Present Status of Childhood Thyroid Carcinoma in Belarus
following the Chernobyl Accident
Akira SUGENOYA, Yuri E. DEMIDCHIK, Evgeny P. DEMIDCHIK
Belarus National Thyroid Cancer Canter,
Skoriny av. 64, Minsk 220600, Belarus
according to the final report of the Vienna
international conference, several thousands of patientswith thyroid cancer, who were less then 15 years oldat the time of the Chernobyl disaster, may appear in
the future although scientific proof is difficult.
Considering seriousness of the prediction, appropriate
measures should be taken as soon as possible in thesehighly contaminated countries.
In the present report, we provide the resent statusof pediatric thyroid cancer in Belarus. In 1990 after
the Chernobyl breakdown, the government of Belarus
established the National Thyroid Cancer Center
following a rapid increase of childhood thyroid
carcinoma, as a special institute for not only clinicalservices but also basic researches. Dr. Demidchik E.P.,
a professor of the department of Oncology, Minsk
Medical Institute was elected the director of theCenter. Additionally, it has been also decided thatsurgery for all cases of the pediatric thyroid cancer in
Belarus

Introduction
In April, 1996, a joint international conference("One Decade after Chernobyl") was held in Vienna,
Austria in cooperation with the International Atomic
Energy Agency (IAEA), the World HealthOrganization (WHO) and the European Commission(EC).
In this meeting, they came to the conclusion thatthe abnormality of health condition definitely related
to the Chernobyl accident was only thyroid cancer inchildren for the moment. On the other hand, theyreported that it would be too early to give commentsscientifically on leukemia and other disorders.
It has been already known that the incidence ofpediatric thyroid cancer in Belarus, Ukraine and theRussian Federation is rapidly increasing after 1990.
About 800 children in these 3 CIS countries havebeen treated surgically until the end of 1995. Morethan half of them were found in Belarus. Furthermore,

Table 1. Number of thyroid cancer in Belarus before and after the Chernobyl Accident
Period1975-1985
1986-1996

Adults(more than 15)
1,342
4,006

Children(under 15)
7508

Table 2. Age distribution of children with thyroid cancer in 1986-1995 (age at the time of theaccident)
RegionTotalpopulation*,thousands

Brest region
Vitebsk region
Gomel region
Grodno region
Minsk region
Mogilev region
Minsk city

1,520
1,300
1,670
1,160
1,410
1,270
1,630

Belarus9,960

Number of
thyroid cancer
children

%

0-4

5-9

10 14

97
7225
24
20
21
26

68
4
149
12
14
14
17

27
372
11
5
6
8

2
0
4
1
1
1
1420

278

132

10100

66.2

31.4

2.4

* Adult people is included (data in 1986).
This report was published in Gijutsu-to-Ningen, No.281,
pp.36-40, Nov. 1997 (in Japanese).

165

Number of cancer by age

pre-accident, at the time of the accident andpost-accident, 497 cases belong under thepre-accident group (97.8%), 6 under the time of theaccident (1.2%), and 5 under the post-accident group(1.0%). It has been clarified that most of the children
are grouped into the pre-accident category.
The age distribution at the time of the Chernobyl
breakdown in 420 children operated until 1995,
demonstrated as follows: 0-4 years old was 66.4%,
5-9 years old - 31.4%, and 10-14 years old - 2.4%.
More then half of the patients were classified into
markedly young-aged population (Table 2 and Fig. 2).
Four children born after the accident were excluded.
The annual frequency of the pediatric thyroid
cancer in Belarus before the accident was 0.1 per
100,000 children, which is almost the same level as allover the world. However, after the accident, thoselevels were gradually elevating: i.e., 1.2 in 1990, 2.8
in 1992, 3.5 in 1994, 4.0 in 1995, and 3.8 in 1996. In
the highly contaminated Gomel Region, the yearly
incidence after the breakdown was as follows: 3.6 in1990, 11.3 in 1991, 13.4 in 1995 and 12.0 in 1996,
respectively. All of these values after 1991 were morethan 100 times compared with that of the world. In
Brest region, the incidence in 1996 was also high, 7.3.
On the other hand, in Vitebsk Region, the lesscontaminated area, no pediatric thyroid cancer has
been found since 1993.
These several clinicoscientific data shown here
strongly suggest that childhood thyroid carcinoma
rapidly increasing in Belarus has been attributed toradioactive contamination by the Chernobyl accident.
In particular, radioactive iodine would be a main
carcinogenic factor on the thyroid gland.
Physiologically, the thyroid gland concentrates iodine
for the synthesis of thyroid hormone. It is, therefore,generally accepted that radiation-induced thyroid

should be performed here at the Center. The data
described herein were composed of the operative
results in those children with histopathological proofof thyroid cancer after surgical treatment at theCenter.

