Chemotherapy uses drugs to kill or stop cancer cells. Traditional cytotoxic classes target rapidly dividing cells, while newer targeted therapies and immunotherapies act on specific molecular pathways or the immune system. Oncologists balance dose and schedule to maximize effect and limit toxicity. Supportive care - antiemetics, growth factors, hydration, and fertility preservation - has improved tolerability and outcomes.

What chemotherapy is and where it began

Chemotherapy uses chemical drugs that kill or stop the growth of cancer cells. The first systemic chemotherapies - nitrogen mustards and folate antagonists - appeared in the 1940s. Since then, cancer drug development has grown into a large global industry and expanded beyond classic cytotoxic agents to include targeted and immune-based therapies.

How traditional chemotherapy works

Most traditional chemotherapy drugs interfere with cell division or DNA synthesis, so they preferentially affect rapidly dividing cancer cells. Because these drugs damage cells, they are described as cytotoxic. Some agents also trigger apoptosis (programmed cell death).

Common classes of conventional chemotherapy include:


  • Alkylating agents


  • Antimetabolites


  • Anthracyclines


  • Plant-derived agents (vinca alkaloids, taxanes)


  • Topoisomerase inhibitors


  • Antitumor antibiotics


Targeted drugs and immunotherapies


Since the early 2000s, treatments have expanded to include targeted therapies (for example, tyrosine kinase inhibitors such as imatinib for chronic myeloid leukemia and gastrointestinal stromal tumors) and immune-based therapies (immune checkpoint inhibitors and CAR-T cell therapies). These approaches act on specific molecular pathways or the immune system rather than broadly on cell division.

Dosing and administration

Oncologists calculate doses to balance effectiveness and toxicity. Historically clinicians use body-surface-area (BSA) calculations and nomograms, but modern dosing also considers organ function, drug interactions, pharmacogenomics, and sometimes fixed dosing. Most chemotherapy is given intravenously, but many newer agents are oral and administered at home.

Combination regimens remain common because using drugs with different mechanisms reduces the chance of resistance and can be more effective than single agents.

Side effects and supportive care

Chemotherapy affects healthy rapidly dividing tissues too. Common acute and subacute effects include nausea and vomiting, hair loss, mouth sores (mucositis), diarrhea or constipation, and myelosuppression (low blood counts) that raises infection risk. Some drugs cause long-term or organ-specific toxicities - cardiotoxicity (anthracyclines), neuropathy (platinum drugs, taxanes), hepatotoxicity, nephrotoxicity, and ototoxicity.

Supportive care has improved outcomes: modern antiemetics, growth factors (G-CSF) to reduce neutropenia, hydration protocols, and fertility preservation options are standard parts of treatment planning.

Conclusion

Chemotherapy remains a core tool in cancer care. Over the past decades, it has evolved from broadly cytotoxic drugs to a landscape that also includes targeted agents and immunotherapies. Treatment plans now personalize drug choice, dose, and supportive measures to maximize benefit and limit harm.

FAQs about Cancer Chemotherapy

How is chemotherapy different from targeted therapy or immunotherapy?
Chemotherapy typically damages dividing cells broadly (cytotoxic effect). Targeted therapies act on specific molecular abnormalities in cancer cells (for example, tyrosine kinase inhibitors). Immunotherapies boost or redirect the immune system to recognize and kill cancer cells. Treatment often combines approaches.
How do doctors determine the chemotherapy dose?
Dose decisions use body-surface-area calculations, organ function tests (kidney, liver), drug interactions, patient frailty, and increasingly pharmacogenomic data. Some drugs use fixed doses rather than BSA-based dosing.
Are there oral chemotherapy options?
Yes. Many newer agents and some traditional drugs are available in oral form, allowing home administration. Oral regimens still require monitoring for adherence and side effects.
What are the most common side effects, and can they be managed?
Common effects include nausea, fatigue, hair loss, mouth sores, neuropathy, and low blood counts. Improved supportive care - modern antiemetics, growth factors (G-CSF), and symptom management - can greatly reduce complications.
Does chemotherapy always aim to cure cancer?
Not always. Chemotherapy can be curative, used before surgery to shrink tumors (neoadjuvant), after surgery to reduce recurrence risk (adjuvant), or palliative to relieve symptoms and prolong life.

News about Cancer Chemotherapy

The 'brilliant invention' helping cancer patients in Shropshire - BBC [Visit Site | Read More]

Nivolumab/Chemo Yields Long-Term Survival in Advanced Gastric Cancers - CancerNetwork [Visit Site | Read More]

Proton beam therapy comes to Minecraft to help children prepare for cancer treatment at The Christie - The Christie [Visit Site | Read More]

Cancer waiting times: Latest updates and analysis - Cancer Research UK - Cancer News [Visit Site | Read More]