Prevalence of multiple malignancies in the Netherlands in 2007.

As the number of cancer survivors increases in the Netherlands, there is a concomitant increase in patients with multiple malignancies (MMs), the prevalence of which needs to be assessed to estimate care needs. This study analyzed incidence data on all malignant cancers diagnosed between 1989 and 2006 retrieved from the population-based Netherlands Cancer Registry. The point prevalence of MMs was determined on January 1, 2007. Of all cancer survivors in 2007, 30,064 (7% of the total) were patients with MMs. Their median age was 74 (interquartile range 71-76) years. Ninety two percent (i.e., 27,660) of these patients had two cancer diagnoses. The most common subsequent cancers being squamous cell skin cancer (5,468), colorectal cancer (4,634), and breast cancer (3,959). High frequency of combinations included: (i) female breast and genital cancers (any order), (ii) urinary tract and prostate cancers (any order), (iii) Hodgkin's lymphoma and subsequent female breast cancer and (iv) non-Hodgkin's lymphoma and subsequent squamous cell skin cancer. As the number of cancer survivors continues to increase and their survival improves, MMs are becoming more important in the field of cancer surveillance.