Currently, the National Comprehensive Cancer Network (NCCN) guidelines recommend chemotherapy agents commonly used for gastric cancer, including paclitaxel [Paclitaxel, Docetaxel], platinum [Cisplatin, Oxaliplatin Oxaliplatin], antimetabolites [Fluorouracil, Capecitabine, S-1], Irinotecan, etc. What are the characteristics of these drugs? What adverse effects may they cause? The following will be described.
Paclitaxel
The paclitaxel class includes paclitaxel, docetaxel, and others. Because paclitaxel is extremely poorly soluble in water, it is applied with a co-solvent, but this co-solvent may lead to adverse reactions such as allergic reactions and neurotoxicity. Docetaxel also requires a co-solvent when applied, and there is a risk of significant allergic reactions. Therefore, anti-allergic drugs need to be taken in advance before the use of paclitaxel, and cardiac monitoring should be performed during the drug administration in addition to the continued use of anti-allergic drugs for the timely detection of possible anaphylaxis. In addition to allergic reactions, bone marrow suppression, nausea, vomiting, and neurotoxicity are also common side effects of paclitaxel drugs.
Platinums
Platinums are the metal platinum complexes commonly used in chemotherapy today. The first-generation platinum drug cisplatin is a first-line agent for many solid tumors and can be used as a radiosensitizer (applied concurrently with radiotherapy to increase the efficacy of radiotherapy) with better efficacy, a broad antitumor spectrum, and is less expensive. Cisplatin has an important position among chemotherapeutic drugs as a model of high efficiency and high toxicity. The myelosuppressive effect of cisplatin is mild, but it can cause more severe nausea and vomiting, and patients usually need to use strong antiemetics. In particular, cisplatin is nephrotoxic and ototoxic, both of which are related to the dose, but cisplatin is often administered in large doses for short periods at a time. （Cisplatin should not be used in combination with aminoglycoside antibiotics [Streptomycin, Gentamicin, etc.]. High-dose cisplatin therapy (greater than 80-120 mg/m daily) requires hydration (usually large amounts of fluids and fluids) to protect the kidneys.
Oxaliplatin, also known as platinum oxalate, is a third-generation platinum-based anticancer agent. Oxaliplatin is less toxic than cisplatin, has no cardiotoxicity or ototoxicity, and is generally not nephrotoxic. The myelosuppressive effects of oxaliplatin are mild and usually result in nausea, vomiting and diarrhea, but are generally not severe. Acute sensory and motor nerve symptoms can be caused during injectable dosing, and patients should keep warm and avoid all kinds of cold stimuli for several days after treatment. With increasing doses of drug application, patients may experience mild to moderate neurotoxicity, manifesting as abnormal sensation in the extremities and, in more severe cases, difficulty with movement and writing, but may gradually recover after discontinuation of the drug.
Anti-metabolites
Fluorouracil, capecitabine, and S-1 [i.e., tegeo, a fluorouracil derivative containing tegafur, gimestat, and oteracil potassium] are all commonly used antimetabolite chemotherapeutic agents for gastric cancer.
- Fluorouracil is the most widely used antitumor drug and has an important role in medical oncology treatment. The main side effects are gastrointestinal reactions, bone marrow suppression, stomatitis (mouth ulcers), alopecia, and phlebitis. Because fluorouracil is highly irritating to the veins and usually requires continuous intravenous infusion, it can lead to more severe phlebitis, which manifests as redness and pain in the venous vessels, followed by darkening and hardening of the vessels and black dendritic changes in the skin. This side effect can be avoided in patients with central venous placement.
- S-1 is a combination of tegafur, gemini, and otelacil potassium, which is slowly converted to 5-fluorouracil in the body after oral administration to exert antitumor effects, so most side effects are the same as those of fluorouracil.
- Capecitabine is an oral drug that is converted into fluorouracil to exert antitumor effects in the body, so most of the side effects are the same as those of fluorouracil, but more specifically, skin reactions: the chance of developing hand-foot syndrome after drug administration is close to 50%, mainly manifesting as numbness, dullness, abnormal sensation, tingling, no pain or pain in the palms and soles of the feet, skin swelling or erythema, flaking, blistering, or severe pain. or severe pain. Patients can take oral vitamin B6 (Vitamin B6) and celecoxib (Celebrex) during the course of medication. Keeping the skin of the hands and feet moist and reducing irritation from overheating, water immersion, and pressure can reduce symptoms and promote recovery.
Topoisomerase inhibitors
Iritecan is a topoisomerase I inhibitor that inhibits cell growth. A common adverse effect is delayed diarrhea (occurring 24 hours after dosing), with the median time to first loose stool being day 5 after dosing. Once the first loose stool occurs, the patient should start drinking plenty of electrolyte-containing beverages and should inform the physician immediately for appropriate treatment.
Currently, the recommended antidiarrheal treatment is high-dose loperamide. Acute cholinergic syndrome is also a common side effect, with symptoms such as early-onset diarrhea, abdominal pain, conjunctivitis, rhinitis, sweating, miosis, tearing, and increased salivation that may occur within the first 24 hours of dosing and may resolve with atropine treatment. In addition to diarrhea, bone marrow suppression, nausea, and vomiting are common side effects of irinotecan.
Actively understand the common adverse effects of various chemotherapy drugs, communicate more with your doctor, and follow medical advice to prevent and actively manage complications so that you can better complete your treatment related to gastric cancer. (Contributed by Xiaoyu Guo, Department of Gastrointestinal Oncology, The First Hospital of China Medical University)