What You Need to Know About Cancer Treatment Drugs

Cancer drugs central to treatment for for cancer . Today, oncologists use chemotherapy, targeted therapy, and immunotherapy, to treat cancer based on each patient’s disease condition.

Advances in medical science have expanded the range of available cancer drugs, allowing treatment to be precisely tailored according to the cancer type, stage of cancer, and the patient’s overall health.

This guide explains the “ABCs” or basics of cancer drugs, how they function, and how they are selected as part of cancer care today.

Key Takeaways

Cancer drugs include chemotherapy, targeted therapy, immunotherapy and hormonal therapy.
Each type of drug works differently to control or eliminate cancer cells by entering the bloodstream to target cancer cells in the body.
Treatment plans are personalised based on the tumour biology and patient’s overall health.
Side effects vary depending on the medication used.
Careful monitoring ensures safety and effectiveness throughout the cancer treatment journey.

What Are Cancer Drugs?

Cancer drugs are medications used to treat cancer by killing cancer cells, slowing their growth, or preventing them from spreading. Cancer drugs may be used:

As the main treatment
Before surgery (neoadjuvant therapy)
After surgery (adjuvant therapy)
Together with radiation therapy
To control advanced or metastatic disease

Modern oncology increasingly relies on understanding the biological characteristics of each tumour. This allows doctors to select the most appropriate class of cancer drugs for each patient.

A: Chemotherapy

Chemotherapy is one of the most established forms of anti-cancer drugs.

How Chemotherapy Works

Chemotherapy targets rapidly dividing cells. Since cancer cells divide more quickly than most normal cells, they are particularly sensitive to these medications.

However, some healthy cells that divide quickly, such as those in hair follicles, the digestive tract and bone marrow may also be affected during chemotherapy treatment. This can cause side effects such as hair loss, nausea, loss of appetite and risk of infection.

When Chemotherapy Is Used

Chemotherapy may be used:

To shrink tumours before surgery
To eliminate remaining cancer cells after surgery
In combination with radiation therapy
To slow the progression of advanced cancers

Common Side Effects

Because chemotherapy affects rapidly dividing cells, side effects may include:

Fatigue
Hair loss
Nausea
Loss of appetite
Increased risk of infection

These side effects are closely monitored by the care team and are usually temporary.

B: Targeted Therapy

Targeted therapy are cancer drugs that more precisely target the specific type of cancer cells.

How Targeted Therapy Works

Unlike chemotherapy, which broadly affects rapidly dividing cells , targeted therapy focuses on specific molecular changes within cancer cells.

Cancer cells often carry abnormal proteins or genetic mutations that drive growth. Targeted drugs are designed to block these specific pathways.

Examples include the following:

HER2-Positive Breast Cancer

In patients whose breast cancer overexpresses the Human Epidermal Growth Factor 2 (HER2) receptor targeted therapy such as trastuzumab may be used. This cancer drug binds to HER2 receptors on cancer cells and is often given together with chemotherapy.

For example, a patient diagnosed with early-stage HER2-positive breast cancer may receive trastuzumab after surgery to reduce the risk of recurrence. In more advanced cases, it may be combined with other targeted or chemotherapy drugs as part of a structured treatment plan.

Chronic Myelogenous Leukaemia (CML)

In CML, the target is tyrosine kinase, which is the protein produced by the BCR-ABL mutated gene. Target therapy drugs called tyrosine kinase inhibators such as Imatinib block the BCR-ABL protein and are commonly prescribed as long-term oral therapy.

A patient newly diagnosed with CML may be prescribed daily oral imatinib after genetic testing confirms the mutation. Regular blood monitoring helps cancer doctors assess the response and adjust treatment if necessary.

Melanoma

For certain advanced melanomas, immunotherapy drugs such as pembrolizumab may be recommended. These cancer drugs help the immune system recognise and attack cancer cells more effectively.

For instance, when surgery alone is not sufficient to treat metastatic melanoma, the patient may receive immunotherapy as the primary treatment. Treatment response is monitored through imaging and clinical assessment over time.

Lung Cancer with EGFR Mutation

EGFR mutation lung cancer is driven by mutations in the Epidermal Growth Factor Receptor gene. Patients with this type of lung cancer may receive EGFR inhibitors such as osimertinibafter molecular testing confirms the mutation.

In real-world settings, a patient diagnosed with advanced non-small cell lung cancer may undergo tumour genetic testing. If an EGFR mutation is identified, a targeted oral cancer drug may be prescribed instead of conventional chemotherapy.

Benefits and Limitations of Targeted Therapy

Targeted therapy may:

Cause fewer side effects compared to traditional chemotherapy
Be more effective in cancers with specific mutations

However, not all cancers have identifiable targets, and drug resistance may develop over time.

Side effects vary depending on the pathway targeted and may include skin changes, diarrhoea or liver function abnormalities.

C: Immunotherapy

Immunotherapy is a novel type of therapy that works differently from chemotherapy and targeted therapy.

How Immunotherapy Works

Immunotherapy stimulates or activates the body’s own immune system to recognise and attack cancer cells.

Normally, cancer cells can evade immune detection. Immunotherapy drugs help to remove this “shield,” allowing immune cells to identify, target and attack thecancer cells more effectively.

