Risk of second cancer related to treatment of first cancer

The aim of a multinational study series in collaboration with the U.S. National Cancer Institute is to evaluate the risk of second cancers related to a treatment of the first malignancy. Numerous studies of this project have been published since the 1990s.

The autumn 2005 papers concentrate on the risk of second cancer among survivors of testicular cancer and Hodgkin's lymphoma. They are based on information from 14 Cancer Registries from North America and Europe. In short, the life-long incidence of new cancer a typical testicular cancer patient who has survived 10 years is over 30% as compared with 25% among comparable men in the reference populations. Due to low incidence of cancers in younger ages, the relative excess risk is highest among young survivors of testicular cancer although the excess absolute risk is not (see the graph below).

For a 25-year-old woman who received typical mantle-field radiation therapy for her Hodgkin's lymphoma, the risk of developing breast cancer by age 55 years is 29%, remarkably higher than the respective risk of a 25-year-old woman in the general population (about 3%).   As a comparison, a 50-year-old woman who takes hormone replacement therapy for 10 years has a chance of about 8% of developing breast cancer over the next 30 years.

The principal investigator of this project at the Finnish Cancer Registry is Eero Pukkala, and professor Heikki Joensuu from Helsinki University Hospital coordinates the abstracting of treatment-related factors.