ML071290155

(NPA-PD) Letter to Mary Lampert from the Commonwealth of Massachusetts Executive Office of Heath and Human Services, Department of Public Health, Regarding Child Heath Statistics

ML071290155
Person / Time
Site:	Pilgrim
Issue date:	05/09/2006
From:	Sullivan J State of MA, Dept of Public Health
To:	Lampert M - No Known Affiliation, Office of Nuclear Reactor Regulation
References
TAC MD3698
Download: ML071290155 (13)

Text

The Commonwealth of Massachusetts Executive Office of Health and Human Services Department of Public Health 250 Washington Street, Boston, MA 02108-4619 MITT ROMNEY GOVERNOR KERRY HEALEY LIEUTENANT GOVERNOR TIMOTHY R. MURPHY SECRETARY PAUL J. COTE, JR.COMMISSIONER May 9, 2006 Mary Lampert

Dear Ms. Lampert:

This letter is a response to your recent email to Bob Knorr at the Massachusetts Department of Public Health (MDPH) requesting child health statistics.

Enclosed are data on childhood cancer and low birthweight in Duxbury, Kingston, Marshfield and Plymouth around the Pilgrim Nuclear Power Station. Dr. Knorr forwarded your inquiry to the Community Assessment Program (CAP), a division within the Center for Environmental Health (CEH) at the MDPH, which responds to requests such as yours. Enclosed with this letter please find eight tables that summarize the data we are able to provide to you.Tables 1-3 summarize the incidence of all childhood cancers in four communities (Duxbury, Kingston, Marshfield and Plymouth) during three separate time periods (1982-1988, 1989-1995 and 1996-2002).

Childhood cancer is defined as all invasive, primary cancers diagnosed in children aged 0 to 19 years at diagnosis.

[For an explanation of how the Standardized Incidence Ratio (SIR) was calculated and how to interpret it, please see the attachment entitled Explanation of a Standardized Incidence Ratio (SIR) and 95% Confidence Interval.]

Tables 4-7 are a summary of the different cancer types diagnosed in each time period by town. In a March 2003 MDPH Center for Health Statistics, Research and Evaluation report entitled Childhood Cancer in Massachusetts 1990-1999, the three most common cancers among all Massachusetts children and adolescents less than 20 years old were leukemia (23.8%), lymphomas (18.6%,. which include Hodgkin's disease and other lymphomas), and central nervous system cancers (17.4%, which include brain cancer and other CNS tumors). Similarly, in a 1999 federal report entitled Cancer Incidence and Survival among Children and Adolescents:

United States SEER Program 1975-1995, the highest childhood cancer rates were for leukemia, lymphomas, and brain/CNS cancers.

Table 8 summarizes the percentage of low birthweight babies out of the total number of births in each of the same four communities along with the overall percentage of low birthweight babies for the state for comparison.

Low birthweight is defined as any newborn who weighted less than 2500 grams (5 lbs. 8 oz.) at birth.The following is a summary based upon a review of these data: For 1982-1988, with two exceptions, the number of observed diagnoses of childhood cancers was less than the number expected.

In Marshfield there were five diagnoses of childhood cancer observed in males compared to four expected and in Kingston there were two diagnoses observed in females compared to one expected; however, the differences were not statistically significant.

For 1989-1995, in each of the four communities, in some instances, the number of observed diagnoses exceeded the number expected; the differences; however, were not statistically significant.

In Duxbury females, three diagnoses of childhood cancer were observed versus approximately -two expected.

In Kingston among males and females combined, six diagnoses of childhood.

cancer were observed versus approximately three expected.

In Marshfield, more females were diagnosed with childhood cancer than expected (6 observed versus 3.1 expected) and fewer males were diagnosed than expected (1 observed versus 4.1 expected).

In Plymouth, the number of overall childhood cancers slightly exceeded the number expected (16 observed versus 15.3 expected).

