摘要New therapies and supportive care have converted several cancer types into chronic conditions.Yet,some tumors exhibit features reproducibly correlated with poor prognosis outcome(PPO-tumors).Bacteria in a tumor environment can inactivate chemotherapeutics and are a feature of PPO-tumors,although standard diagnostic tests for tumor infections do not exist.Optimism is high for nanotechnologic innovations but nanoparticulate chemotherapeutics based on enhanced permeability and retention in a human tumor environment have only shown limited treatment benefits.Moreover,treatment of infected tumors in animals with stimuli-responsive nanocarriers loaded with an antibiotic/chemotherapeutic combination has demonstrated limited benefits compared to treatment with combinations of carrier-free antibiotics and chemotherapeutics.Development of nanoparticulate chemotherapeutics with significant benefits in human clinical use is estimated to take several decades,which is too long for patients with PPO-tumors.Herein we hypothesize the following:1-all diagnosed PPO-tumors are infected with bacteria;2-all PPO-tumors in mice and humans exhibit enhanced permeability to chemotherapeutics;and 3-all diagnosed PPO-tumors must be treated from the onset with a combination of carrier-free antibiotics and chemotherapeutics.Each hypothesis was critically evaluated and judged plausible and clinically acceptable.Potential clinical treatment of PPO-tumors,presuming bacterial infection without diagnosis,with an approved antibiotic and chemotherapeutic free drug combination requires a paradigm change in treatment concept towards more lenient antibiotic use.However,many cancer patients already require antibiotics during chemotherapeutic treatment and combined carrier-free antibiotic/chemotherapeutic treatment may provide an immediate pathway to re-sensitize PPO-tumors to clinically used chemotherapeutics and alter the prognosis to a more favourable outcome.