Presented is a method of prognosing a patient's response to a cancer therapy wherein prior to the therapy contacting a sample of cells from the patient's tissue or organ being treated for the cancer with a solution of TCPP to permit binding of the TCPP to components of the abnormal dysplastic or carcinomic cells, if any are present; detecting TCPP fluorescence in the sample, the presence of TCPP fluorescence being indicative that the sample contains dysplastic or carcinomic cells; at intervals during the therapy and subsequent to the therapy performing steps a-c on another sample of cells from the patient's tissue or organ being treated for the cancer; and determining if the percentage of abnormal pre-cancerous cells in the samples tested during and subsequent to the therapy are reduced as compared with the sample tested prior to the therapy, the reduction being prognostic of the patients response to the cancer therapy.