Introduction:
In Poland, data on neoplasms is collected in the National Cancer Registry (NCR) and the National Health Fund (NHF). The completeness of registration and the consistency of data in both systems are the basis for planning and prevention in health care. The aim of this paper is to analyse the incidence of breast cancer and colorectal cancer in the Silesian province based on data from the available cancer registry sources (NCR and NHF), differing in the manner and scope of data collection.

Material and methods:
Data on the incidence of breast cancer and colorectal cancer in the cities of Silesian province was analysed. The data concerned the year 2012 and was collected in the NCR and NHF. The NHF database included a total of 3.632.486 records, from which cases of breast and colorectal cancers for the year 2012 were distinguished. These data were compared with the morbidity for breast cancer and colorectal cancer shown in the NCR.

Results:
The analysis showed significant differences between the absolute number of neoplasm cases registered in the NHF and NCR. The NHF database included a greater number of cases, both for breast cancer and colorectal cancer. In the male population, in 1/5 of the analysed cities, the number of colorectal cancer cases registered by the NCR exceeded the values recorded by the NHF.

Conclusions:
The differences in data concerning breast cancer and colorectal cancer between the NCR and NHF may lead to inadequate planning of oncological medical services.