Tumour Targeting Strategies 1

What are the four major types of cancer treatment?

1. Surgery

2. Radiotherapy

3. Systemic chemotherapy

4. Targeted therapy.

What is curative surgery?

"Curative surgery removes the cancerous tumor or growth from the body, typically used when the cancer is localized to a specific area."

What is preventive surgery?

"Preventive surgery removes tissue that does not contain cancerous cells but could develop into a malignant tumor, such as polyps in the colon."

What is debulking surgery?

"Debulking surgery removes a portion of a cancerous tumor when removing the entire tumor could cause damage to an organ or the body."

What is palliative surgery?

"Palliative surgery is used to treat advanced-stage cancer to relieve discomfort or correct other problems, but it does not cure the cancer."

What is external beam radiotherapy?

"External beam radiotherapy uses a linear accelerator to deliver ionizing radiation to a targeted tumor area, causing irreparable DNA damage and cancer cell death."

What is proton beam radiotherapy?

"Proton beam radiotherapy uses protons, which can be more accurately targeted to spare healthy tissue while delivering radiation to the tumor."

What is internal radiotherapy?

"Internal radiotherapy places a radiation source inside the body, either as a solid (brachytherapy) or liquid (systemic therapy), to target the tumor."

What is systemic radiotherapy?

"Systemic radiotherapy involves administering a liquid radioactive substance (e.g., radioiodine for thyroid cancer) that is absorbed by the target tissue."

What is brachytherapy?

"Brachytherapy involves placing a radiation source directly into or near the tumor (e.g., in the lungs or bronchi) to minimize damage to surrounding tissues."

What are alkylating agents, and how do they work?

"Alkylating agents act directly on DNA, causing cross-linking, abnormal base pairing, or DNA strand breaks, and are used to treat slow-growing cancers."

What are antitumor antibiotics, and what is their mechanism of action?

"Antitumor antibiotics bind to DNA, prevent RNA synthesis, and include drugs like doxorubicin, mitoxantrone, and bleomycin."

What are vinca alkaloids, and how do they work?

"Vinca alkaloids interfere with cell division by targeting microtubules, preventing mitosis and causing cells to become stuck in metaphase."

What are antimetabolites, and what is their mechanism of action?

"Antimetabolites disrupt nucleic acid synthesis by interfering with the production of nucleotides or substituting for natural metabolites."

What is the molecular basis of targeted therapies?

"Targeted therapies exploit specific molecular abnormalities in cancer cells, such as overexpressed or mutated genes, to selectively kill cancer cells."

What is oncogene addiction?

"Oncogene addiction refers to the phenomenon where cancer cells become highly dependent on a single oncogene for their survival and proliferation, making it a therapeutic target."

What is the Philadelphia chromosome, and why is it significant in CML?

A reciprocal translocation between chromosomes 9 and 22, creating the BCR-ABL fusion protein, which drives chronic myeloid leukemia (CML)."

What is the role of biomarkers in targeted therapy?

"Biomarkers help identify patients most likely to respond to specific targeted therapies by indicating the presence of specific molecular targets in their tumors."

What is the mechanism of action of imatinib in CML?

"Imatinib inhibits the BCR-ABL tyrosine kinase, which is the driver oncogene in CML, leading to the selective killing of cancer cells."

What are the hallmarks of cancer in precision medicine?

• Sustaining proliferative signaling

• Evading growth suppressors

• Avoiding immune destruction

• Enabling replicative immortality

• Tumor-promoting inflammation

• Activating invasion & metastasis

• (Angiogenesis) Inducing or accessing vasculature

• Genome instability & mutation

• Resisting cell death

• Deregulating cellular metabolism

What is the goal of targeted therapy in cancer treatment?

"The goal of targeted therapy is to selectively kill cancer cells by exploiting their dependence on specific oncogenes or molecular pathways, ideally leading to tumor shrinkage."

What is the difference between chemotherapy and targeted therapy?

"Chemotherapy affects all rapidly dividing cells, including normal cells, while targeted therapy selectively targets cancer cells based on specific molecular abnormalities."

What is the role of topoisomerase inhibitors in cancer treatment?

"Topoisomerase inhibitors prevent DNA unwinding by blocking topoisomerase enzymes, leading to DNA strand breaks and cell death."

What is the mechanism of action of doxorubicin?

"Doxorubicin intercalates into DNA, disrupts topoisomerase enzymes, generates free radicals, and interacts with cell membranes, leading to DNA damage and cell death."

What is the significance of the BCR-ABL fusion protein in CML?

"The BCR-ABL fusion protein, resulting from the Philadelphia chromosome, is a constitutively active tyrosine kinase that drives the proliferation of hematopoietic stem cells in CML."