Clinicopathological Features of Patients Diagnosed with Both Primary Thyroid Cancer and Primary Renal Cell Cancer and Its Comparison with Patients with Thyroid Cancer or Renal Cell Cancer Alone

ABSTRACT

Background and Objectives@#Thyroid cancer (TC) and renal cell carcinoma (RCC) display more frequent co-occurrence than would be expected by chance. We investigated clinicopathological features of patients with both primary TC and primary RCC (TC/RCC) group to facilitate a greater understanding of the relationship between two cancers. @*Materials and Methods@#A total of 53 patients who diagnosed with TC/RCC were enrolled. 13,663 TC-alone and 3279 RCC-alone patients who had undergone surgery at Samsung Medical Center between 1994 and 2014 were included as control groups. The clinicopathological characteristics of these patients were retrospectively reviewed. @*Results@#The median age at the time of TC or RCC diagnosis was 54 years in TC/RCC group and the RCC-alone group, while the patients in TC-alone group were significantly younger (47 years). The TC/RCC group showed a nearly equal sex prevalence (49% male), significantly different than the results of the TC-alone group (80% female) and RCC-alone group (71% male). A higher grade of pathologic stage (56.6% in stage 3) and greater number of patients with multifocality of thyroid tumors (45 vs. 32%), and more family history of cancer (32 vs. 0.4%) were revealed in TC/RCC group than in TC-alone group. In addition, 15.1% of patients in TC/RCC group presented with additional primary cancers such as prostate, colon, stomach, breast, and lung cancers. Conclusion: Patients in the TC/RCC group have a high rate of cancer family history, multifocality of thyroid tumors, and additional cancers. To understand this unique subset group, additional studies for environmental and genetic factors would be helpful for earlier diagnosis of combined cancers.