Cancer Treatment Modalities: Surgery, Radiation, Systemic Therapy & Emerging Approaches

Cancer comprises >200 distinct diseases, each requiring tailored treatment. While no universal cure exists, many cancers are curable or controllable with modern multimodal therapy. Treatment selection depends on cancer type, stage, molecular profile, patient health, and preferences.

Established Curative/Control Modalities

1. Surgery

• Primary treatment for most solid tumors. Goal: complete resection (R0) with negative margins.
• Techniques: Open, laparoscopic, robotic, endoscopic, Mohs (skin).
• Lymph node dissection/sentinel node biopsy for staging.
• Reconstructive surgery restores form/function.

2. Radiation Therapy

• High-energy X-rays/particles damage cancer cell DNA.
• External Beam (EBRT): 3D-CRT, IMRT, VMAT, SBRT/SRS (high-dose, few fractions).
• Brachytherapy: Internal sealed sources (prostate, cervix, breast).
• Proton Therapy: Bragg peak spares distal tissues; pediatric, base-of-skull, re-irradiation.
• Used definitive, adjuvant, neoadjuvant, palliative.

3. Systemic Therapy

Chemotherapy

Cytotoxic drugs targeting rapidly dividing cells. Classes: alkylators, antimetabolites, anthracyclines, taxanes, platinum, vinca alkaloids, topoisomerase inhibitors. Adjuvant, neoadjuvant, palliative.

Targeted Therapy

Drugs against specific molecular drivers:

• HER2: trastuzumab, pertuzumab, T-DM1, T-DXd, tucatinib
• EGFR: osimertinib, erlotinib (NSCLC); cetuximab (CRC, HNSCC)
• BCR-ABL: imatinib, dasatinib (CML)
• BRAF/MEK: dabrafenib+trametinib (melanoma)
• CDK4/6: palbociclib, ribociclib, abemaciclib (HR+ breast)
• PARP: olaparib (BRCA-mutated ovarian, breast, prostate, pancreatic)
• BTK: ibrutinib (CLL, MCL)

Hormonal/Endocrine Therapy

Breast (ER+): SERMs (tamoxifen), AIs (letrozole), SERDs (fulvestrant), ESR1-targeted (elacestrant). Prostate: ADT (LHRH agonists/antagonists), AR inhibitors (enzalutamide, darolutamide).

Immunotherapy

• Checkpoint Inhibitors (PD-1/PD-L1, CTLA-4): Pembrolizumab, nivolumab, atezolizumab, ipilimumab. Approved in melanoma, NSCLC, RCC, urothelial, HCC, HNSCC, MSI-H/dMMR tumors, TNBC, cervical, esophageal, gastric.
• CAR-T Cell Therapy: Autologous T cells engineered to target CD19 (B-cell malignancies), BCMA (myeloma).
• Bispecific Antibodies: Teclistamab (BCMA×CD3), mosunetuzumab (CD20×CD3).
• Cancer Vaccines: Sipuleucel-T (prostate); personalized neoantigen vaccines in trials.

Emerging & Investigational Approaches

• Antibody-Drug Conjugates (ADCs): Beyond HER2—TROP2 (sacituzumab govitecan), NECTIN4 (enfortumab vedotin), FRα (mirvetuximab), B7-H3, HER3. Broadly applicable.
• Radiopharmaceuticals: Lu-177-PSMA (prostate), Lu-177-DOTATATE (NETs), Ac-225-PSMA (alpha).
• Cell Therapy: TCR-T, TIL therapy, NK cells, allogeneic "off-the-shelf" products.
• Gene Therapy/Editing: CRISPR for T-cell engineering, oncolytic viruses (T-VEC approved melanoma).
• Microbiome Modulation: FMT, live biotherapeutics to enhance immunotherapy response.
• AI/ML-Guided Therapy: Radiomics, pathomics, liquid biopsy for real-time adaptation.

Multidisciplinary Care

Tumor boards (surgery, medical oncology, radiation oncology, pathology, radiology, genetics, palliative care, nursing, navigation) ensure comprehensive, evidence-based, patient-centered plans.

Key Principle

Treatment is increasingly personalized—driven by biomarkers (genomic, proteomic, imaging), not just histology. Clinical trials offer access to tomorrow's standards today. Discuss all options with your oncology team.