• For 1996-2002, for the three communities of Duxbury, Kingston, and Marshfield, the number of observed diagnoses of childhood cancer was consistently lower than the number expected.

In Plymouth males and females, childhood cancer rates were higher for both males and females. However, the differences were not statistically significant." As seen in Tables 4-7, the types of childhood cancers diagnosed duririg 1982-2002 were generally consistent with state and national trends, with the most common diagnoses of leukemia, Hodgkin's disease, and brain/CNS cancers being consistent with state and national trends. There were a few exceptions.

As seen in Table 4, no childhood diagnoses of brain/CNS cancer were reported in Duxbury over the 21-year time period whereas two diagnoses of bone cancer were reported over a 14-year time period. Also, as seen in Table 6, four diagnoses of bone cancer occurred in Marshfield over the 21-year time period. Finally, as seen in Table 7, three diagnoses of thyroid cancer occurred in Plymouth during the 1996-2002 period. Due to the observation of three thyroid diagnoses in Plymouth during the latest seven-year time period, we evaluated the geographic distribution of their place of residence.

The three individuals with thyroid cancer resided approximately six to 12 miles apart. One individual diagnosed resided in the north of Plymouth, one in the east, and one in the southern portion of Plymouth.2 If you have any questions regarding the information that is enclosed in this letter, please feel free to contact me at (617) 624-5757.Sincerely, Jan Sullivan, Director Community Assessment Program Center for Environmental Health Enclosures CC: Suzanne Condon, Associate Commissioner, MDPH Martha J. Steele, Deputy Director, CEH Bob Knorr, Director, Environmental Epidemiology, CEH 3 TABLE 1 Childhood Cancer Incidence Duxbury, Kingston, Marshfield

& Plymouth, MA 1982-1988 i Town' ~ ~ Total M '~I'ales Females__________________

O>' bsj' Exp rSIR 79~5% CII O~bs~ Ex SIR7 95% CI Obs Ep SR 9%C Duxbury 3 4.5 NC NC --. NC 1 2.4 M NC NC- NC 2 2.0 NC NC -- NC Kingston 2 2.7 NC NC -- NC 0 1.5 NC NC-- NC 2 1.2 -NC NC -- NC Marshfield 7 7.3 96 39 -- 199 5 4.0 126 41 -- 295 2 3.3 NC NC -- NC Plymouth 8 13.6 59 25 --116 4 7.4 NC NC-- NC 4 6.2 NC NC-- NCýNote: SIRs are calculated based on the exact number of expeceted cases, Expcte nmbe o caesp~resented aerounded tothe 4 nearest tenth.SIRs and 95% CI are not calculated when observ~ed numi~ber of 'cases < 5.Ohs = Observed number of cases 195% Cl = 95% Confidence Interval Exp = Expected nu~mber of cases, NC, =,N~~4ot calculated SIR = Standardized Incidence Ratio ><~' ~

• Statistical significance.

Data Source: Massachusetts Cancer Registry, Center for Health Information, Statistics, Research and Evaluation, Massachusetts Department of Public Health.

TABLE 2 Childhood Cancer Incidence Duxbury, Kingston, Marshfield

& Plymouth, MA 1989-1995 Town .Total i Males 7 ..Females..*

OsObs Exp SIR 95% C 0s Exp:7 SIR , 95% I Obs Exp 7 SIR .95% L/Duxbury 4 4.7 NC NC -- NC 1 2.6 NC NC-- NC 3 2.0 NC NC -- NC Kingston 6 3.0 199 73 -- 432 4 1.7 NC NC-- NC 2 1.3 NC NC -- NC Marshfield 6 7.2 .97 39 -- 200 1 4.1 NC 'NC-- NC 6 3.1 191 70 -- 416 Plymouth 16 15.3 104 60 -- 169 10 8.6 116 56 -- 214 6 6.7 89 33 -- 194 Note: SIRs are, calculated b~ased on the exact ~number of expce ae Expected number of cases presented are roundedto the nearest tenth.SIRs and 95%o CIare not calculated when obseried nhumber of cases < 5.Obs =sObserved number of SESxp =Expectedinumber of case ISIR = Standardiz~ed Incidence Ratio'95% CI =95% Conifidence Interval NC = Not calculated

• =Statistical significance Data Source: Massachusetts Cancer Registry, Center for Health Information, Statistics, Research and Evaluation, Massachusetts Department of Public Health.

