Summary: Lung carcinoma is subdivided into small cell carcinoma and non-small cell carcinoma (NSCLC). NSCLC is heterogeneous group of carcinomas and accounts for 70–80% of lung cancer. NSCLC is further divided into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with non-small cell lung cancer (NSCLC). These mutations involve exons 18, 19, 20 and 21. Patients harboring these mutations in their tumors show good response to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this manuscript is to provide an overview of EGFR mutations in NSCLC as well as to briefly discuss sample requirements and testing guidelines for EGFR mutation. Keywords: Adenocarcinoma of lung, EGFR mutation, Targeted therap

Fouad Al Dayel

Journal of Infection and Public Health

SummaryLung carcinoma is subdivided into small cell carcinoma and non-small cell carcinoma (NSCLC). NSCLC is heterogeneous group of carcinomas and accounts for 70–80% of lung cancer. NSCLC is further divided into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.Activating somatic mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR) have recently been characterized in a subset of patients with non-small cell lung cancer (NSCLC). These mutations involve exons 18, 19, 20 and 21. Patients harboring these mutations in their tumors show good response to EGFR tyrosine kinase inhibitors (EGFR-TKIs). The aim of this manuscript is to provide an overview of EGFR mutations in NSCLC as well as to briefly discuss sample requirements and testing guidelines for EGFR mutation

