Explore the fundamental approaches to cancer treatment: surgery, radiotherapy, and chemotherapy. Learn their mechanisms, goals (curative, palliative), and how t
WEEK 2 — Treatment Approaches in Oncology 1. Surgery The oldest form of cancer treatment. Goals: - Curative — remove entire tumor (early stage, localized) - Debulking — remove as much tumor as possible to help other treatments work - Palliative — relieve symptoms (e.g. obstruction) without curing - Preventive — remove pre-cancerous tissue (e.g. colectomy in FAP) Limitations: - Can't remove microscopic spread - Not useful for systemic cancers (leukemia, lymphoma) - Risk of seeding (spreading cancer during surgery) --- 2. Radiotherapy Uses ionizing radiation to damage cancer cell DNA → cell death. How it works: - Radiation → creates free radicals → breaks DNA strands - Cancer cells are more sensitive because they divide fast and have poor DNA repair Types: Type Detail --- --- External beam Radiation aimed from outside the body Brachytherapy Radioactive source placed inside/near tumor (e.g. prostate, cervix) Stereotactic Very precise high-dose radiation (e.g. Gamma Knife for brain) Fractionation — dose given in small daily fractions over weeks - Allows normal cells to repair between sessions - Cancer cells can't repair as efficiently Side effects: - Local — depends on site (e.g. mucositis, skin burns, hair loss at site) - Fatigue - Long term — fibrosis, secondary malignancies --- 3. Pharmacotherapy (Chemotherapy) Using drugs to kill or control cancer. This is the bulk of the unit so Week 2 is just an intro. How chemo works generally: - Targets rapidly dividing cells - Interferes with DNA, cell division, or metabolism Problem: Normal rapidly dividing cells also get hit - Bone marrow → myelosuppression (low WBC, RBC, platelets) - GI tract → nausea, vomiting, mucositis - Hair follicles → alopecia Goals of chemo: Goal Meaning --- --- Curative Aim to cure (e.g. leukemia, testicular cancer) Adjuvant After surgery — kill residual cells Neoadjuvant Before surgery — shrink tumor first Palliative Control symptoms, prolong life Routes: IV most common, also oral, intrathecal, intraperitoneal --- How the 3 Work Together Most cancers need combination treatment: Surgery removes bulk → Radiation kills local residual → Chemo kills systemic spread Example: Breast cancer - Surgery (lumpectomy) + Radiotherapy (local control) + Chemo/Hormonal therapy (systemic) --- Quick Recall Treatment Mechanism Best for --- --- --- Surgery Physical removal Solid, localized tumors Radiotherapy DNA damage via free radicals Local tumors, post-surgery Chemotherapy Target dividing cells Systemic, adjuvant, palliative Fractionation Split radiation doses Spare normal tissue Adjuvant chemo After surgery Kill microscopic residual disease Neoadjuvant chemo Before surgery Shrink tumor, make operable