Prevalence and treatment outcomes of second primary malignancies in Saudi patients with differentiated thyroid cancers

Abstract

Objectives:To evaluate the clinicopathologic features, and explore the treatment outcomes of synchronous, or metachronous second primary malignancies (SPM) in conjunction with differentiated thyroid cancers (DTC).Methods:This retrospective study was conducted on 823 DTC patients treated between 2000 and 2012 at 2 tertiary care hospitals (King Fahad Medical City and King Khalid University Hospital) in Riyadh, Kingdom of Saudi Arabia. Forty-one (5%) DTC patients were found to have SPM (61% metachronous and 39% synchronous). These patients with SPM were studied for clinicopathological features and treatment outcomes.Results:The patients with DTC and SPM were older (median age: 54.3 years) than those without SPM (median age: 43.2 years); p=0.04. The frequency of SPM was breast (51.2%), colon (12.2%), kidney (7.3%), astrocytoma (7.3%), parotid (7.3%), rectum (4.9%), lymphoma (4.9%), nasopharynx (2.4%), and stomach (2.4%). Median follow-up was 8.05 years. Ten-year disease free survival, and overall survival (OS) rates were lower in DTC patients with SPM (56.1% for 10-year survival, and 71.7% for OS) than without SPM (95.5% for 10-year survival, and 97.8% for OS); p=0.0001. Metachronous SPM had better 10-year disease free survival rates (60.2%) than synchronous SPM (45%).Conclusion:The co-occurrence of SPM with DTC affects long-term disease free survival and OS rates.

Second Primary Malignancies in Patients with Differentiated Thyroid Cancer after Radionuclide Therapy: A Retrospective Single-Centre Study

“…The present investigation demonstrates that 131 I cumulative activity dose is not associated with SPM development in DTC patients after RAI therapy, even considering different administered activity categories. This finding is in agreement with numerous prior studies [5,[11][12][13][14]19,20,[27][28][29][30]. However, in the study by Hong et al [27] total cumulative dose over 200 mCi was significantly associated with SPM development.…”

“…Therefore, the association between RAI and the risk of SPM development in DTC patients is still controversial. It is certainly very important that every patient must be contextualized and deserves a personal medical evaluation based on their genetic and clinical background [5,[7][8][9][10][11][12][13][14][15][16][17][18][19][20]. With regard to women, in the studied population, only one out of the eight female patients developing breast cancer was of childbearing age, while the other seven were in postmenopausal age at the time of RAI, further supporting data that excludes a potential relationship between RAI and breast cancer development.…”

“…Discordant data regarding the development of SPM in patients treated with RAI have been reported [7][8][9][10][11][12][13][14][15][16][17][18][19][20]27]. Undeniably, the body of evidence provided by literature on this topic shows a wide heterogeneity in methods and results [7][8][9][10][11][12][13][14][15][16][17][18][19][20]27]. To date, the risk of developing SPM after an RAI cannot be excluded a priori, but it is expected to be low [10][11][12]17,18,20].…”

“…Undeniably, the body of evidence provided by literature on this topic shows a wide heterogeneity in methods and results [7][8][9][10][11][12][13][14][15][16][17][18][19][20]27]. To date, the risk of developing SPM after an RAI cannot be excluded a priori, but it is expected to be low [10][11][12]17,18,20].…”

“…Second primary malignancies (SPM), described as any primary, not synchronous, malignancy arising in a different anatomical district with confirmed histological diagnosis, is reported in patients with DTC [5]. Actually, different incidences of SPM have been previously reported, ranging from 0.5% to 22% [7][8][9][10][11][12][13][14][15][16][17][18][19][20]. Moreover, several factors can influence the incidence of SPM in patients with DTC.…”