Childhood thyroid carcinoma in Belarus after
Chernobyl
The number of patients with thyroid cancer in bothchildren and adults in Belarus is shown in Table 1.
During the 11 years before the Chernobyl explosion(1975-1985), there were only 7 cases of pediatricthyroid cancer. However, in the same duration after
the accident (1986-1996), the number of pediatricpatients was 508 with remarkable increase, which was
72 times compared with the pre-accident period.
Meanwhile, with respect to adult patients, the numberof thyroid cancer in the former period was 1,342 andin the latter - 4,006. It increased in about 3 times
compared with the pre-accident duration. In cases ofadults, the increase of the incidence of thyroid cancer
might be due to not only the recent improvement of
diagnostic procedures, but also the frequent medical
examinations after the accident. It is, therefore,
necessary to continue more precise and detailed
investigations in the future.
When all of the 508 children with thyroid cancer
are classified with accord to their birth places(Regions in Belarus) as depicted in Fig. 1, there isfound an apparent geographical feature proving thatthe majority of pediatric patients was born in thehighly contaminated areas; 268 patients in Gomel
Region (52.8%) and 122 in Brest Region (24.0%).
Furthermore, dividing their birthday into 3 groups; i.e.

Vitebsk●
7● Grodno

29●●●Minsk56

Mogilev 26
Gomel ●
268

Brest 122★
Chernobyl NPP

Fig. 1 Geographical distribution of child thyroid cancer in Belarus (1986-1996: 508 cases)
166

2.4%
31.4%

420
66.2%

Fig. 2

Age
0-4
5-9
10-14

Age structure of children with thyroid cancer (age at the time of the accident)
about marriage, pregnancy and delivery. Moreover,they really fear hereditary effects on their new-bornbabies. Some of them, therefore, are considering toavoid marriage and/or delivery.
Judging from these sad matters, healthconsequences of the Chernobyl disaster havedefinitely just emerged. Hence it appears thatsocio-psychosomatic cares will become exceedingly
crucial means in the near future for not only children
in the growing-up stage, but also their parents. We
should keep in mind that there is a need for
educational programs of this aspects as a trial of
humanitarian medical supports.

cancer after a radionuclide-releasing event would beinitiated through this pathway. However, the exact
and precise mechanisms of carcinogenesis have notbeen elucidated yet. Moreover, it is also extremely
difficult to prove the initiation process of carcinoma
directly. Further basic investigations should beextensively continued.
The recent change in childhood thyroid carcinoma
has demonstrated a gradual decrease of the patientnumber showing 91 cases in 1995, 84 in 1996 and 27
till the end of May 1997. On the contrary, teenager
patients with thyroid cancer older then 15 years old
are apparently increasing since 1993; i.e., 4 cases in
1990, 1 in 1991 and 1992, 25 in 1993, 21 in 1994, 25in 1995, and 26 till the end of October 1996,
respectively. In this teenager group, the samegeographic characteristic is also observed as thechildren previously described; that is, 70% of theoperated patients have been sent to this Center fromboth Gomel and Brest Regions. These facts suggestthat the incidence of thyroid malignancy in teenagers
and young adults progressively is increasing insteadof children.

References
1. ONE DECADE AFTER CHERNOBYL: Summing
Up the Consequences of the Accident, Proceedingsof an International Conference, Vienna, 8-12 April
1996, IAEA STI/PUB/1001.
2. Kazakov V.S., Demidchik E.P., Astakhova L.N.
et.al., Thyroid Cancer after Chernobyl, Nature 359,
21-22, 1992.
3. Socalow E.L., Hashizume A., Nerishi S. et al.,Thyroid Carcinoma in Man after Exposure to
Ionizing Radiation, N.Engl.J.Med., 268, 406-410,
1963.
4. Maron H., Thomas S., Saenger E., et al., Ionizing
Radiation and the Induction of ClinicallySignificant Disease in the Human Thyroid Gland,
Am.J.Med., 63, 967-978, 1997.

Problems for the near future
At present, those patients with thyroid carcinoma
who had undergone radical surgery at the time of theirchildhood are reaching adolescence or youth. They
are carefully thinking over their own future life.
Particularly, young women are seriously worrying

167