Peptide-based
cancer vaccines are able to induce strong immune responses, but their clinical results are unsatisfactory. To determine clinically correlated
peptides, we analyzed survival data from
urological cancer patients treated by personalized
peptide vaccination (PPV), in which different multiple
peptides were used for individual patients based on
human leukocyte antigen (HLA) type and pre-existing immunity. Survival data were obtained from a database of 265
urological cancer patients treated in 5 clinical PPV trials comprising 154 patients with
castration-resistant
prostate cancer (CRPC) and 111 patients with advanced urothelial
cancer (UC). Expression of
tumor-associated
antigens (TAA) was evaluated in 10
prostate cancer tissues, 4 metastatic lymph nodes from
prostate cancer, and 10 UC tissues using immunohistochemical staining. Clinical efficacy of individual
peptides for overall survival was evaluated by the Cox proportional hazards regression model. All TAA coding candidate
peptides used in PPV treatment were expressed in
tumor cells from
prostate cancer and UC samples except for p56Lck in both, and
prostate-specific antigen (PSA),
prostatic acid phosphatase (PAP) and prostate-specific membrane
antigen (PSMA) in the UC samples. Patients with the following
peptides had a significantly longer survival than patients without the
peptides (hazard ratio <1.0, 95% confidence intervals <1.0 and P < .05): SART3-109, PTHrP-102, HNPRL-140, SART3-302 and Lck-90 in CRPC patients, and EGF-R-800, Lck-486, PSMA-624, CypB-129 and SART3-734 in advanced UC patients, respectively. Correlated
peptides selected using both survival data and pre-existing immunity for PPV treatment may enhance the clinical benefits for
urological cancer patients.