures, cumulative renal function decline occurs in many patients over multiple cycles, and renal function must be formally assessed before each cisplatin administration to determine whether the patient can safely receive the next dose.
How did cisplatin transform the treatment of testicular cancer?
Before the introduction of cisplatin-based combination chemotherapy in the late 1970s, metastatic testicular cancer was nearly uniformly fatal. The landmark work of Lawrence Einhorn and colleagues demonstrated that the BEP regimen (bleomycin, etoposide, cisplatin) could cure the majority of patients with advanced metastatic germ cell tumors. Today, even patients with disseminated metastatic testicular cancer achieve cure rates exceeding 70 to 90 percent depending on prognostic risk category. This transformation of a lethal malignancy into a curable disease represents one of the most significant advances in cancer medicine of the 20th century and established cisplatin as a foundational chemotherapy agent. The success in testicular cancer stimulated extensive research into cisplatin's use in other solid tumors, leading to its widespread adoption across multiple cancer types.
Is hearing loss from cisplatin permanent?
Cisplatin-induced ototoxicity is typically irreversible. The drug destroys the outer hair cells of the organ of Corti in the cochlea, particularly in the basal turn responsible for high-frequency sound perception. These hair cells do not regenerate in mammals. Hearing loss begins in the high-frequency range (4000 Hz and above) and with increasing cumulative dose can progress to affect lower frequencies relevant to speech understanding. The risk is higher with increasing cumulative cisplatin dose, in younger patients (especially children), in patients with pre-existing hearing impairment, and when ototoxic drugs such as aminoglycosides are co-administered. Audiometric monitoring during cisplatin therapy allows early detection of hearing changes and may prompt dose modification or switching to carboplatin in borderline cases. Research into otoprotective agents continues; sodium thiosulfate shows promise in reducing ototoxicity in pediatric patients with localized tumors when the agent can be given after cisplatin without interfering with its anticancer efficacy.
Sources
- Einhorn LH. Curing metastatic testicular cancer. Proc Natl Acad Sci USA. 2002.
- Dasari S, Tchounwou PB. Cisplatin in cancer therapy: molecular mechanisms of action. Eur J Pharmacol. 2014.
- EMA: Cisplatin Summary of Product Characteristics, current version.