Background: Cancer burden in the Czech population ranks among the highest worldwide, which introduces a strong need for a prospective modelling of cancer incidence and prevalence rates. Moreover, a prediction of number of cancer patients requiring active anti-tumor therapy is also an important issue. This paper presents the stage- specific predictions of cancer incidence and prevalence, and the stage- and region- specific patients requiring active anti-tumor therapy for the most common cancer diagnoses in the Czech Republic for years 2015 and 2020. The stage- specific estimates are also presented with regard to the treatment phase as newly diagnosed patients, patients treated for non-terminal recurrence, and patients treated for terminal recurrence. Patients and Methods: Data of the Czech National Cancer Registry from 1977 to 2011 has been used for the analysis, omitting the records of patients diagnosed as death certificate only or at autopsy. In total, 1,777,775 incidences have been considered for the estimation using a statistical model utilizing solely the population-based cancer registry data. All estimates have been calculated with respect to the changing demographic structure of the Czech population and the clinical stage at diagnosis. Results: Considering year 2011 as the baseline, we predict 89%, 15%, 31% and 32% increase in prostate, colorectal, female breast and lung cancer incidence, respectively, in 2020 resulting in 13,153, 9,368, 8,695, and 8,604 newly diagnosed cancer patients in that year, respectively. Regarding cancer prevalence in 2020, the estimated increase is 140%, 40%, 51%, and 17% for prostate, colorectal, female breast and lung cancer, respectively, meaning that more than 100,000 prevalent female breast cancer patients as well as more than 100,000 prevalent prostate cancer patients are expected in the Czech Republic. The estimated numbers of patients requiring active anti-tumor therapy for prostate, colorectal, female breast and lung cancer in the Czech Republic in 2020 are 23,652, 14,006, 14,759 and 8,272; respectively. Conclusions: The analysis documents a serious increase in cancer incidence and prevalence in the Czech Republic in years 2015 and 2020 when compared to the situation in 2011. Regarding the estimated numbers of patients requiring active anti-tumor therapy, the model confirms a continuous increase that must be accounted for in the future planning of health care in the Czech Republic.