Chemotherapy, often abbreviated to “chemo,” refers to a category of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents) as part of a standardized chemotherapy regimen. It is considered a systemic therapy, which means it targets cancer cells throughout the body, unlike localized treatments like surgery or radiation therapy, which target specific areas.

What is Chemotherapy?

Chemotherapy utilizes chemical substances to kill rapidly dividing cells, a common characteristic of cancer cells. While it is most commonly associated with cancer treatment, chemotherapy can also be used to treat certain other conditions, such as bone marrow diseases and immune system disorders.

How Does Chemotherapy Work?

Chemotherapeutic agents target cells at different phases of the cell cycle, aiming to eradicate cancer cells while causing the least possible damage to normal cells. However, because these drugs circulate throughout the body, they can affect both cancerous and healthy cells, particularly those that also divide rapidly under normal circumstances, such as cells in the bone marrow, digestive tract, and hair follicles.

Types of Chemotherapy

  1. Adjuvant chemotherapy: This is given after primary treatments like surgery to destroy any remaining cancer cells, reducing the risk of cancer recurrence.
  2. Neoadjuvant chemotherapy: Administered before the main treatment (such as surgery), it aims to shrink tumors to facilitate more effective subsequent treatments.
  3. Palliative chemotherapy: This type is used to alleviate symptoms and improve the quality of life for patients with advanced cancer.

Chemotherapy Administration

Chemotherapy can be delivered through various methods, including oral (pills or liquids), intravenous (injected into a vein), intramuscular (injected into a muscle), and intraperitoneal (delivered directly into the abdominal cavity), among others. The method of administration often depends on the specific drug and the type of cancer.

Side Effects of Chemotherapy

Due to its systemic nature and the way it targets rapidly dividing cells, chemotherapy can lead to a range of side effects, which vary depending on the drugs used, the dosage, and the individual patient. Common side effects include:

  • Fatigue
  • Nausea and vomiting
  • Hair loss
  • Increased risk of infections (due to reduced white blood cell counts)
  • Anemia (due to reduced red blood cell counts)
  • Bruising or bleeding (due to reduced platelet counts)
  • Mucositis (inflammation of the lining of the digestive tract)

Managing Side Effects

Ongoing research aims to find ways to reduce chemotherapy’s side effects. Strategies include using targeted therapies that more selectively attack cancer cells, administering supportive care medications to counteract side effects, and employing personalized medicine approaches to choose the most effective and least toxic chemotherapeutic agents for each patient.

The Future of Chemotherapy

The landscape of cancer treatment is evolving, with advancements in targeted therapy, immunotherapy, and precision medicine complementing traditional chemotherapy. Researchers are working to develop drugs that are more effective and have fewer side effects, improving the quality of life for patients undergoing cancer treatment.


Chemotherapy remains a cornerstone of cancer treatment, playing a crucial role in curative, adjuvant, neoadjuvant, and palliative care settings. Despite its challenges, including side effects and the emergence of drug resistance, ongoing research and development are expanding our understanding and improving the efficacy of chemotherapy.