Abstract 5767: Multiple primary cancer from a retrospective population-based cancer registry, 1991 through 2015

Abstract

Background Multiple primary cancer refers to the synchronous or metachronous appearances in the same individual. The accurate approach, which distinguishes between multiple primary cancer and metastasis, is important to make an appropriate management. This study aims to systematically classify the synchronous and metachronous multiple primary cancers, and to identify multiple primary cancer from cancer metastasis. Methods Cancer registry was compiled at the Faculty of Medicine Siriraj Hospital, Mahidol University based on guidelines from the Surveillance Epidemiology and End Results (SEER) project. Data was validated through clinical records, coded, and verified for multiple primary cancer according to International Classification of Diseases for Oncology 3rdEdition (ICD-O-3). The cancer registry for the year 1991-2015 was queried for numbers of the multiple primary cancer. Results A total of 1,913 patients presented multiple primary cancer, accounting for 1.48% of all patients (129,216). Median age at diagnosis of the first cancer was 60. The most multiple primary cancer in female is synchronous breast cancers, diagnosed two or more histologically distinct cancer within two months. In male, the most combination is prostate, urinary tract, and gastrointestinal cancer. In addition to understanding of the connections between primary and subsequent cancer, we plan to perform panel sequencing in each primary site of multiple gastrointestinal primary cancer to access for the causal driver mutation. Conclusion Cancer registry is a valuable approach to punctually identify and record multiple primary cancer. Further study in genetic profiles of each primary cancer may improve our understanding of multiple primary cancer for enhancing cancer management. Citation Format: Pariyada Tanjak, Benjarat Thiengtrong, Kanokporn Thamapala, Tippawan Gerdsuriwong, Cholticha Songjang, Aem-on Rattanakumnerd, Onchira Acharayothin, Supatee Karakate, Nongnard Thamnongdee, Suwanit Therasakvichya, Somsri Laiteerapong, Vitoon Chinswangwatanakul. Multiple primary cancer from a retrospective population-based cancer registry, 1991 through 2015 [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5767.