Yu. Demidchik, M. Fridman

Childhood Thyroid Cancer in Belarus Following the Chernobyl Accident

Part 1

THYROID CANCER STATISTICS– Two etiological forms (radiogenic and sporadic)– High incidence in children within the first decade after

Chernobyl• Since 2001, only sporadic cases were diagnosed

– Prevalence of PTC• Follicular, medullary or anaplastic carcinomas are extremely

rare– Recently, about 50% of patients present micro

carcinomas at diagnosis

Crude incidence and mortality for thyroid cancer (:100 000) (1965–2013)

19651967

19691971

19731975

19771979

19811983

19851987

19891991

19931995

19971999

20012003

20052007

20092011

20130

2

4

6

8

10

12

14In total, 23795 patients were diagnosed from 1970

Mortality rates are available only since 1990

(1747 patients died within 1990-2013)

Crude incidence and mortality for thyroid cancer in males (:100 000) (1970–2013)

19701972

19741976

19781980

19821984

19861988

19901992

19941996

19982000

20022004

20062008

20102012

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

Crude incidence and mortality for thyroid cancer in females (:100 000) (1970–2013)

19701972

19741976

19781980

19821984

19861988

19901992

19941996

19982000

20022004

20062008

20102012

0

5

10

15

20

25

Incidence increased by 8 times as compared with 1986

19701973

19761979

19821985

19881991

19941997

20002003

20062009

20120

5

10

15

20

25

30

BrestVitebskGomelGrodnoMinskMogilevMinsk city

Crude incidence (: 100 000) for thyroid cancer in different regions (1970–2013)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

00-14 15-19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 65-69 70-74 75-79 80+

Crude incidence (: 100 000) for thyroid cancer depending on age group (1970–2013)

Part 2

THYROID CANCER IN CHILDREN– 1418 cases of thyroid carcinomas (under 19 y.o.)

were diagnosed in the period from 1986 and 2010 (all histological forms).

– Of them, 1169 are available for assessment.– The individuals born after April, 1987 were

considered as non-radiogenic.

00,20,40,60,8

11,21,41,61,8

2

1986 1987 1988 1989 1990

Cru

de in

ciden

ce 1

05

years

The beginning of significant increase of incidence in exposed to 131I

0

1

2

3

4

5

6

1986 1987 1988 1989 1990 1991 1992C

rude

incid

ence

105

years

Aged under 18 Aged over 19

19701972

19741976

19781980

19821984

19861988

19901992

19941996

19982000

20022004

20062008

20102012

0.00

2.00

4.00

6.00

8.00

10.00

12.00

14.00

16.00

00-14 15-19 20-24 25-29

?

Crude incidence (: 100 000) in young age (1970–2013)

19701973

19761979

19821985

19881991

19941997

20002003

20062009

20120

2

4

6

8

10

12

14

BrestVitebskGomelGrodnoMinskMogilevMinsk city

Childhood crude incidence (: 100 000) for thyroid cancer in different regions (1970-2013)

19701973

19761979

19821985

19881991

19941997

20002003

20062009

20120

5

10

15

20

25

30

35

40

BrestVitebskGomelGrodnoMinskMogilevMinsk city

Adolescent crude incidence (: 100 000) for thyroid cancer in different regions (1970-2013)

Post Chernobyl thyroid cancer cases in children depending on place of residence at the time of Chernobyl accident (1986-2005)

Thyroid cancer in Belarus Results of Screening

Study Area Age group PeriodCases Prevalence

male female Total male female Total

IPHEKA (Scientific report, 1996) Gomel region

Children and adolescents at the time of accident

1990–1992 — — 15 — — 15/6946

2.16/1000

Sasakawa (Proceedings of the 5th Chernobyl Sasakawa Medical Cooperation Symposium, 1996)

Gomel region

Up to 9 years at the time of accident

1991–1996 12 25 37 12/9485

1.27/100025/101752.46/1000

37/196601.88/1000

Sasakawa (Proceedings of the 5th Chernobyl Sasakawa Medical Cooperation Symposium, 1996)

Mogilev region

Up to 9 years at the time of accident

1991–1996 1 1 2 1/11663

0.09/10001/12118

0.08/10002/23781

0.08/1000

Belarus screening program (Drozd V. M., 2003) Belarus

Up to 14 years at the time of accident

1990–1991 — — 7 — —

7/11006.36/1000

Belarus screening program (Krysenko N. A., 2003)

Gomel region

Up to 14 years at the time of accident

2002

— — 0 — —0/254460/1000

15–18 years at the time of accident

— — 2 — —2/12129

0.17/1000

1999 2000 2001

n 151015 150381 144765

NODULES542 495 393

0.36% 0.33% 0.27%

OF THEM CANCER

10 9 3

1.85% 1.82% 0.76%

CHILDREN (under 15)

17

1999 2000 2001

n 44859 49064 57068

NODULES513 547 655

1.14% 1.11% 1.15%

OF THEM CANCER

6 11 21

1.17% 2.01% 3.21%

ADOLESCENTS (15–18 yo)

1999 2000 2001

n 96928 100169 80541

NODULES7405 7635 7195

7.64% 7.62% 8.93%

OF THEM CANCER

299 298 237

4.01% 3.92% 3.29%

ADULTS (19+ yo)

POST CHERNOBYL (RADIOGENIC) PATIENTS-1

Total number of cases: 936 (non-PTC cases and irradiated previously for other malignancies excluding)

– Females: 600 (64.1%)– Males: 336 (35.9%)– Ratio: 1.8:1

Age: 4.2 – 18.99 (13.6)– Under 10 y.o.: 157 (16.8%)– 11-14 y.o.: 364 (38.9%)– 15-18 y.o.: 415 (44.3%)

POST CHERNOBYL (RADIOGENIC) PATIENTS-2

• Tumor size– Average: 14.4 mm (range 1-124 mm)

• From 1 to 5 mm: 84 cases• From 6 to 10 mm: 302 • Above 11 mm: 550 (58.8%)

• Involved lymph nodes– N0 :246 (26.3%)– N1a:309 (33.0%)– N1b:381 (40.7%)

(41.2%)

(73.7%)

POST CHERNOBYL (RADIOGENIC) PATIENTS-3

• Distant metastases at primary diagnostics — 104 (11.1%).