Al Dayel, Fouad

Elsevier - Publisher Connector 

JE
c
F
D
R
R
I
A
[
n
p
c
n
a
a
A
1
hournal of Infection and Public Health (2012) 5, S31—S34
GFR  mutation  testing  in  non-small  cell  lung
ancer  (NSCLC)
ouad  Al  Dayel1
epartment  of  Pathology  and  Laboratory  Medicine,  King  Faisal  Specialist  Hospital  and  Research  Centre,
iyadh, Saudi  Arabia
eceived  22  January  2012;  received  in  revised  form  22  January  2012;  accepted  20  September  2012
KEYWORDS
Adenocarcinoma of lung;
EGFR mutation;
Targeted therapy
Summary  Lung  carcinoma  is  subdivided  into  small  cell  carcinoma  and  non-small
cell  carcinoma  (NSCLC).  NSCLC  is  heterogeneous  group  of  carcinomas  and  accounts
for  70—80%  of  lung  cancer.  NSCLC  is  further  divided  into  adenocarcinoma,  squamous
cell  carcinoma,  and  large  cell  carcinoma.
Activating  somatic  mutations  of  the  tyrosine  kinase  domain  of  epidermal  growth
factor  receptor  (EGFR)  have  recently  been  characterized  in  a  subset  of  patients
with  non-small  cell  lung  cancer  (NSCLC).  These  mutations  involve  exons  18,  19,
20  and  21.  Patients  harboring  these  mutations  in  their  tumors  show  good  response
to  EGFR  tyrosine  kinase  inhibitors  (EGFR-TKIs).  The  aim  of  this  manuscript  is  to
provide  an  overview  of  EGFR  mutations  in  NSCLC  as  well  as  to  brieﬂy  discuss  sample
requirements  and  testing  guidelines  for  EGFR  mutation.
©  2012  Published  by  Elsevier  Limited  on  behalf  of  King  Saud  Bin  Abdulaziz  University
for  Health  Sciences.  All  rights  reserved.
d
c
a
o
c
bntroduction
s  per  current  World  Health  Organization  (WHO)
1], lung  carcinoma  is  subdivided  into  small  cell  and
on-small  cell  carcinoma  (NSCLC).  The  latter  com-
romise 70—80%  of  lung  carcinoma.  Although  NSCLC
onsists  of  squamous  cell  carcinoma,  adenocarci-
oma and  large  cell  carcinoma,  it  was  considered
s one  group  mainly  because  of  lack  of  speciﬁc  ther-
py for  various  histologic  subtypes.  Nowadays  the
E-mail address: dayelf@kfshrc.edu.sa
1 On behalf of the Lung Cancer Guidelines Committee. See
ppendix A.
r
c
e
c
i
o
876-0341/$  —  see  front  matter  ©  2012  Published  by  Elsevier  Limited  on  behalf  of
ttp://dx.doi.org/10.1016/j.jiph.2012.09.008istinction  between  adenocarcinoma  and  squamous
ell carcinoma  is  extremely  important  due  to  avail-
bility of  therapy.
There is  increasing  interest  in  adenocarcinoma
f lung  for  various  reasons.  One  reason  is adenocar-
inoma  incidence  is  increasing  (now  considered  to
e the  most  predominant  histologic  subtype).  Other
eason is the  potential  uses  of  targeted  therapy  in
ases showing  EGFR  mutations.
Since 1980s,  many  studies  showed  EGFR  over-
xpression in  lung  carcinoma  particularly  squamous
ell carcinoma  using  various  techniques  including
mmunohistochemistry.  However,  the  signiﬁcance
f these  over-expressions  as  prognostic  marker
 King  Saud  Bin  Abdulaziz  University  for  Health  Sciences.  All  rights  reserved.
p
a
b
m
E
T
d
w
f
p
c
d
4
p
e
a
b
M
D
a
i
e
t
t
t
(
T
M
i
p
E
t
f
i
a
o
t
t
SS32  
continued  to  be  controversial.  Clinical  trials
revealed variability  in  response  to  tyrosine  kinase
inhibitor,  with  higher  response  seen  in  Japanese
patients than  European  patients  (27.5%  vs.  10.4%).
In USA,  partial  response  was  noticed  in  women,  in
non-smoker  and  patient  with  adenocarcinoma.  The
breakthrough  took  place  in  2004,  Lynch  et  al.  [2]
reported  that  activating  mutations  of  EGFR  gene
kinase  domain  resulted  in  responsiveness  to  tyro-
sine kinase  inhibitors  (TKIs)  in  patients  with  lung
adenocarcinoma.  Simultaneously  two  independent
groups reported  similar  results  [3,4].  Up  to  20%  of
NSCLC shows  EGFR  mutation  and  up  to  80%  of  these
patients  respond  to  TKIs  (only  10%  of  EGFR  muta-
tion negative  cases  respond  to  TKIs).  However,  most
of these  patients  will  develop  resistance  to  treat-
ment within  one  year  [5].  Secondary  resistance  is
either due  to  second  EGFR  mutation  T790M,  or  MET
ampliﬁcation.
The most  frequent  mutations  in  EGFR  are  exon
19 deletions  and  exon  21  point  mutation:  L858R
(replacement  of  leucine  at  position  858  in  the  pro-
tein with  arginine).  Mutations  detection  start  with
extracting  good  quality  DNA  followed  by  ampliﬁca-
tions of  exon  18—21  of  EGFR  tyrosine  kinase  domain
then bidirectional  sequencing.
The recommendation  from  International  Asso-
ciation  for  the  Study  of  Lung  Cancer  (IASLC),
American Thoracic  Society  (ATS)  and  European
