Most gastric cancer patients will have such concerns after surgery and before receiving chemotherapy: chemotherapy can cure but hurt, does chemotherapy mean no food, vomiting and hair loss? The actual fact is not, although chemotherapy drugs in killing tumor cells will also cause damage to the body’s normal cells, chemotherapy process will inevitably have some adverse reactions, but chemotherapy adverse reactions vary from person to person, and through active prevention and symptomatic treatment, the majority of patients can tolerate.
What are the common adverse reactions to adjuvant chemotherapy after gastric cancer surgery, including oxaliplatin, capecitabine, tegeo (S-1), cisplatin, etc.? How to prevent, monitor and manage them? The answers to each of these questions follow.
Adverse reactions common to chemotherapy drugs
Bone marrow suppression
The common drugs used in postoperative adjuvant chemotherapy for gastric cancer may cause varying degrees of myelosuppression, which is one of the most common adverse reactions. About 80% of patients will experience myelosuppression during tumor radiotherapy, mainly in the form of decreased white blood cells, thrombocytopenia, and anemia. Usually, leukopenia starts 1 week after chemotherapy discontinuation and reaches its lowest point by 10-14 days after discontinuation, and then rebound slowly after 2-3 days at low level and return to normal by day 21-28. The platelet drop occurs slightly later than the leukocyte drop, also dropping to a minimum in about 2 weeks, and it declines rapidly, rebounding quickly after a short stay at the minimum. The red blood cell decline occurs much later.
When leukocytes are reduced, the physician will decide whether to apply symptomatic treatment with human granulocyte colony-stimulating factor depending on the degree of reduction, and will look for signs of infection and aggressive anti-infective therapy if infection is present. If platelets are reduced, attention should be paid to the tendency of bleeding, and the patient should avoid bumps and falls, hard foods, and constipation, etc. If necessary, platelet transfusion, recombinant human interleukin-11, and recombinant human thrombopoietin will be administered. In addition, when hemoglobin decreases, anemia may occur, and recombinant human erythropoietin may be used, and in severe cases, red blood cells may be transfused.
Patients need to have their blood count reviewed once or twice a week during postoperative adjuvant chemotherapy, and inform their physician if they develop bone marrow suppression, who will increase the frequency of blood tests and treat the symptoms.
Gastrointestinal reactions
Gastrointestinal reactions are one of the most common adverse effects of chemotherapy, and most patients experience varying degrees of gastrointestinal reactions after the drug is administered. The doctor will routinely give prophylactic antiemetic drugs before chemotherapy for nausea and vomiting, and the patient’s diet after chemotherapy should be based on a light diet, with fewer meals and avoiding spicy, strong-tasting or greasy foods.
When diarrhea occurs, take antidiarrheal medication as prescribed by the doctor. For more frequent diarrhea and the elderly and frail, the doctor will pay attention to energy and fluid replacement to maintain water and electrolyte balance and prevent dehydration.
To avoid constipation during medication, patients can drink more water and eat fiber-rich foods. Appropriate activity will promote gastrointestinal motility, and stool softeners such as lactulose and aloe vera capsules can be used to promote bowel movements if necessary.
In addition, during chemotherapy, it is also important to keep the mouth clean and moist, and to gargle with saline or rehabilitative solution in case of oral mucositis.
Adverse effects specific to different postoperative adjuvant chemotherapy drugs
Oxaliplatin
One of the more obvious adverse reactions to oxaliplatin is neurotoxicity, which falls into two main categories.
- Acute toxic reactions Transient acute neurotoxicity can occur in approximately 85% to 95% of patients, manifesting as rapid onset sensory nerve abnormalities, such as distal limb or perioral sensory abnormalities, in addition to acute pharyngeal sensory deficits resulting in difficulty breathing and swallowing in 1% to 2% of patients. Acute neurotoxicity occurs within minutes or hours after infusion of oxaliplatin or within 1-2 days after administration; cold stimulation is the main trigger, and patients often have symptoms triggered or exacerbated by exposure to metal products, cold water, etc.; however, it is usually self-limiting and tends to resolve on its own within a few days.
- Chronic toxic reactions usually occur after multiple cycles of oxaliplatin, with an incidence of 68% to 98%. Patients initially present with sensory numbness and sensory abnormalities in the extremities, which can be severe enough to interfere with life, with motor nerve dysfunction such as the inability to button, write, or hold chopsticks. As the treatment cycle increases, the above symptoms will gradually worsen, which is called “cumulative dose and accumulative toxicity”. Unlike acute toxic reactions, chronic neurotoxicity of oxaliplatin is not triggered or exacerbated by exposure to cold.
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There is no need to panic when these symptoms occur. The neurotoxicity of oxaliplatin is reversible, and studies have now shown that neurological function can be restored in 75% of patients within 3 to 5 months of treatment discontinuation.
In view of the fact that oxaliplatin neurotoxicity is exacerbated by cold, patients should be careful to keep warm throughout treatment, especially in winter, not to eat cold food or drink cold water, and try to wash hands and feet with warm water, drink warm water, wear cotton gloves, and wear a mask. The company’s main goal is to provide the best possible service to its customers.
Capecitabine
A more common adverse reaction to capecitabine is hand-foot syndrome, with an incidence of about 45% to 68%. The skin on the hands and feet is often pruritic, numb, and sluggish, with erythema, swelling, and pain, and a few patients may have skin breakdown, blistering, desquamation, or even ulceration of the extremities with secondary infection, and in severe cases, they may be unable to walk or care for themselves because of severe pain.
Patients should pay attention to keeping the skin clean and moist during the application of capecitabine, protect it from cold and frost, wear soft and loose shoes and socks and gloves to prevent rubbing and breaking; avoid contact with chemical detergents such as washing powder and soap. Once the hand-foot syndrome occurs, you should promptly inform your doctor, who will treat the symptoms and give a discontinuation or dose reduction plan depending on the severity of the symptoms.
It is important to note that capecitabine can induce cardiotoxicity, causing acute coronary syndrome, arrhythmias, cardiogenic shock, and even sudden death. In one study, the average incidence of cardiac events with capecitabine, either alone or in combination with other drugs, was 34.6%, and 32.6% of patients had ECG changes, including prolonged PR intervals and QT intervals. During drug administration, patients need to have regular follow-up electrocardiograms and cardiac ultrasounds to monitor for cardiac injury. For those with underlying cardiac disease, physicians may choose a non-cardiotoxic drug [such as Raltitrexed] to avoid exacerbating cardiac injury, depending on the circumstances.
Cisplatin
Cisplatin is a first-generation platinum drug, and typical adverse effects include nephrotoxicity and ototoxicity in addition to severe gastrointestinal reactions. During dosing, the physician will administer hydration therapy (usually a large infusion of fluid), and patients should also drink plenty of water to promote urination to reduce nephrotoxicity and monitor renal function after dosing. Some patients experience high-frequency hearing loss and tinnitus after cisplatin application, and should inform their physician when these occur.
In addition to “talking about cancer,” many patients are now “talking about therapy. The first time I saw this, I was able to get to the top of the list, and I was able to get to the bottom of the list. Patients and their families should communicate with their doctors at all times during the drug administration, and let them make scientific assessment and symptomatic treatment when adverse reactions occur, and decide whether the chemotherapy drug needs to be reduced or discontinued. (Contributed by Yanwen Diao, Department of Medical Oncology, The First Affiliated Hospital of China Medical University)