Chemotherapy (often shortened to chemo) uses drugs to kill cancer cells or stop them from dividing. It is a systemic treatment. Since it was introduced in the mid-20th century, chemotherapy has been one of the pillars of cancer treatment — even today, with the rise of targeted therapy and immunotherapy, it remains an indispensable foundation in many cancer treatment plans.
Many people are terrified by the thought of chemotherapy, picturing severe vomiting and weakness. In fact, modern management of chemotherapy side effects has improved greatly. With anti-nausea medications and supportive care, many patients can maintain a life close to normal. Understanding it is the first step to letting go of fear.
How It Works
Cancer cells are characterized by rapid division. Chemotherapy drugs target exactly this feature: they interfere with different stages of cell division — some damage DNA replication, others block the formation of the skeleton needed for cell division — preventing rapidly dividing cancer cells from multiplying and eventually causing them to die.
Because the drugs target cells that divide quickly, normal cells in the body that also divide rapidly (hair follicles, oral and intestinal mucosa, bone marrow blood-forming cells) are also affected. This is why side effects such as hair loss, mouth ulcers, and low blood counts occur. The combination and scheduling of different chemotherapy drugs are designed to strike a balance between killing cancer and allowing normal cells to recover.
When It Is Used
Chemotherapy plays different roles at different stages: preoperative (neoadjuvant) chemotherapy shrinks the tumor first to improve the success rate of surgery; postoperative (adjuvant) chemotherapy clears any remaining cancer cells to reduce the risk of recurrence; for advanced cancer, chemotherapy aims to control the disease, prolong survival, and relieve symptoms.
For blood cancers such as leukemia and lymphoma, chemotherapy is the mainstay of curative treatment. Whether to use chemotherapy and which combination to use depends on the cancer type, stage, physical condition, and genetic test results — for example, some patients with early breast cancer can avoid chemotherapy after a gene expression test confirms that the benefit would be limited.
Common Side Effects and How to Manage Them
Nausea and vomiting are the side effects people worry about most, but modern anti-nausea medications (such as 5-HT3 antagonists and NK1 antagonists) can effectively prevent most vomiting. The key is to take them "preventively" as prescribed, rather than waiting until you vomit. Bone marrow suppression (low white blood cells) increases the risk of infection: a fever above 38 degrees requires immediate medical attention — this is the most important safety rule during chemotherapy.
Other common issues: hair loss usually regrows after treatment, so you can prepare a wig or headscarf in advance; mouth ulcers can be relieved with a doctor-prescribed mouthwash; fatigue is best managed with regular routines and light exercise; some drugs cause numbness in the hands and feet (peripheral neuropathy) or diarrhea and constipation — all of these should be reported to your medical team so they can adjust. Almost every side effect has a corresponding management approach, so do not suffer in silence.
Lifestyle Tips During Treatment
There is no need to blindly restrict your diet: balance, thoroughly cooked food, and hygiene are the principles. When white blood cells are low, avoid raw food and unpasteurized dairy products. Eating small, frequent meals can help with poor appetite. Moderate exercise (such as walking) actually helps reduce fatigue — you do not need to stay in bed.
Pay attention to infection prevention in daily life: wash your hands frequently, wear a mask in crowded places, and avoid contact with friends or family who have colds. Mental health matters too — chemotherapy is a marathon, not a sprint. Staying connected with family and friends and seeking psychological support when needed are all part of the treatment journey.
Clinical Trials: One More Treatment Option
Chemotherapy itself is constantly evolving: new drug combinations, improved formulations (such as albumin-bound drugs), and combination strategies of chemotherapy with targeted therapy and immunotherapy are all validated through clinical trials before becoming standard. Patients who join trials are often among the first to benefit from these improvements.
The CancerLink platform can screen for clinical studies currently recruiting in Hong Kong based on cancer type, stage, and genetic mutations. Once successfully matched and enrolled, study-related treatment costs are fully covered. To learn about current trial options, please visit the study recruitment page.
Chemotherapy is not a monster — it is a mature treatment refined over decades. Speak up about every side effect and ask clearly about every instruction, and you will find this journey easier than you imagined.