Tumor Growth

Tumor growth refers to the progressive increase in size and cellularity of a neoplasm due to uncontrolled proliferation of abnormal cells. It is driven by genetic mutations, altered signaling pathways, and evasion of growth-suppressing mechanisms.

• Gompertzian growth model: Tumors grow rapidly in early stages, then slow as they outgrow their blood supply
• Doubling time: Varies by tumor type and biological behavior
• Tumor burden: Total number or volume of cancer cells present

• Sustained proliferative signaling (e.g., EGFR, KRAS, BRAF)
• Evading growth suppressors (e.g., p53, RB)
• Resisting cell death (e.g., BCL2 overexpression)
• Enabling replicative immortality (e.g., telomerase activation)
• Inducing angiogenesis
• Activating invasion and metastasis

• PI3K/AKT/mTOR
• RAS/RAF/MEK/ERK (MAPK pathway)
• EGFR signaling
• MYC oncogene
• Wnt/β-catenin

• Stromal cells, immune cells, and blood vessels interact with tumor cells to promote:
  • Growth
  • Immune evasion
  • Angiogenesis
  • Therapy resistance

• Radiological assessment: MRI, CT, PET
• Response criteria: RECIST 1.1 (Response Evaluation Criteria in Solid Tumors)
• Biomarkers: Ki-67 (proliferation index), LDH, PSA, CA-125, etc.

• Cytotoxic agents: Kill proliferating cells (e.g., alkylating agents, antimetabolites)
• Targeted therapies: Block growth-promoting pathways (e.g., EGFR, BRAF inhibitors)
• Immunotherapies: Stimulate immune system to suppress or eliminate tumors
• Radiotherapy: Damages DNA in rapidly dividing tumor cells

• Proliferation Index (Ki-67)
• EGFR Pathway
• Angiogenesis
• Tumor Microenvironment
• Targeted Therapy
• RECIST Criteria