Abstract: A diagnostic technique for matching anti-cancer peptide drugs to the molecular profiles of individual cancer tumors, and a method using the technique for a patient-specific treatment of tumors in mammals. This strategy matches anti-cancer peptide drugs to the molecular profiles of individual tumors, and includes the development of two banks, both of which use the same targeting peptides. Targeting peptides are identified using biopsies or other tissue materials from multiple cancer patients and placed into two banks. For a bank of probes, targeting peptides are linked to a label such as a fluorescent or a radioisotope. For a bank of drugs, targeting peptides are linked to a cytotoxic peptide to form a “targeting peptide drug”. Peptide probes are used to establish molecular profiles of individual tumors. Based on these molecular profiles, a patient-specific combination of targeting drugs from the bank of peptide drugs is prepared and the patient is treated.