2017 Sec 1 Green Book

S. Dermody et al. / International Journal of Pediatric Otorhinolaryngology 89 (2016) 121 e 126

4. Discussion

Previous literature reporting pediatric thyroid carcinoma out- comes have demonstrated the importance of early diagnosis and prompt initiation of therapy in order to yield favorable survival outcomes [1 e 7] . After assessing the current literature, our group wished to update the medical community with recent data from the SEER Database, analyzing pediatric thyroid carcinomas from 2007 to 2012. Furthermore, we wished to determine if there is any signi fi cant difference in the incidence and disease speci fi c survival outcomes based on individual cancer subtypes between the years of 2007 and 2012. To the best of our knowledge, this study provides the medical community with the most recent analysis of the SEER Database with regard to pediatric thyroid cancer. After evaluating the SEER Database for the most common thy- roid cancer subtypes in the pediatric population, our study eluci- dated fi ndings that were in accordance with several former publications in the medical literature regarding the incidence of the various carcinoma subtypes [2 e 6] . Overall, the incidence of pedi- atric thyroid cancer appears to be increasing at an average age- adjusted rate of approximately one percent when the four most common malignancies were taken into account ( Fig. 1 ). Addition- ally, after evaluating the pattern of cancer predominance based upon age cohort, it is apparent that medullary and papillary thyroid carcinoma incidence are the most frequent before ten years of age and the incidence of papillary carcinoma increases as one enters the teenage years. Interestingly, our group determined that be- tween the years 2007 and 2012, patients at fi fteen-year disease speci fi c survival demonstrated signi fi cantly improved outcomes if the age at diagnosis was before nine years of age compared to in- dividuals fi rst diagnosed at ten or older. Our fi ndings parallel those reported in previous medical literature and remain stable since last SEER dataset was published [3,6] . In order to further expand on disease speci fi c survival, our group analyzed the four most common pediatric thyroid cancer subtypes and determined if surgery alone or in combination with adjuvant radiation therapy provided additional bene fi t. For both papillary and follicular thyroid carcinomas, a patient's fi fteen-year

Fig. 2. Fifteen-year disease speci fi c survival based on age group between 2007 and 2012. (For interpretation of the references to colour in this fi gure legend, the reader is referred to the web version of this article.)

speci fi c survival of pediatric patients who were diagnosed with medullary thyroid cancer was signi fi cantly worse, but appeared to bene fi t from combined surgery and external beam therapy ( Fig. 3 ). Furthermore, patients with the papillary follicular variant at fi fteen years did not appear to derive bene fi t from surgery with adjuvant radiation therapy compared to surgery alone when evaluated at yearly intervals (P ¼ 0.763, 0.689, 0.829, 0.629, 0.728). 3.5. Fifteen year disease speci fi c survival based on extent of disease at initial diagnosis and therapeutic intervention When evaluating fi fteen-year disease speci fi c survival for each tumor subtype based upon clinical staging of localized or distant disease, our group identi fi ed that patients diagnosed with localized papillary, follicular, and papillary follicular thyroid carcinoma demonstrated excellent outcomes after combined surgery with radiation. Regardless of subtype, patients demonstrated statisti- cally worse outcomes at fi fteen years if the initial diagnosis included distant metastases to bone, lung and brain, especially in the medullary thyroid cohort, despite surgery and adjuvant radia- tion therapy (p < 0.05) ( Fig. 4 ).

Fig. 3. Fifteen-year disease speci fi c survival for each thyroid carcinoma subtype between 2007 and 2012 (A: Papillary, B: Papillary follicular Variant, C: Follicular, D: Medullary; blue: Surgery, red: Surgery and adjuvant radiation). (For interpretation of the references to colour in this fi gure legend, the reader is referred to the web version of this article.)

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