Cancer Tissue Classification, Associated Therapeutic Implications and PDT as an Alternative

Carcinogenesis occurs via mutation of critical genes conferring enhanced survival and protection to the ensuing tissue. Current therapies in use garner success due to their specificity for certain intracellular targets. This particularity, whist beneficial in identifying tumorigenic from normal tissue states, is limited by the variations in geno/phenotypic profiles displayed between tumor tissue types. As such, tissue-specific therapeutic combinations and adjuvants are often required for adequate effect, but present symptomatic complications and occasionally generate secondary carcinogenesis displaying multi-drug resistance (MDR). An accumulation of research over the recent years has suggested that photodynamic therapy (PDT) with macrocycle photosensitizers are a promising alternative. Its administration method and toxicity mechanism present attractive features for potentially overcoming MDR cancers of multiple tissue origins with limited symptomatic onsets. Herein, we highlight these potentials as referenced against existing therapeutics and consider the impact of macrocycle-PDT for broad spectrum application regardless of tumorigenic resistance profiles.