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Markers for Nodal Metastasis in Head and Neck Squamous Cell Cancer
Robert P. Takes, MD, PhD;
Robert J. Baatenburg de Jong, MD, PhD;
Martijn J. R. C. Alles, MD;
Cees A. Meeuwis, MD, PhD;
Henri A. M. Marres, MD, PhD;
Paul P. M. Knegt, MD, PhD;
Guy Brutel de la Riviere, MD, PhD;
Peter C. M. de Wilde, MD, PhD;
Wolter J. Mooi, MD, PhD;
Jo Hermans, PhD;
J. Han J. M. van Krieken, MD, PhD
Arch Otolaryngol Head Neck Surg. 2002;128:512-518.
ABSTRACT
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Objective To identify markers that are relevant as predictors of lymph node metastasis
in head and neck squamous cell cancer.
Design Expression of p53, Rb, cyclin D1, E-cadherin, and epithelial cell adhesion
molecule was examined using immunohistochemical analysis and traditional histological
parameters, and the correlation of these markers with the histologically verified
presence of regional metastases was determined.
Subjects The study sample comprised 121 patients with head and neck squamous
cell cancer from whom paraffin-embedded material of primary tumors was used.
Results Lymph node metastasis was correlated with the loss of expression of
Rb (P = .04) and marginally correlated with the loss
of expression of E-cadherin (P = .06). If the results
are broken down to subsites, loss of E-cadherin expression in oral cancer
(P = .04) and absence of eosinophilic infiltration
in laryngeal cancer (P = .003) correlated with nodal
metastasis. None of the other markers correlated. A combination of relevant
parameters did not result in a much stronger correlation.
Conclusions The expression of the investigated genetic markers and histopathological
features of primary tumors can supply limited information on the metastatic
behavior of tumors. Although the use of markers for regional metastasis would
be a welcome additional tool, these results do not warrant the use of these
parameters for clinical decision making concerning the treatment of the neck
in patients with head and neck squamous cell cancer.
INTRODUCTION
REGIONAL METASTASIS is an important factor in the prognosis and choice
of treatment of patients with head and neck squamous cell cancer (HNSCC).
The presence of nodal metastasis will significantly affect the survival of
the patient.1 In most patients with HNSCC,
a decision of whether to treat the lymph nodes of the neck has to be made.
Diagnostic means to assess the lymph node status of the neck are not reliable.
Owing to high false-negative rates, many patients with HNSCC will undergo
elective neck treatment. For a considerable number of these patients, this
means an unnecessary treatment for their neck with significant morbidity.2-4
The techniques to assess the nodal status of the neck have improved
in recent years. However, even ultrasound with ultrasound-guided fine-needle
aspiration biopsy (presently, the most accurate technique to detect lymph
node metastases) identifies clinically occult metastases with a sensitivity
of no more than 48% to 76%.5-6
Moreover, because of the limited specificity in the range of 70% to 85%7-9 of techniques such as
computed tomography and magnetic resonance imaging, patients may receive unnecessary
neck treatment based on false-positive findings. The limitation of all these
techniques is that by palpation or imaging techniques small metastatic deposits
will still be undetected, and uncertainty about the true lymph node status
of the neck will remain.
The process of metastasis is a result of changes in properties of cells
and of interaction between tumor cells and surrounding cells and structures.
To metastasize, cells proliferate, lose contact with neighboring cells, migrate
through the interstitial matrix, invade blood and lymph vessels, and grow
out again in lymph nodes or distant organs. The metastatic cells, therefore,
have to possess several properties to perform all these actions.10
These tumor cell properties will be based on changes in genes and their products.
