Aims We carried out a large scale study to identify the risk factors for double primary malignancy (DPM) development in gastric cancer patients and to evaluate the clinical implications for these patients. Methods A total of 2593 patients who underwent gastrectomy for primary gastric cancer from January 2005 to November 2010 were reviewed with regard to DPM. We compared the clinicopathological characteristics, risk factors for developing DPM, and prognosis between the DPM(+) group and the DPM(-) group. Results Of the 2593 patients, 152 (5.9%) were diagnosed with DPM. The most common accompanying malignancies were colorectal, lung and thyroid. Multivariate analysis indicated that age (p = 0.016) and MSI status (p = 0.002) were associated with a higher frequency of DPM. 30.3% of patients were diagnosed with DPM within 1 year around perioperative period and 53.3% of patients had DPM detected during 5 years of post-operative follow up periods. Although there was no significant difference in overall survival between the DPM(+) and DPM(-) group, DPM(+) patients had a worse prognosis than DPM(-) patients in stage I gastric cancer. Conclusions Gastric cancer patients over the age of 60 or with a MSI-high status had an increased risk for developing DPM. Further, in stage I gastric cancer, the presence of DPM was associated with a worse prognosis. Therefore, careful pre- and postoperative surveillance is especially important in these patients.
Bibliographical noteFunding Information:
This research was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology ( 2011-0011301 ).
This research was supported by a faculty research grant from Yonsei University College of Medicine for 2011 ( 6-2011-0084 ).
This research was supported by eVelos System , which is a web-based clinical study management system (NCC Grant: NCC 1210120-1 ) and a grant from the Korea Healthcare Technology R&D Project, Ministry of Health and Welfare, Republic of Korea ( A102065 ).
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