Respiratory Society  (ERS)  [6]  is  to  test  for  EGFR
mutation in  all  cases  of  lung  adenocarcinoma,  pos-
sible adenocarcinoma  and  NSCLC—–not  otherwise
speciﬁed. If  EGFR  testing  is  negative,  Alkfusion  Test
should be  performed.  It is  optional  to  proceed  to
KRAS mutation  testing  (codon  12  and  13).  Acti-
vating  mutations  in  KRAS  gene  were  shown  to  be
of negative  predictive  value  to  TKIs.  Also,  KRAS
mutations  correlate  with  smoking  history  and  poor
prognosis.
EGFR mutations
EGFR  is  a  member  of  receptor  tyrosine  kinase
family and  a  major  factor  in  regulating  cellular  pro-
liferation,  invasion,  metastasis,  angiogenesis  and
inhibition of  apoptosis.  EGFR  signals  activate  at
least two  parallel  intracellular  pathways  [7].  One  of
these pathways,  is  the  MAP  kinase  pathway  (MAPK)
that regulates  G1  checkpoint  in  the  cell  cycle  and
control  cellular  proliferation  [8].  Once  EGFR  is  acti-
vated, the  MAPK  pathway  transmits  the  signal  to
the nucleus  via  the  active  forms  of  RAS,  RAF  and
MEK genes  [7,9].  The  RAS  proto-oncogene  consists
of H-ras,  K-ras  and  N-ras  [10],  located  in  the  inner
A
t
dF.  Al  Dayel
lasma  membrane  layer  and  present  in  either  the
ctive form  (GTP  bound)  or  the  inactive  form  (GDP
ound)  [11].
Mutant  EGFR  binds  ATP  less  tightly  and  binds  TKIs
ore tightly  than  wild  type  EGFR.
GFR testing
he  sample  available  is  usually  parafﬁn  embed-
ed tissue.  Preferably  primary  tumor  tissue  is  used,
hen this  is  not  available  one  may  consider  sample
rom metastatic  tissue.  Ideally,  the  tissue  sam-
le should  contain  at least  50%  of  viable  tumor
ells. Methods  with  higher  detection  sensitivity  can
etect mutation  with  lower  tumor  content  levels.
—10 m  sections  of  non-baked  unstained  slides
repared from  parafﬁn  block  and  one  H&E  refer-
nce slide  to  mark  the  area  of  interest.  The  tumor
rea of  interest  selected  by  the  pathologist  should
e a minimum  of  2  mm  ×  2  mm.
utation detection
etection  of  mutation  can  be  performed  using
 variety  of  mutation  platforms,  direct  sequenc-
ng is  widely  used  (amplify  and  sequence  EGFR
xons 18—21).  Other  methods  includes  real-
ime-PCR (ampliﬁcation  refractory  mutation  sys-
em), high  resolution  melting  analysis,  and  dena-
uring high  performance  liquid  chromatography
DHPLS).
esting facility
utation  analysis  testing  should  be  performed
n accredited,  quality  assured  facility  partici-
ating in  external  proﬁciency  testing  schemes.
GFR testing  should  be  validated  before  repor-
ing the  test  results.  Requirements  for  validation
or molecular  testing  are  both  analytical  and  clin-
cal. There  are  published  guidelines  for  validating
nd reporting  molecular  testing  [12].  The  College
f American  Pathologists  developed  recommenda-
ions for  testing,  validating  and  reporting  molecular
esting  [13].
ummarydenocarcinoma  is  the  most  common  histologic
ype of  NSCLC.  Treatment  decisions  of  NSCLC  are
ependent  on  two  important  factors.  The  ﬁrst  one
Ei
a
t
o
e
t
b
r
h
p
c
r
t
[
A
C
R
[
[
[GFR  mutation  testing  in  NSCLC  
s  accurate  histologic  classiﬁcation  using  H&E  stain
s well  as  several  immunohistochemical  stains  par-
icularly in  poorly  differentiated  carcinoma.  The
ther factor  is  testing  the  tumor  tissue  for  the  pres-
nce or  absence  of  speciﬁc  mutations  for  targeted
herapy. Since  most  of  the  tissue  specimens  are
iopsy  specimen,  the  pathologists  play  important
ole in  managing  the  tissue  carefully  for  immuno-
istochemical studies,  molecular  testing  and  for
ossible  research.
Utilizing  the  2011  IASLC/ATS/ERS  proposal  for
lassiﬁcation  of  lung  adenocarcinoma  is  highly
ecommended.  In  this  classiﬁcation,  histologic  sub-
ypes are  correlated  well  with  EGFR  mutations
14].
Funding: No  funding  sources.
Competing  interests: None  declared.
Ethical approval: Not  required.
ppendix A. Lung Cancer Guidelines
ommittee Members
Dr.  Abdul  Rahman  Jazieh,  King  Saud  bin  Abdulaziz
University for  Health  Sciences,  Riyadh,  Saudi  Ara-
bia.
Dr. Abdulrahman  Al  Hadab,  King  Saud  bin  Abdu-
laziz University  for  Health  Sciences,  Riyadh,  Saudi
Arabia.
Dr. Adnan  Hebshi,  King  Faisal  Specialist  Hospital  &
Research Center,  Riyadh,  Saudi  Arabia.
Dr.  Ahmed  Abdulwarith,  King  Fahad  Specialist  Hos-
pital, Dammam,  Saudi  Arabia.
Dr. Ahmed  Bamousa,  Riyadh  Military  Hospital,
Riyadh, Saudi  Arabia.
Dr.  Ahmed  Saadeddin,  Riyadh  Military  Hospital,
Riyadh, Saudi  Arabia.
