1068
classification was independent of the patient mean age at
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was a type II statistical error, and if the number of younger
patients in our cohort were greater, a difference in tumor
aggressiveness between older and younger patients may
have been evident.
3. The relatively small number of patients with cervical
lymph node involvement at diagnosis is somewhat un-
expected because locally invasive tumor is associated with
the presence of local lymph node metastases (33,34). This
may be related to the surgical approach with perhaps less
aggressiveness in lymph node resection or “berry pick-
ing” for lymph node involvement in our group. Alterna-
tively, a change in invasive characteristics with lack of
lymph node involvement may account for less frequent
lymph node involvement in our tumors.
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Our patients had a similar rate of recurrence at 10 years
compared to the patients of Mazzaferri and Oppenheimer
(10), and the difference was not statistically significant (23.8%
vs. 19.5%,
NS). However, our recurrence rate reflected a
p 5
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epidemiology of thyroid cancer in Hawaii. Cancer 61:1272–
1281.
18. Weiss W 1979 Changing incidence of thyroid cancer. J Natl
Cancer Inst 62:1137–1142.
19. Pottern LM, Stone BJ, Day NE, Pickle LW, Fraumeni JF Jr
1980 Thyroid cancer in Connecticut, 1935–1975: An analysis
by cell type. Am J Epidemiol 112:764–774.
20. Verby JE, Woolner LB, Nobrega FT, Kurland LT, McCona-
hey WM 1969 Thyroid cancer in Olmsted County 1935–1965.
J Natl Cancer Inst 43:813–820.
21. U.S. Census Bureau; DP-1. General Population and Housing
Characteristics: 1990. Data Set: 1990 Summary Tape File 1
(STF 1)—100-Percent data. Available at: http://factfinder.
census.gov/servlet/BasicFactsTable?_lang5en&_vt_
name5DEC_1990_STF1_DP1&_geo_id504000US54099 and
http://factfinder.census.gov/servlet/BasicFactsTable?_lang
5en&_vt_name5DEC_1990_STF1_DP1&_geo_id505000US
54099. Accessed: June 5, 2001.
22. U.S. Census Bureau; Table DP-1. Profile of General Demo-
graphic Characteristics. Available at: http://www.census.
gov/prod/cen2000/dp1/2kh54 pdf. Accessed: June 5, 2001.
23. Hundhal SA 1998 Perspective: National Cancer Institute
summary report about estimated exposures and thyroid
doses received from iodine 131 in fallout after Nevada atmo-
spheric nuclear bomb testing. CA Cancer J Clin 48:285–298.
24. Sarne D, Schneider AB 1996 External radiation and thyroid
neoplasia. Endocrinol Metab Clin North Am 25:181–195.
25. Pesatori AC, Consonni D, Tironi A, Zocchetti C, Fini A,
Bertazzi PA 1993 Cancer in a young population in a dioxin-
contaminated area. Int J Epidemiol 22:1010–1013.
minimum value because most of our patients have been pre-
senting in the past 3 years and our median follow-up was
only 3 years. Over the next few years, we expect more re-
currences, and our results may become significantly differ-
ent.
Thyroid cancer mortality was not significantly different
from that observed by Mazzaferri and Oppenheimer (10) in
their group, although the number of deaths was relatively
small and precluded definite conclusions. The relative mor-
tality was greater in patients with follicular cancer (2/9) than
papillary cancer (2/66) (ANOVA,
0.001).
p 5
In conclusion, the incidence of differentiated thyroid can-
cer increased dramatically in our community. Until further
studies, the implication of an environmental factor in ex-
plaining the increase remains a speculation. Although the tu-
mors appeared to have aggressive features at diagnosis,
longer duration of follow-up is needed to better assess the
prognosis of these tumors.
Acknowledgment
The authors thank Stuart W. Thomas, Jr., Ph.D. and Todd
W. Gress, M.D., M.P.H., for their assistance with the statis-
tical analyses; R. Arturo Roa, M.D., Mark F. Sheridan, M.D.,
Phillip R. Stevens, M.D., S. Kenneth Wolfe, M.D., and other
otolaryngologists and surgeons in Huntington for allowing
us to share in the care of their patients.
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