Based on the assumption that metastasis is mainly determined by properties
of the primary tumor and its interaction with the surrounding structures,10 it is worthwhile to explore the possibility of predicting
the presence of metastases based on features of the primary tumor. In that
case it would be possible to obtain additional information concerning the
chance of metastasis, irrespective of the size of the metastases, by studying
features of the primary tumors themselves. In an earlier pilot study, it appeared
to be feasible to assess the chance on metastasis in laryngeal cancers using
a panel of relevant factors.11 If biological
markers prove to be reliable diagnostic tools, they may reduce the need for
elective neck treatment.12
METHODS
Expression of p53, Rb, cyclin D1, E-cadherin, and epithelial cell adhesion
molecule (Ep-CAM) and histological parameters (differentiation grade, growth
pattern, tumor-associated eosinophilic infiltration, and inflammatory reaction)
were examined in 121 primary tumors in patients with HNSCC. All patients were
previously untreated. The correlation of these markers and parameters with
the histologically verified presence of regional metastases was determined.
From the files of the departments of pathology of all participating
institutions, 121 tissue blocks were retrieved from resection specimens of
laryngeal, pharyngeal, and oral carcinomas, which were resected en bloc with
the regional lymph nodes between the years 1990 and 1995. A portion of the
patients had been enrolled in a multicenter study on the value of ultrasound
with ultrasound-guided fine-needle aspiration biopsy in the assessment of
the nodal status of the neck in patients with HNSCC.13
The population characteristics (ie, age; sex; site; and T, N, and pN stage)
are summarized in Table 1. The
proteins were analyzed using immunohistochemistry as previously described.11 The antibodies used are summarized in Table 2.
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Table 1. Population Characteristics of 121 Patients With Head and Neck
Squamous Cell Cancer*
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Table 2. Panel of Antibodies Used
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Most proteins (except cyclin D1 and E-cadherin) were studied using the
3-step indirect method. In brief, 5-µm sections of paraffin-embedded
tissue were dewaxed in xylol for 15 minutes and rehydrated with alcohol. Endogenous
peroxidase was blocked with 0.3% hydrogen peroxidase. Subsequently, the sections
were pretreated for antigen retrieval as follows: for p53, Rb, and E-cadherin,
the sections were first boiled in citrate buffer (pH 6.0) for 10 minutes and
cooled down for at least 2 hours; for Ep-CAM, the sections were pretreated
with trypsin solution (0.1% trypsin with 0.1% calcium chloride) (pH 7.4) at
37°C for 20 minutes. After washing with phosphate-buffered saline (PBS),
the primary antibody was applied for overnight incubation with 1% bovine serum
albumin in PBS. After washing with PBS, the sections were incubated with the
secondary antibody. For monoclonals, rabbit antimouse IgG (DakoP161, Dako
Corp, Carpinteria, Calif) was applied for 45 minutes, then washed in PBS,
and finally incubated with the tertiary antibody, swine antirabbit IgG (DakoP217,
Dako Corp) for 45 minutes. For polyclonals, no tertiary antibody was used.
For cyclin D1 and E-cadherin, the avidin-biotin-peroxidase complex staining
method was applied.
After the final washing with PBS, staining was performed by means of
3-amino-9-ethylcarbazole in dimethylformamide with hydrogen peroxide followed
by counterstaining with Mayer hematoxylin for 30 seconds. The sections were
dyed blue in tap water and mounted with glycerin gelatin.
All cases were stained simultaneously for each protein with appropriate
specimens as a positive and negative control. As a positive control, tumor
specimens were used that showed positive results in former studies. As a negative
control, the sections were processed without the primary antibody. Moreover,
nonneoplastic cells in the section served as an internal negative control.
Two observers (R.P.T. and J.H.J.M.v.K.) evaluated the staining results.
Differences in scoring were discussed during examination at a multiheaded
microscope until agreement was reached. For each antibody, scoring categories
were made. For convenience in reporting, before statistical analysis a dichotomy
(positive vs negative) was made as previously described.14
The cutoff points were based on the distribution of staining results in the
different scoring categories. For p53 and Rb, the cutoff point was 0% to 15%
vs greater than 15%; for cyclin D1, 0% to 5% vs greater than 5%; and for E-cadherin
and Ep-CAM, cases with no staining were compared with cases showing any staining.
