Feasibility of Identifying a Chinese Study Population and Eligible Pediatric Cancer Cases, and Linking the Two Groups to Assess the Role of Periconceptional Folic Acid Supplements in Risk of Pediatric Cancer.

Few risk factors have been consistently linked with pediatric cancer. During the past 15
years, small casecontrol epidemiologic studies in Caucasian populations have reported reduced
risks of pediatric leukemia and brain tumors in offspring of mothers treated with folic acid
and iron supplements in the prenatal and periconceptional period.

We describe a feasibility study to evaluate the potential for prospective assessment of
periconceptional and prenatal folic acid supplements and other postulated risk factors in
risk of pediatric leukemia and other pediatric cancers. If the feasibility study is
successful, we propose to carry out a prospective record linkage Children and Families Cohort
Study (CFCS) (N=243,779) to compare risk of pediatric leukemia, brain tumors and other
pediatric cancers in offspring of Chinese mothers who took vs did not take periconceptional
folic acid supplements during 1993-1995 in a community-based intervention trial that assessed
the effects on occurrence of neural tube defects. The original investigators last followed up
the population in 2000-2001 The Chinese CDC, the U.S. CDC, and NCI collaborators carried out
small pilot studies (N=560 families) during 2011-2013 demonstrating that CFCS families can be
successfully identified and traced, that mothers and offspring would participate in single
and in multi-day interviews, and that referral and community hospitals (N=8) could locate and
abstract medical records of potentially eligible pediatric cancer cases diagnosed during 1994
to the present.

The proposed feasibility study involves three components. The first component will test
success in re-creating the original CFCS offspring list in the 21 counties in three
provinces. Data collected in the original 1993-1995 study and 2000-2001 follow-up to be used
in recreating the list includes the original study ID number, sex, birth dates of offspring,
mothers and fathers, place of birth (village, township, and hospital), residence at birth,
and other identifying information; names of subjects and family members are not available on
the original study lists. This component will be undertaken in collaboration with county- and
provincial-level maternal and child health organizations that will coordinate with public
health bureaus, family planning, and public security agencies. The goal of this component is
to re-identify all of the CFCS offspring in 5 counties in Hebei Province and in 9 counties in
Jiangsu and Zhejiang Provinces, and in samples of 500 randomly selected CFCS offspring in
each of 7 counties in Jiangsu and Zhejiang Provinces.

The second component will identify all hospitals where children from the 21-county study
population would have been diagnosed or treated for pediatric cancer during 1994 to the
present. An expanded sample of these hospitals (N=10 beyond the 8 hospitals included in our
recent pilot study) will be contacted and asked to collaborate in the proposed study. Tasks
will include identification and abstraction of medical records of pediatric cancer cases
occurring in children who are potentially CFCS offspring (born during 1994-1996 in any of the
21 CFCS study counties). Mothers of the pediatric cancer patients will be interviewed and
asked to provide identifying information to ascertain if the offspring were in the CFCS
population, and to provide consent (together with their offspring s assent) for the
collaborators to have access to the medical record abstract data and to match the offspring
with the CFCS population list. The investigators will then attempt to match the potentially
eligible pediatric cancer cases with the CFCS list in the 5 counties in Hebei Province and
the 9 counties in Jiangsu and Zhejiang Provinces.

The third component will identifying deaths among offspring to ascertain those that
definitely, probably or possibly might be due to childhood cancer. For deaths among CFCS
offspring identified during the 2000-2001cohort follow-up by the original study team, cause
of death will be ascertained from death certificates if available or from medical records or
interview of primary care physicians if death certificates are not available. For deaths
among offspring who died after 2000-2001,review of death certificates among children born
during 1994-1996 in the 21 counties will be undertaken. Identifying information will be
sought from the death certificate to match the deceased child to the CFCS. If the identifying
information is insufficient for a match, for those deaths definitely, probably or possibly
due to childhood cancer, the mother of the deceased child will be traced and interviewed to
obtain additional identifying information, permission to review medical records for
hospitalizations near to the time of death, and contact information for the child s primary
care doctor. For those children who died after 2000-2001and are determined to definitely or
probably be members of the CFCS, a provisional determination will be made if the deceased
offspring definitely, probably, possibly or did not have a diagnosis of childhood cancer. The
provisional diagnoses will be reviewed by the expert pediatric
hematologists/oncologists/neurosurgeons for a final determination and assessment of level of
certainty.

- INCLUSION CRITERIA:

Eligibility and inclusion criteria are as follows for each specific aim:

Specific Aim #1. Families with a child born 1994-96 in the 21 CFCS counties and whose
family members (mother, offspring, and child) match the identifying characteristics listed
in Table 2.

Specific Aim #2. Children born during 1994-96 in the 21 CFCS counties who were diagnosed
with incident pediatric cancers during 1994 to the present

Specific Aim #3. Children born during 1994-96 in the 21 counties and members of the CFCS
population who were determined to have died during the 2000-2001 follow-up. Those eligible
for this specific aim among children not known to have died based on the 2000-2001
follow-up will include children born during 1994-1996 in the 21 counties who are found to
have died after 2000-2001 based on search of death certificates at the county- and
provincial-level CDCs. Efforts will be undertaken to determine if children who died after
2000-2001 and are potentially eligible (born 1994-1996 in one of the 21 CFCS counties) were
definitely or probably offspring members of the CFCS through review of death certificates
and interview of mothers of the deceased children. For these offspring, review and
abstracting of medical records for hospitalizations, or, if not available, interviews with
primary care doctors of the children will be undertaken to determine if the individual
definitely, probably, possibly or did not have a diagnosis of childhood cancer.