Molecular changes detectable by in situ strategies

 Molecular changes detectable by in situ strategies 
immunohistochemistry and fluores cence in situ
hybridization ihc and fish are used to assess
levels molecules that might be therapeutically useful or elucidate
the biology of adenocarcinoma. ihc was applied in
adenocarcinoma to demonstrate that the expression of the
tyrosine kinase receptor, egfr, is less frequent and more
heterogeneous in a verydenocarcinoma than in squamous carcinoma.
25 egfr is strongly expressed in nonmucinous bac
(fig. 22. 14) and early anecdotal reports of dramatic responses
of tumors with nonmucinous bac morphology suggested
that expression levels of egfr would possibly predict response
to egfr blockade. though, giant subsequent ihc studies
have had mixed outcomes with a few studies indicating
no relationship between egfr level 341, 342 and effectiveness
of anti-egfr treatment however others suggesting improved response
in egfr positive non–small cell tumors regardless of
histology type. 343, 344 whatever the reason for this discrepancy,
it looks unlikely that egfr protein level by itself
are going to be a reliable predictive marker however might give added insight
into the biology of adenocarcinoma and, within the proper
context, may be of clinical use.
a mechanism for the overexpression of egfr was elucidated
when it absolutely was observed and subsequently confirmed that
high egfr gene copy range may be associated with overexpression
of egfr protein 345, 346 in nsclc as well as adenocarcinoma.
though, egfr protein overexpression might occur within the absence
of high gene copy range and protein level doesn't
so predict gene copy range. as reviewed elsewhere in
this volume, high egfr gene copy range has been found to
independently predict outcome in patients treated by egfr
blockade. 343, 344, 347, 348
several markers are reported to be connected to prognosis
in a verydenocarcinoma as well as carcinoembryonic antigen
(cea), 349 p53, 331 p27, 350 cyclooxygenase-2 (cox-2), 351 and
mib-1 index (ki67 labeling) (fig. 22. 13). 352 though, only
2 markers are considerably correlated with the prognosis of
early stage adenocarcinomas as well as bac and therefore their clinical
impact has been minor to date.
high-throughput gene expression arrays heterogeneity
in lung cancer histomorphology is currently increasingly
evident however the primary studies to spotlight the extent of this
hanging heterogeneity were molecular. gene expression array
analyses have demonstrated that adenocarcinomas may be
divided into many teams, a minimum of one among that has prognostic
importance. ninety six, 97, 207, 353–355 this prognostically important
cluster expresses markers that are previously
related to neuroendocrine differentiation and has a majorly
worse prognosis than different forms of pulmonary
adenocarcinoma.