Checkpoint inhibitors are one example of immunotherapy.

Who May Benefit

Immunotherapy may be used to treat cancers, including:

Lung cancer
Melanoma
Triple-negative breast cancer (TNBC)
Kidney cancer

However, effectiveness depends on the tumour characteristics and immune markers.

Side Effects

Because immunotherapy activates the immune system, side effects that may result from immune overactivity include :

Skin rash
Fatigue
Inflammation of organs (e.g., lungs, liver)

These side effects are closely monitored and managed by the cancer doctor.

D: Hormonal Therapy

Some cancers are driven by hormones.

Hormonal therapy is a category of cancer drugs used in cancers such as:

Breast cancer
Prostate cancer

These drugs work by:

Lowering hormone levels
Blocking hormone receptors to slow or stop cancer growth

Side effects may include hot flushes, mood changes, bone thinning or sexual health changes.

E: Combination Therapy

In many cases, more than one class of cancer drug is used together.

Combination therapy may:

Improve effectiveness of treatment by targeting cancer cells through different mechanisms
Reduce the risk of drug resistance

The sequence of treatment using combination therapy is carefully planned by the cancer doctor.

How Doctors Choose Cancer Drugs

Selecting the appropriate cancer drug for a patient depends on several factors:

Cancer type and stage
Genetic and molecular characteristics of the cancer
Patient’s age, general health and other medical conditions
Treatment goals (curative vs palliative)

Personalised medicine plays an increasingly important role, with molecular testing of tumour tissue helping to guide treatment decisions.

Monitoring During Treatment

Patients receiving cancer drugs undergo regular monitoring to assess:

Response to treatment
Blood count
Organ function
Side effects

This ensures safety and efficacy of treatment and allows the treating doctor to make adjustments when necessary.

Understanding Treatment Goals

Cancer drugs may be prescribed to achieve different treatment goals:

To cure the disease
To control the disease
For symptom relief
To prolong survival
Improve quality of life

Discussion with your care team helps to align treatment decisions with the treatment goals.

Managing Side Effects

Each category of cancer drugs can cause different side effects . Supportive care to manage side effects for patients receiving cancer drugs may include:

Anti-nausea medications
Growth factor injections
Nutritional support
Hormone management
Immune-related side effect management

Close monitoring by the care team allows prompt intervention if the patient experiences side effects.

Looking Ahead: Advances in Cancer Drugs

Research continues to expand the range of available cancer drugs. New developments include:

Precision medicine guided by genomic testing
Antibody-drug conjugates that target specific cancer antigens to kill tumour cells
Personalised vaccine approaches
Next-generation immunotherapy

Ongoing clinical trials contribute to advancing cancer treatment options.

A Collaborative Approach

Cancer treatment involves multi-disciplinary planning from the care team which includes :

Medical oncologists
Radiation oncologists
Surgeons
Radiologists
Nurses
Pharmacists

This team-based approach ensures that cancer drugs prescribed are safe and effective.

If you have questions about your treatment plan, speak with your NCCS care team for personalised guidance.

Frequently Asked Questions

Are cancer drugs always given through an intravenous drip?
No. Some cancer drugs are administered intravenously, while others are taken orally as tablets or capsules. How the cancer drug is administered depends on the type of medication.
Can cancer drugs stop working over time?
Yes. Some cancers develop resistance to certain drugs over time. If this occurs, doctors may adjust the treatment plan or change prescribed cancer drug treatment.
Are newer cancer drugs always better than older ones?
Not necessarily. The most appropriate drug depends on cancer type, molecular features and the patient’s overall health. Established treatments remain highly effective in many cases.
Can I continue taking other medications while on cancer drugs?
Always inform your doctor about all medications and supplements that you are taking as some drugs may interact or interfere with the efficacy of the prescribed cancer treatment.
Will I need cancer drugs for the rest of my life?
The duration a patient needs cancer drugs depends on the cancer type and treatment goals. Some therapies are given for a defined number of cycles, while others may be continued longer under monitoring from the care team.
How are cancer drugs administered?
Cancer drugs may be given intravenously through a drip, taken orally as tablets or capsules, injected under the skin, or delivered through specialised infusion devices. The method depends on the specific cancer drug and treatment plan.
What are the most common side effects of cancer drugs?
Side effects vary depending on the class of cancer drug. Chemotherapy may cause hair loss nausea and fatigue . Targeted therapy may cause skin or liver changes. Immunotherapy may lead to immune-related inflammation. Most side effects are manageable with close monitoring and intervention from the care team.
How do cancer drugs work in the body?
Different cancer drugs work through different mechanisms. Some destroy rapidly dividing cells, others block specific genetic mutations, and some enhance the immune system’s ability to detect and kill cancer cells.
What is the cost of cancer drugs?
The cost of cancer drugs varies depending on the type of medication, treatment duration, and healthcare coverage. Financial counselling by the healthcare provider can provide guidance on insurance coverage, subsidies and assistance programmes where applicable.
What’s the difference between chemotherapy and immunotherapy drugs?
Chemotherapy directly targets rapidly dividing cells, including cancer cells. Immunotherapy works by stimulating the immune system to recognise and attack cancer cells. They act through different biological mechanisms.