What are multiple primary malignancies?

Over the past 30 years, the incidence of cancer in Poland has more than doubled. Advances in technology, early diagnosis and improved treatment make more and more malignancies curable. An increase in the survival of cancer patients has also been observed. An increased rate of survival leads to the development of subsequent malignancies. Their cause is yet unclear however, chemotherapy as well as genetic and environmental factors may be involved in the process. The key prognostic factors for patients who were once diagnosed with cancer are: type of cancer, its stage and available treatment options. The aim of this work is to introduce the issue of multiple primary malignancies, with particular emphasis on their epidemiology. From the perspective of the whole population, the occurrence of multiple malignancies is quite rare. Triple or quadruple malignancies are even less common. Multiple malignancies may develop at any age, although, as it is shown in this paper, the type of cancer, its stage and location vary depending on the age at which the first and later subsequent cancers have presented. The most frequently found subsequent cancers are: colon cancer, lung cancer, cancers of the genital system and breast cancer. Based on statistical analysis and current literature, we discuss the risk of developing a second malignancy depending on the type of cancer that was diagnosed first.