Dr.  Ashwaq  Al  Olayan,  King  Saud  bin  Abdulaziz
University for  Health  Sciences,  Riyadh,  Saudi
Arabia.
Dr. Azzam  Khankan,  King  Saud  bin  Abdulaziz  Uni-
versity for  Health  Sciences,  Saudi  Arabia.
Dr. Foad  Al Dayel,  King  Faisal  Specialist  Hospital  &
Research Center,  Riyadh,  Saudi  Arabia.
Dr.  Hamed  Al  Husaini,  King  Faisal  Specialist  Hospi-
tal &  Research  Center,  Riyadh,  Saudi  Arabia.
Dr. Hamdan  Al  Jahdali,  King  Saud  bin  Abdulaziz
University for  Health  Sciences,  Riyadh,  Saudi  Ara-
bia.
Dr. Hana  Bameﬂeh,  King  Saud  bin  Abdulaziz  Uni-
versity for  Health  Sciences,  Riyadh,  Saudi  Arabia.
Dr. Khalid  Al  Kattan,  Al  Faisal  University,  Riyadh,
Saudi  Arabia.
Dr. Loutﬁ,  Shukri,  King  Saud  bin  Abdulaziz  Univer-
sity for  Health  Sciences,  Riyadh,  Saudi  Arabia.
[S33
Dr.  M.  Hasan  Rajab,  Al  Faisal  University,  Riyadh,
Saudi Arabia.
Dr. Sara  Al  Ghanim,  King  Saud  bin  Abdulaziz
University for  Health  Sciences,  Riyadh,  Saudi
Arabia.
Dr. Turki  Al  Fayae,  King  Abdulaziz  Medical  City,
Princess  Noorah  Oncology  Center,  Jeddah,  Saudi
Arabia.
Dr. Yasir  Bahadur,  King  Faisal  Specialist  Hospital  &
Research Center,  Jeddah,  Saudi  Arabia.
eferences
[1] Travis WD, Bramvilla E, Muller-Hermelink HK, Harris CC.
Pathology and genetics of tumours of the lung, pleura, thy-
mus and heart. World Health Organization Classiﬁcation
(WHO) of Tumours; 2004.
[2] Lynch TJ, Bell DW, Sordella R, Gurubhagavatula S, Okimoto
RA, Brannigan BW, et al. Activating mutations in the epi-
dermal growth factor receptor underlying responsiveness of
non-small-cell lung cancer to geﬁtinib. New England Journal
of Medicine 2004;350(21):2129—39.
[3] Paez JG, Jänne PA, Lee JC, Tracy S, Greulich H,
Gabriel S, et al. EGFR mutations in lung cancer: corre-
lation with clinical response to geﬁtinib therapy. Science
2004;304(5676):1497—500.
[4] Pao W, Miller V, Zakowski M, Doherty J, Politi K, Sarkaria
I, et al. EGF receptor gene mutations are common in lung
cancers from ‘‘never smokers’’ and are associated with sen-
sitivity of tumors to geﬁtinib and erlotinib. Proceedings of
the National Academy of Sciences of the United States of
America 2004;101(36):13306—11.
[5] Suda K, Onozato R, Yatabe Y, Mitsudomi T. EGFR
T790M mutation: a double role in lung cancer cell
survival?
[6] Travis WD,  Brambilla E, Noguchi M, Nicholson AG, Geisinger
KR, Yatabe Y, et al. International association for the study
of lung cancer/American thoracic society/European respi-
ratory society international multidisciplinary classiﬁcation
of lung adenocarcinoma. Journal of Thoracic Oncology
2011;6(February (2)):244—84.
[7] Yarden Y. The EGFR family and its ligands in human can-
cer. Signalling mechanisms and therapeutic opportunities.
European Journal of Cancer 2001;37(Suppl. 4):S3—8.
[8] Raponi M, Hans Winkler N, Dracopoli C. KRAS mutations
predict response to EGFR inhibitors. Current Opinion in
Pharmacology 2008;8(4):413—8.
[9] Ciardiello F, Tortora G. EGFR antagonists in can-
cer treatment. New England Journal of Medicine
2008;358(11):1160—74.
10] Lowy DR, Willumsen BM. Function and regulation of ras.
Annual Review of Biochemistry 1993;62:851—91.
11] Castagnola P, Giaretti W. Mutant KRAS, chromosomal
instability and prognosis in colorectal cancer. Biochim-
ica et Biophysica Acta (BBA) — Reviews on Cancer
2005;1756(2):115—25.
12] Lawrence J, Van Deerlin V, Gulley ML. Recommended
principles and practices for validating clinical molecu-
lar pathology tests. Archives of Pathology and Laboratory
Medicine 2009;133:743—55.
13] Gulley ML, Braziel RM, Halling KC, Hsi ED, Kant JA, Niki-
forova MN, et al. Clinical laboratory reports in molecular
S34  
pathology. Archives of Pathology and Laboratory Medicine
2007;131(6):852—63.
[14] Shim HS, Lee da H, Park EJ, Kim SH. Histopathologic
characteristics of lung adenocarcinomas with epithelial
growth factor receptor mutations in the International
Available  online  at  wwwF.  Al  Dayel
Association for the Study of Lung Cancer/American Thoracic
Society/European Respiratory Society Lung Adenocarci-
noma Classiﬁcation. Archives of Pathology and Laboratory
Medicine 2011;135(October):132.
.sciencedirect.com


EGFR mutation testing in non-small cell lung cancer (NSCLC) 

Directory of Open Access Journals

EGFR mutation testing in non-small cell lung cancer (NSCLC)

file:///data/core-remote/dit/data/elsevier/pdf/108/aHR0cDovL2FwaS5lbHNldmllci5jb20vY29udGVudC9hcnRpY2xlL3BpaS9zMTg3NjAzNDExMjAwMTE5MA==.pdf

EGFR mutation testing in non-small cell lung cancer (NSCLC)

Abstract

Similar works

Full text

Available Versions

Elsevier - Publisher Connector

Directory of Open Access Journals

Elsevier - Publisher Connector