TABLE 3 Childhood Cancer Incidence Duxbury, Kingston, Marshfield

& Plymouth, MA 1996-2002 Town~ Total ~Males ~ Females~SObs~ Exp SIR /95% CI >Ob~s ~Exp <SIJI 95% CI Obs~ Exp~ SIR~ 95% CI Duxbury 3 5.1 NC NC --1 2.7 NC NC-- NC 2 2.4 NC NC-- NC Kingston 2.. 3.9 NC NC --NC 0 2.1 NC NC-- NC 2 1.8 NC NC-- NC Marshfield 5 8.2 61 20 -- 143 4 4.4 NC NC-- NC 1 3.8 NC NC-- NC Plymouth 20 16.6 120 74 -- 186 11 8.9 124 62 -- 221 9 7.7 117 53 -- 222 Data Source: Massachusetts Cancer Registry, Center for Health Information, Statistics, Research and Evaluation, Massachusetts Department of Public Health.

TABLE4 Number of Different Cancer Types Duxbury 1982-2002.>Cancer Time Period S1982ý-119818 1989-1995 1996-2002 Totals Leukemia I -1 Hodgkins 1 -1 Bone -1 1 2 Ovarian I -1 1 Testicular

-1 1 Melanoma 1 -1 AllOther Types 1 2 3 TABLE 5 Number of Different Cancer Types Kingston 1982-2002 Cancer__ Time Period,"~ K1982-19,88, 1989-1995 1996-2002 Totals Leukemia 1 1 -2 Brain/CNS 2 -2 Hodgkins 1 -I Bone -1 1 Ovarian --1. 1 Melanoma -1 1 Stomach 1 -1 TABLE 6 Number of Different Cancer Types Marshfield 1982-2002 Cancer, ".:Time ,P-eriod:,',ý-,ý.", 1982-1988 v1989'-1f99-196202Totals Leukemia 1 --1 Brain/CNS 1 1 1 3 Hodgkins -1 1 2 Bone 2 1 1 4 Thyroid 1 1 Testicular 1 1 Kidney -1 1 All Other Types 1 3 1 5 TABLE 7 Number of Different Cancer Types Plymouth 1982-2002 Cancer Time Period._____________1982-1988 1989-1995~

199~6-2002 Totals Leukemia .2 3 4 9 Brain/CNS 1 3 4 8 Hodgkins 2 2 1 5 Bone 1 Thyroid -3 3 Ovarian 1 1 Oral/Pharynx

-1 1 2 NHL -1 1 2 Kidney -1 1 Larynx 1 -1 Colon/Rectum 1 --1 All Other Types 1 4 5 10 TABLE 8 Percentage of Low Birthweight Babies (<2500 grams) in Total Births Duxbury, Kingston, Marshfield, and Plymouth, MA 1989-2003 Year P juxbury Kington Ma rsbield~ ~Plymouth Massachusetts 1989 3.1 N/At 4.2 3.2 5.9 1990 5.1 5.2 4.8 5.7 5.8 1991 7.0 6.3 3.2 5.4 5.9 1992 5.4 6.3 2.9 4.4 5.9 1993 5.3 5.2 4.0 5.1 6.2 1994 5.0 3.4 4.1 5.3 6.4 1995 3.6 4.2 3.1 4.6 6.3 1996 3.7 4.5 3.0 5.8 6.4 1997 5.2 4.7 5.4 6.2 7.0 1998 N/At 3.6 3.7 4.7 7.0 1999 5.2 8.3 4.7 4.2 7.1 2000 6.9 5.1 5.9 5.9 7.0 2001 4.4 8.6 5.8 5.2 7.2 2002 7.5 3.9 5.3 8.1 7.5 2003 5.6 3.4 4.0 6.3 7.6 tN/A: Not Available due to small numbers and protection of confidentiality.

