Behaviour and epidemiology of differentiated thyroid cancer among filipinos in and outside the Philippines: Comparison between Qatar, Canada and Philippines.

Background: No study assessed the behaviour/epidemiology of differentiated thyroid cancer (DTC) among Filipinos in the Middle East/north Africa; or compared such behaviour with Filipino DTC patients in and outside the Philippines.

Materials And Methods: Retrospective review of all adult Filipinos with DTC diagnosed between 2015 and 2020 at our institution [papillary TC (PTC, n = 110); follicular TC (FTC, n = 4)]. Chi-square or -test compared the frequency, demography, history, ultrasound, laboratory and histopathology of PTC vs FTC; and compared the epidemiology of DTC among Filipinos in Qatar vs Canada (1 study) vs the Philippines (3 studies).

Results: DTC frequency was ≈43.84 cases/100,000 Filipinos in Qatar. Males had more aggressive disease in terms of lymphovascular invasion, number of nodules, stage IV disease and metastases. PTC and FTC were similar, but more PTC patients presented with solid tumors and higher number of involved lymph nodes. DTC behaviour among Filipinos in Qatar vs Canada was fairly homogenous. Conversely, DTC among Filipinos in Qatar vs Philippines exhibited many dissimilarities: Qatar had significantly younger patients, less hyperthyroid/thyrotoxicity symptoms and neck swelling at presentation, fewer solid nodules, micro-calcifications, and multi-nodular disease; smaller tumors; more stage I and less stage IV disease; and no distant metastasis ( 0.01 to < 0.0001).

Conclusions: DTC epidemiology among Filipinos in Qatar and Canada was fairly homogenous. Conversely, DTC in Qatar vs the Philippines was dissimilar. DTC among Filipinos in Qatar has presentations that could be misinterpreted as non-suspicious. This warrants additional practices for earlier detection among Filipinos.