Cancer treatment has witnessed remarkable progress in recent years, with significant advancements in systemic therapies. These therapies, including targeted therapies and immunotherapy, have revolutionised the landscape of cancer care, offering new hope and improved outcomes for patients.
What is chemotherapy?
Chemotherapy essentially is treatment that is a form of systemic therapy and involves the use of chemical drugs to treat cancer. These drugs are primarily available as injectable formulations, although some can be taken orally. In certain cases, chemotherapy may be administered directly into specific body areas such as the cerebrospinal fluid, pleura, or abdomen (known as intraperitoneal chemotherapy).
The primary goal of chemotherapy is to shrink tumours by halting the proliferation of cancer cells and causing their death. However, because chemotherapy drugs target rapidly dividing cells, they can also affect healthy cells in the body that naturally divide rapidly. This leads to common side effects such as low levels of red blood cells, white blood cells, and platelets (resulting in anaemia, increased infection risk, and bleeding issues), as well as effects on the skin (including nail changes) and hair loss. The gastrointestinal tract may also be affected, resulting in reduced appetite, vomiting, diarrhoea, and fatigue. Additionally, chemotherapy drugs can have side effects on various organ systems such as the lungs, heart, liver, kidneys, and nervous system. The specific side effects experienced can vary depending on factors like the pharmacokinetics of the drug and the targeted organs.
Fortunately, there are many effective drugs available to help manage and alleviate the side effects of chemotherapy, making it easier for patients to tolerate the treatment. These supportive medications play a crucial role in improving the overall experience and quality of life during chemotherapy.
What are the recent advances in systemic therapy?
Significant progress has been made in cancer care over the past two decades, encompassing advancements in surgery and radiation therapy. These refinements have greatly enhanced the ability to control cancer locally and have led to significant reductions in associated morbidity and mortality. In addition, the introduction of targeted therapies and immunotherapy has brought about novel approaches to systemic therapy, further expanding treatment options for cancer patients.
How have targeted therapies changed the landscape of cancer treatment?
Targeted therapies encompass both oral and intravenous treatments that hinder the growth of tumour cells. They achieve this by interacting with cell surface receptors (monoclonal antibodies) that spur cell multiplication or by binding with target enzymes inside the cell (tyrosine kinase inhibitors). This action inhibits downstream signalling pathways that drive tumour cell division. Targeted therapies have been transformative in the treatment of numerous cancers over the past two decades. Some diseases, such as chronic myeloid leukaemia and acute promyelocytic leukaemia, have achieved outcomes comparable to cure with their use. They have also significantly improved survival rates in lymphomas, breast cancer, ovarian cancer, lung cancer, renal cell carcinoma, and hepatocellular carcinoma. As targeted therapies attach to specific molecules on or within tumour cells, their side effects are generally less widespread compared to chemotherapy. However, they do have class-specific and agent-specific side effects. Targeted therapies are generally better tolerated and more convenient to administer than chemotherapy.
What is immunotherapy?
This is the recent most exciting addition to the armamentarium of systemic therapies. They act by aiding the immune system to mount a response against the tumour cell. They have been revolutionary in altering management and outcomes of a few cancers such as lung cancer, renal cell cancer, malignant melanoma. They have also shown benefit in multiple other solid tumours such as colon cancer, genitourinary cancers, head and neck cancers and other tumors that carry a high tumour mutation burden. Their side effect profiles differ from that of chemotherapy and targeted therapies. They can cause autoimmune side effects on literally any system of the body, and hence their monitoring and management are specific to this class of drug.
Other newer, but highly tumour specific therapies include BiTE (Bispecific T-cell engager) cell, CAR-T (chimeric antigen receptor T-cell) cell therapies for lymphomas and leukaemias and therapeutic vaccines such as Sipuleucel-T cell therapy for carcinoma prostate, which are also forms of immunotherapy.
So, can all these newer treatments benefit all cancers?
Immunotherapy represents a recent and remarkable advancement in systemic therapies. Its mechanism involves supporting the immune system to mount a response against tumour cells. Immunotherapy has revolutionised the management and outcomes of certain cancers, including lung cancer, renal cell cancer, and malignant melanoma. It has also shown benefits in various other solid tumours, such as colon cancer, genitourinary cancers, head and neck cancers, and tumours with a high tumour mutation burden. Unlike chemotherapy and targeted therapies, immunotherapy has distinct side effect profiles. It can lead to autoimmune side effects in any system of the body, necessitating specific monitoring and management approaches.
Other newer tumour-specific therapies include BiTE (Bispecific T-cell engager) cell therapy, CAR-T (chimeric antigen receptor T-cell) cell therapy for lymphomas and leukaemias, and therapeutic vaccines like Sipuleucel-T for prostate carcinoma. These therapies also fall under the category of immunotherapy.
Conclusion
Recent advancements in cancer treatment, including chemotherapy, targeted therapies, and immunotherapy, have revolutionised care, offering improved outcomes and hope for patients. Chemotherapy uses drugs to shrink tumours but can have side effects on healthy cells. Targeted therapies and immunotherapy have specific mechanisms to hinder tumour growth and support the immune system, with fewer side effects compared to chemotherapy. Ongoing research promises a brighter future in cancer treatment.
If you are looking for expert advice for cancer treatment, you can consult with Dr. Suparna Rao, Consultant - Medical Oncology, P. D. Hinduja Hospital & Medical Research Centre, Mahim, Mumbai.
To book an appointment, please contact the hospital at the following phone numbers: 022 6766 8181 or 022 4510 8181.
*Information source: Bombay Times