Data Source: MassCHIP, Center for Health Information, Statistics, Research and Evaluation, Massachusetts Department of Public Health.

Explanation of a Standardized Incidence Ratio (SIR)And 95% Confidence Interval In order to evaluate cancer incidence a statistic known as a standardized incidence ratio (SIR) was calculated for each cancer type. An SIR is an estimate of the occurrence of cancer in a population relative to what might be expected if the population had the same cancer experience as some larger comparison population designated as "normal" or average. Usually, the state as a whole is selected to be the comparison population.

Using the state of Massachusetts as a comparison population provides a stable population base for the calculation of incidence rates. As a result. of the instability of incidence rates based on small numbers of cases, SIRs were not calculated when fewer than five cases were observed.Specifically, an SIR is the ratio of the observed number of cancer cases to the expected number of cases multiplied by 100. An SIR of 100 indicates that the number of cancer cases observed in the population evaluated is equal to the number of cancer cases expected in the comparison or "normal" population.

An SIR greater than 100 indicates that more cancer cases occurred than expected and an SIR less than 100 indicates that fewer cancer cases occurred than expected' Accordingly, an SIR of 150 is interpreted as 50% more cases than the expected number; an SIR of 90 indicates 10% fewer cases than expected.Caution should be exercised, however, when interpreting an SIR. The interpretation of an SIR depends on both the size and the stability of the SIR. Two SIRs can have the same size but not the same stability.

For example, an SIR of 150 based on 4 expected cases and 6 observed cases indicates a 50% excess in cancer, but the excess is actually only two cases. Conversely, an SIR of 150 based on 400 expected cases and 600 observed cases represents the same 50% excess in cancer, but because the SIR is based upon a greater number of cases, the estimate is more stable. It is very unlikely that 200 excess cases of cancer would occur by chance alone.To determine if the observed number of cases is significantly different from the expected number or if the difference may be due solely to chance, a 95% confidence interval (CI) was calculated for each SIR. A 95% CI assesses the magnitude and stability of an SIR. Specifically, a 95% CI is the range of estimated SIR values that has a 95%probability of including the true SIR for the population.

If the 95% CI range does not include the value 100, then the study population is significantly different from the comparison or. "normal" population. "Significantly different" means there is less than 5% percent chance that the observed difference is the result of random fluctuation in the number of observed cancer cases.For example, if a* confidence interval does not include 100 and the interval is above 100 (e.g., 105-130), then there is statistically significant excess in the number of cancer cases. Similarly, if the confidence interval does not include 100 and the interval is below 100 (e.g., 45-96), then the number of cancer cases is statistically significantly 1 Source: Massachusetts Department of Public Health, Center for Environmental Health (December 19.98)

,I lower than expected.

If the confidence interval range includes 100, then the true SIR may be 100, and it cannot be concluded with sufficient confidence that the observed number of cases is not the result of chance and reflects a real cancer increase or. decrease.Statistical significance is not assessed when fewer than five cases are observed.In addition to the range of the estimates contained in the confidence interval, the width of the confidence interval also reflects the stability of the SIR estimate.

For example, a narrow confidence interval (e.g., 103--115) allows a fair level of certainty that the calculated SIR is close to the true SIR for the population.

A wide interval (e.g., 85--450), leaves considerable doubt about the true SIR, which could be much lower than or much higher than the calculated SIR. This would indicate an unstable statistic.

2 Source: Massachusetts Department of Public Health, Center for Environmental Health (December 1998)