Some cases were not able to be evaluated owing to the absence of sufficient
tumor in the specimens or inconclusive staining results. Traditional histological
parameters were scored as described before.11
The correlation of the investigated parameters with the histologically
verified presence of lymph node metastasis was tested using the  2 test or Fisher exact test. For all analyses, P<.05
was considered significant.
RESULTS
The markers and histological parameters were examined in 121 cases of
HNSCC and related to the development of nodal metastasis. The expression rates
of the investigated markers are summarized in Table 3.
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Table 3. Relation of Investigated Parameters With Lymph Node Metastasis
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Lymph node metastases was correlated with the loss of expression of
Rb (P = .04) and marginally correlated with the loss
of expression of E-cadherin (P = .06). None of the
other markers or histological features showed a correlation with nodal metastasis
(Table 3). T stage (P = .26, data not shown) and T1 and T2 vs T3 and T4 (P = .83, data not shown) did not correlate with metastasis either.
The choice of cutoff points to separate negative from positive results
usually lacks a fundamental basis and is often rather arbitrary. To see if
the choice of cutoff points in the scoring categories would influence the
results, several cutoff points for considering results positive or negative
were examined for each marker. Most of the cutoff points used in an earlier
study14 also resulted in the most significant
correlations (15% for Rb and 0% vs greater than 0% for E-cadherin). For expression
of p53 and cyclin D1, no correlation with lymph node metastasis was found
using any of the alternative cutoff points. For p53, the best alternative
cutoff point of 50% did not result in a significant correlation (P = .67) and neither did the cutoff point of 75% for cyclin D1 (P = .48). For Ep-CAM, only 2 scoring categories were made,
so no alternative cutoff points could be explored.
To investigate if a combination of parameters would be more informative,
the results of the markers that showed some relation with nodal metastasis
were combined. The combination of Rb and E-cadherin did not result in a better
correlation with nodal metastasis (P = .15, data
not shown) and neither did the addition of inflammatory reaction (P = .37, data not shown).
If the correlation of the investigated parameters with nodal metastasis
is examined for the 3 subsites of the head and neck (ie, larynx, pharynx,
and oral cavity), the results are different compared with the entire population
(Table 4). It should be noted,
however, that the number of cases is limited. For the larynx, absence of eosinophilic
infiltration correlated with the presence of nodal metastasis (P = .003). For pharyngeal cancers, no significant correlations were
found, and for oral cancers, E-cadherin expression correlated with nodal metastasis
(P = .04). All tumors with loss of expression of
E-cadherin had lymph node metastases.
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Table 4. Relation of Investigated Parameters With Lymph Node Metastasis
for Each of the Subsites of the Head and Neck: Larynx, Pharynx, and Oral Cavity
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Markers for assessment of nodal metastasis are particularly useful in
the N0 neck. Table 5 summarizes
the results of the analysis performed in the subpopulation of 60 patients
with no palpable masses in the neck. In this population, the loss of expression
of Rb was marginally correlated with the presence of nodal metastases (P = .06). No relation between the other investigated parameters
and nodal metastasis was found. In the subpopulation of patients (n = 49)
with no detectable metastasis in the ultrasound-guided fine-needle aspiration
biopsy findings, no correlations between marker expression and the presence
of nodal metastasis could be established (Table 6).
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Table 5. Relation of Investigated Parameters With Lymph Node Metastasis
in the Clinically N0 Group
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Table 6. Relation of Investigated Parameters With Lymph Node Metastasis
in the Group With No Detectable Lymph Node Metastases Using Ultrasound-Guided
Fine-Needle Aspiration Biopsy
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COMMENT
In recent years, an increasing number of studies have focused on finding
parameters to assess the lymph node status of the neck in patients with HNSCC.
Diagnostic imaging techniques improve continuously but have the fundamental
limitation that the metastases need to have a minimal size of at least several
millimeters to be detected. Moreover, they have a low specificity if the imaging
is not combined with fine-needle aspiration biopsy.7-9
More recently, histological features and changes in gene expression of tumors
have been explored for predictors of nodal metastasis. In earlier studies,
the relation of individual markers with metastasis has only been studied in
the context of detecting clinicopathological correlations in general. Now,
studies are performed focussing on the issue of the management of the N0 neck.