• Extrathyroidal extent – 387 (41.3%). !Note!

In 262 (28.0%), the capsular involvement is not assessed.

• Multifocality – 60 (6.4%)

POST CHERNOBYL (RADIOGENIC) PATIENTS-4

• Pathological features– Classical PTC – 360 (38.5%)– Follicular variant – 292 (31.2%)– Diffuse sclerosing variant – 73 (7.8%)– Tall cell – 65 (6.9%)– Clear cell – 10 (1.1%)– Solid – 136 (14.5%)

• Involved blood vessels – 176 (18.8%)• Involved lymphatic vessels – 790 (84.4%)

POST CHERNOBYL (RADIOGENIC) PATIENTS-5

• Thyroid background – 148 (15.8%), including– Autoimmune thyroiditis – 72– Follicular adenoma – 20– Nodular goiter – 56

• Dominant architectonics – Papillary – 300 (32.1%)– Follicular – 453 (48.4%)– Solid – 183 (19.6%)

CONCLUSION#1

Post Chernobyl (radiogenic) PTC is frequently extrathyroidal. The tumor size in largest measurement is usually small but associated with high frequency of neck lymph nodes involvement (73.7%) and distant metastases (11.1%)

TOTAL THYROIDECTOMY+

BILATERAL SELECTIVE NECK DISSECTION (LEVELS VI, II-IV)

RADIOIODINE UPTAKE I-131

RADIOIODINETHERAPY

L-T4SUPRESSIVE THERAPY

Multivariate analysis of local or regional recurrence

Variables β p-value RR 95% CI

Age at surgery 0.5855 0.1041 1.80 0.88-3.64

Multifocal carcinomas 1.0762 0.0049 2.93 1.39-6.21

N1b 0.5920 0.0361 1.81 1.04-3.14

Involved blood vessels 0.4734 0.0976 1.61 0.92-2.81

Involved lymphatic vessels 1.2845 0.0900 3.61 0.82-15.95

Thyroid background -1.0669 0.1461 0.34 0.08-1.45

Intrathyroidal dissemination 0.6483 0.0309 1.91 1.06-3.45

Thyroid lobectomy 1.8122 <0.0001 6.12 3.38-11.11

The risk of recurrence

CONCLUSION#2

• Local or regional recurrence after thyroidectomy is likely for 5 years and distant metastases can spread for 6 years.

• In cases of surgery other than thyroidectomy, the probability of local or regional recurrence is high in any terms of follow-up.

• Distant metastases can be detected within 10 years after partial thyroid resections.

Fine Grey regression model for distant metastases

Variables β p-value RR 95% CI

Childhood age at surgery 6.13 0.0150 6.13 1.43 – 26.3

Involved blood vessels 2.16 0.0002 8.68 2.75 – 27.4

No RIT 2.23 0.0003 9.26 2.74 – 31.2

CONCLUSION#3

• To avoid local or regional recurrence in children and adolescents with PTC, primary surgery has to be based on total thyroidectomy followed by radioiodine therapy depending on indications

• Despite this strategy, distant metastases can appear 5-6 years after surgery being associated with tumor peculiarities: involved blood vessels, patients’ age and refusal from radioiodine

Part 3

SPORADIC THYROID CANCER IN CHILDREN

No clear evidence of geographical factor in sporadic cases (n=210; 1986–2010)

Differences between sporadic and radiogenic cancer

Sporadic carcinomas were significantly more common on abnormal thyroid background.

In sporadic cases, lung metastases are significantly less common as compared with radiogenic carcinomas (2 cases; 1.4%).

Crude incidence in different periods and age groups

Age groupRadiogenic Sporadic

1990–1995 1996–2001 2002–2005 2005–2010

0–18 2.72 3.22 1.29 1.16

0–14 2.88 2.24 0 0.62

15–18 2.09 6.24 4.48 2.54

Observed survival (96.9%)

0 2 4 6 8 10 12 14 16 18 20 22 24 26 280

10

20

30

40

50

60

70

80

90

100

p=0.8763

Годы

ОВ

, [%

]

Causes of death in 26 pts

• Cause specific death: 2• Acute leukemia: 2• Gastric cancer: 1 (totally 10 pts have second cancer)• Accidents and traumatic lesions: 6• Suicide: 7• Surgical complications: 1• Lung fibrosis: 1 • Liver cirrhosis: 1• Cardiac failure: 1 +2 sporadic• Mixedema: 1 • Brain infarction: 1

CONCLUSION#4

The prognosis in childhood and adolescent thyroid cancer is favorable.

Acknowledgment

• Dr. Yu. Averkin • Prof. D. Williams• Prof. K. W. Schmid• Prof. C. Reiners• Dr. M. Fridman• O. Krasko

THANK YOU

FOR ATTENTION!