Guidelines for the mapping of cancer registry data: results from a breast cancer expert panel study.
BACKGROUND
Small area (eg, subcounty) cancer mapping is one of the analytic services most commonly requested of cancer registries and local public health agencies, and difficulties in providing it have been noted to undermine public confidence. Although a great many statistical protocols have been published to enable this practice, none of them are in common use to generate information for the general public.


OBJECTIVE
To evaluate the utility of subcounty breast cancer mapping and articulate guidelines and a possible protocol for its implementation by cancer registries and local public health agencies.


METHODS
We convened an Expert Advisory Group of breast cancer stakeholders from around California to elicit values, priorities, and preferred characteristics of protocols for proactive subcounty breast cancer mapping. Upon formulating a protocol, we applied it to 9 years of data (2000-2008) describing invasive breast cancer in California for evaluation by the Expert Advisory Group.


RESULTS
Maps with subcounty resolution were seen to provide important information with a wide range of applications. Priorities included the avoidance of false-positive findings, scientific credibility, and the provision of information elucidating social and environmental characteristics. A protocol using Kulldorff's Scan Statistic along with postanalytic steps for refining results was elaborated; when applied to the data, 4 discrete regions with elevated rates of invasive breast cancer were identified and described.


CONCLUSIONS
Expert Advisory Group priorities were readily translatable into a scientifically rigorous protocol that protected confidentiality and avoided statistically unstable rate estimates. The resulting maps enabled participants to visualize geographically defined populations falling within and crossing county boundaries. These findings support the enactment of policies for the routine and proactive analysis of breast cancer surveillance data to provide subcounty information.
Public Health Institute, Richmond, CA 94804, USA. eric.roberts@phi.org
Eric M
EM
Roberts
Bahar
B
Kumar
Natalie
N
Collins
Liang
L
Guo
Galatea
G
King
Michelle
M
Wong
Janice
J
Barlow
Joyce
J
Bichler
Linda
L
Cady
Connie
C
Engel
Debbie
D
Garrett
Marie
M
Harrison
Adriana
A
Morieko
Neena
N
Murgai
Sora Park
SP
Tanjasiri
Karen
K
Pierce
D026683:Advisory Committees; D001943:Breast Neoplasms / Q000453:epidemiology*; D002140:California / Q000453:epidemiology; D005260:Female; D062305:Geographic Mapping; D019983:Guideline Adherence; D006284:Health Plan Implementation; D006801:Humans; D015994:Incidence; D012042:Registries / Q000706:statistics & numerical data*