The feasibility of assessing the chance on metastasis more reliably using
a set of tumor-related parameters is currently under investigation.11, 15
In the present study, we found a correlation with nodal metastasis for
the loss of expression of Rb and a near significant correlation for the loss
of expression of E-cadherin. Combining the results of these 2 markers did
not result in a better correlation with metastasis. If the correlation of
the investigated parameters with nodal metastasis is examined for the 3 subsites
of the head and neck, the results are different compared with those of the
entire population. For the larynx and pharynx, this may be due to the low
number of cases without metastasis because in this group the number of elective
neck dissections was low. Moreover, the number of cases per group is lower,
resulting in less statistically significant relations. The difference in results
between the subsites may also underline the possible difference in intrinsic
biological properties between tumors arising in the several subsites of the
head and neck.14 The results in the clinically
N0 group do not essentially differ from those of the entire group, except
for E-cadherin. Probably due to the lower number of cases, statistical significance
is not obtained for all parameters showing a correlation with metastasis in
the entire group.
The loss of Rb expression correlated positively with the presence of
nodal metastasis. In an earlier study of laryngeal carcinomas, however, we
found an inverse correlation.11 We do not have
a good explanation for this difference. It may be due to the smaller number
of cases in our previous study or a difference in population characteristics
(eg, some of the patients in the earlier study received prior radiotherapy,
and in the present study, more higher-stage tumors were included because all
patients underwent neck dissection). The expression of Rb has not been frequently
studied in HNSCC.16-17 However,
in 1 study a relation between the expression of Rb and nodal status has been
described.17
The other marker that nearly significantly correlated with the presence
of nodal metastasis in our study was E-cadherin. E-cadherin is an important
molecule in cell-cell adhesion, and changes in its expression may, together
with other factors, play a role in the process of metastasis.18
A relation between the loss of expression of E-cadherin and the development
of metastases has been described in several studies as reviewed by Jiang.19 Also in HNSCC, relations between the loss of E-cadherin
expression and the presence of nodal metastasis have been reported.20 Other studies, however, failed to find a statistically
significant relation between the loss of expression of E-cadherin in the primary
tumor and the occurrence of nodal metastases.21-23
For the other markers (ie, p53, cyclin D1, and Ep-CAM), no correlation with
the development of lymph node metastasis was found in the present study.
One of the most frequently studied markers in recent years is the tumor
suppressor gene p53. Point mutations of p53, leading
to nuclear accumulation of the protein, are among the most frequent genetic
alterations in HNSCC. Clinicopathological studies of alterations in p53 in
HNSCC show varying results as discussed in a review of Raybaud-Diogene et
al.24 Some authors did not find any correlation
of p53 expression with clinical parameters,25
metastasis,26 or survival.27-28
However, others found a correlation between nuclear p53 accumulation and survival,
although reports are contradictory: some found a correlation with worse survival
rates,29-30 and others, with better.31
Cyclin D1 is a potentially relevant prognostic marker and marker for
the development of metastasis. Cyclin D1 was first described as a candidate
oncogene in 1991 by Motokura et al32 as PRAD-1 and plays an important role in cell cycle regulation.
Overexpression of cyclin D1 may cause deregulation of the cell cycle and thus
contribute to tumorigenesis. Studies of HNSCC concerning amplification of
the chromosome 11q13 region, where the cyclin D1 and EMS-1 genes are harbored,
indicated a relation of this amplification with the development of nodal metastasis.11, 33-37
The relation between lymph node metastasis and the expression of cyclin D1
has not been studied frequently. In examining the expression of cyclin D1
with immunohistochemistry, Michalides et al38
found no correlation of cyclin D1 expression with N stage; however, other
authors did.36, 39 Therefore, although
amplification of 11q13 genes seems to be correlated with the presence of metastasis,
this correlation has not been definitively confirmed for the expression of
these genes.
