The study, “Association of thyroid, breast and renal cell cancer: a population-based study of the prevalence of second malignancies,” was published online ahead of print in December 2012. It appears in the Annals of Surgical Oncology.
The goal of the study was to explore the prevalence of a second malignancy in patients who were treated for thyroid cancer, breast cancer, or renal cell cancer. The researchers note that past data has shown a connection between thyroid cancer and preexisting malignancies.
To explore these connections, the researchers used the data system Explorys to identify and examine patient cohorts. Prevalence rates were determined for each cancer type. The rates of second malignancy were also obtained and compared for each type of cancer.
Female patients with thyroid cancer had a risk of subsequent breast cancer that was 0.67 compared to patients without thyroid cancer, and a twofold increase in renal cell cancer risk. Women with breast cancer had a twofold increase in thyroid cancer prevalence and a 1.5-fold increase in renal cell cancer prevalence.
Men with thyroid cancer had a 29-fold increase in breast cancer prevalence, and a 4.5-fold
increase in renal cell cancer prevalence. Men with breast cancer had a 19-fold increased prevalence of subsequent thyroid cancer, while the risk was threefold for men with renal cell cancer.
The study authors conclude that their results demonstrate numerous associations between thyroid cancer, breast cancer, and renal cell cancer, and that these associations exist in both men and women. They argue that these findings highlight the need for adequate patient follow-up and subsequent cancer screening following treatment for cancer.