Trial Information

Characterization of Molecular Subtypes of Breast Cancer and Their Relationships With Known Breast Cancer Risk Factors Among Chinese Women in Hong Kong - A Pilot Study

Background: Breast cancer incidence is increasing rapidly among many Asian populations
primarily due to the adaptation of a Westernized lifestyle. However, Asian women seem to
have a distinctive profile of breast cancer that differs from that seen in Western
populations, such as earlier age at onset, more advanced stage, and higher frequency of
ER-negative tumors. The disproportionally high rates among younger women were also seen
among U.S.-born Asian women, such as Chinese, Filipina, Indian, and Pakistani women. These
findings suggest that Asian breast cancer may have a distinct etiology that is not fully
explained by adapting a westernized lifestyle. Recent molecular studies have suggested that
breast cancers comprise several biologically and clinically distinct tumor subtypes.
Epidemiologic evidence suggests that associations with breast cancer risk factors may vary
by tumor subtype. However, most previous studies were conducted in Western populations;
large, population-based epidemiologic studies characterizing molecular subtypes of breast
cancer in Asian women are limited. In this study, we would like to characterize the
molecular profile of breast cancer among Chinese women in Hong Kong and associate the
molecular features with clinical and etiologic factors. An improved understanding of the
inter-relationships among age, breast cancer subtypes, and race/ethnicity is critical for
the development of targeted prevention and the best and most efficacious therapy.

Objectives: To assess the technical feasibility of 1) collecting fresh frozen tissues and
fixed tissue blocks from breast cancer cases in Hong Kong, and 2) conducting tumor profiling
analyses in the collected tissues.

Eligibility: Breast cancer cases who are participants in an ongoing breast cancer case
control study among Hong Kong women (Night shift and breast cancer: a case-control study
among Hong Kong women, led by Dr. Tse at Chinese University in Hong Kong) and who will
receive surgery at the North District Hospital, HK, in 2013.

Design: In this feasibility study, we plan to collect fresh frozen and fixed tissues (tumor
and adjacent normal) from ~100 breast cancer cases who have given consent to participate in
our breast tissue collection pilot study. DNA and RNA will be extracted from frozen tumors
and assessed for quality and yield. We will then conduct expression profiling analysis in a
subset of cases (N~10) to determine the quality of RNA in molecular profiling analysis. We
will also determine whether there are enough epithelial benign and tumor tissues for the
construction of tissue microarrays (TMAs). The results from this feasibility study will
inform our decision on whether or not to pursue a large scale study.