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specific survival of pediatric patients who were diagnosed with
medullary thyroid cancer was signi ficantly worse, but appeared to
bene fit from combined surgery and external beam therapy (Fig. 3).
Furthermore, patients with the papillary follicular variant at fifteen
years did not appear to derive benefit 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 fic survival based on extent of disease
at initial diagnosis and therapeutic intervention
When evaluating fifteen-year disease specific survival for each
tumor subtype based upon clinical staging of localized or distant
disease, our group identified 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 fifteen 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).
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 [1e7]. 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
significant difference in the incidence and disease specific 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 findings that were in accordance with several former
publications in the medical literature regarding the incidence of the
various carcinoma subtypes [2e6]. 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
specific survival demonstrated significantly improved outcomes if
the age at diagnosis was before nine years of age compared to in-
dividuals first diagnosed at ten or older. Our findings 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 specific 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 fit. For both
papillary and follicular thyroid carcinomas, a patient's fifteen-year
Fig. 2. Fifteen-year disease specific survival based on age group between 2007 and
2012. (For interpretation of the references to colour in this figure legend, the reader is
referred to the web version of this article.)
Fig. 3. Fifteen-year disease specific 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 figure legend, the reader is referred to the web version of this article.)
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