Peptide-based cancer therapies show promise with multifunctional peptides for diagnosis, targeting, and treatment (theranostics). AI and machine learning aid in peptide sequence design, and integration with other therapies enhances treatment. Clinical trials highlight peptide-drug conjugates and imaging agents. Peptides offer high specificity, reduced toxicity, and adaptable characteristics. Over 30 peptide drugs approved globally. Peptide attributes include compact structure and strong selectivity. Examples: goserelin for breast and prostate cancer, octreotide for neuroendocrine tumors. Market report highlights include a $18 billion opportunity, 30+ approved drugs, and 230+ drugs in clinical trials. Peptides transform diagnostics with radiolabeled peptides for PET imaging. Therapeutic approaches include targeting cancer cells, delivering cytotoxic agents, and peptide vaccines. Innovations in peptide engineering and delivery mechanisms expand their scope. Personalized medicine and ongoing research position peptides as key in future cancer care.