107tumor infiltrating lymphocytes. The tumor infiltrating lymphocytes
(TILs) were characterized by immunohistochemistry for CD3,
CD8, and FoxP3. They reported both high-grade total inflamma-
tion and high tumor infiltrating lymphocytes counts in the tumor
center, but not the tumor periphery and showed a beneficial prog-
nostic impact on esophageal adenocarcinoma. This may be a target
for novel therapeutic options and also serves as a prognostic indica-
tor in these carcinomas [ 9 ].
In some instances, TMA was used in the study of gene expres-
sion by in situ hybridization. In 2011, Thompson and colleagues
had constructed tissue microarray from 89 paraffin-embedded archi-
val specimens of esophageal adenocarcinomas for HER2 gene ampli-
fication by silver-enhanced in situ hybridization (SISH). HER2 gene
amplification was detected in 14 esophageal cancer specimens (16%),
and 92% of those with high-level HER2 amplification revealed posi-
tive HER2 protein overexpression. The 5-year survival rates were
57% for esophageal cancer patients with HER2 amplification when
compared with 32% without [ 10 ]. In the same year, Peters and col-
leagues showed that HER2 protein overexpression was observed in
12% (14 out of 116) of esophageal adenocarcinoma and 7% (1 out
of 15) of high-grade dysplasia. No HER2 amplification or overex-
pression was identified in Barrett esophagus with or without low-
grade dysplasia. In addition, all cases with HER2 protein
overexpression showed HER2 gene amplification [ 11 ].
In 2014, Geppert and colleagues examined four selected gene
loci using multicolor fluorescence in situ hybridization (FISH) on
TMA with 130 esophageal adenocarcinoma samples. Cell signal
number of the ERBB2 and ZNF217 loci showed the expression
was independent from tumor stage and differentiation grade of
esophageal adenocarcinoma. The prognostic value of multicolor
FISH-assays that applies to esophageal adenocarcinoma was supe-
rior to single markers [ 12 ].
In the recent years, researchers commonly use TMA to study a
large number of tissue samples instead of using the primary paraffin
blocks. Many research institutes had sets of tissue microarray from
patients with cancers in which the research staff could test many of
the markers in an effective way. Nevertheless, there are advantages
and disadvantages of TMA block when compared to paraffin blocks
(see Note 1). In this chapter, we will present the different types of
making TMA block.2 Materials
A blank paraffin block is a “recipient” for multiple tissue samples.
This is the final product of TMA. The most commonly used wax
for the “recipient” paraffin block is the commercially obtained
paraffin wax. In some companies, “recipient” paraffin blocks with2.1 “Recipient”
Paraffin Block
TMA and Esophageal Adenocarcinoma