The expression of Ep-CAM has not been studied frequently in HNSCC. Increased
expression of Ep-CAM appears to result in decreased cadherin-mediated cell-cell
adhesion and may lead to segregation of Ep-CAM positive cells from the parental
cell population in vitro.40 This phenomenon
may facilitate the development of metastases in vivo. Other in vitro and animal
studies, however, suggest that expression of the molecule reduces the metastatic
potential.41 In an earlier study, we found
a near significant relation between the loss of expression and the development
of nodal metastasis.11 However, in the present
study of a larger series of HNSCC, this relation could not be confirmed.
The studies on correlations of expression of markers with nodal metastasis
or other clinical parameters often show conflicting results, which may be
due to a number of factors. Besides differences in techniques and antibodies,
many of these factors are related to the heterogeneity of tumors in which
no tumor is exactly alike and no tumor consists of a population of identical
cells.42-43 Chromosomal aberrations
and protein expression are different in some parts of the tumor compared with
others, which is usually thought to be a result of clonal evolution. In tumor
progression, some cells of a clone may acquire additional or different chromosomal
alterations, resulting in a subclone with different properties. If this subclone
is a relatively small part of the primary tumor, the expression of an examined
marker in this tumor will probably be scored negative. However, this subpopulation
of tumor cells may still be responsible for a certain biological behavior
such as metastasis. Indeed, the expression of markers in the primary tumor
does not always match that of their metastases,44
which makes the choice of biologically relevant cutoff points arbitrary. What
percentage of cells showing expression should be considered a positive result
and what percentage a negative result? As a result, cutoff points are often
not the same among studies. Another consequence of the heterogeneity of tumors
is that biopsy material used for examination may not represent the entire
tumor.44
In several studies, histological features of the tumor were found to
correlate with survival and/or the development of lymph node metastases. Correlations
between the presence of an inflammatory reaction and the absence of lymph
node metastasis have been described by several authors.11, 45-46
In some studies, a relation of eosinophilic infiltration surrounding the tumor
and favorable prognosis has been described, but a relation with lymph node
metastasis was not found frequently.47-50
Other studies did not find any significant clinicopathological correlations.51 A relation between the development of lymph node
metastasis and grade of differentiation45, 52-53
or growth pattern45, 54-59
has also been described. Therefore, traditional histological parameters seem
to be able to provide useful information.
Because the process of tumor development and metastasis is complex,
it is unlikely that a single parameter will be able to predict the metastatic
behavior of a tumor. However, in our study the number of single parameters
showing a correlation with nodal metastasis was low, and a combination of
the most relevant parameters was not more predictive for nodal metastasis.
CONCLUSIONS
If more relevant parameters can be identified in the future, the combination
of the expression of markers and histopathological features of primary tumors
may be able to supply information on the metastatic behavior of tumors and
influence clinical decision making concerning the treatment of the neck in
patients with HNSCC. The investigated parameters in this study, however, did
not show correlations with nodal metastasis strong enough to be useful in
clinical practice. Moreover, the inconsistent results between studies in the
literature hamper the actual introduction of these markers for clinical purposes.
Uniform standards are required to make the results of studies comparable.
AUTHOR INFORMATION
Accepted for publication October 11, 2001.
This study was presented at the Fifth International Conference on Head
and Neck Cancer, San Francisco, Calif, July 31, 2000.
Corresponding author: Robert P. Takes, MD, PhD, Department of Otorhinolaryngology
and Head and Neck Surgery, University Medical Center Nijmegen, Greet Grooteplein
10, PO Box 9101, 6500 HB Nijmegen, the Netherlands (e-mail: r.takes{at}kno.azn.nl).
From the Departments of Otolaryngology–Head and Neck Surgery,
University Hospital, Leiden (Drs Takes, Baatenburg de Jong, and Alles), Daniël
den Hoed Cancer Center, Rotterdam (Dr Meeuwis), University Hospital, Nijmegen
(Dr Marres), and University Hospital, Rotterdam (Dr Knegt), the Netherlands;
the Departments of Pathology, Daniël den Hoed Cancer Center, Rotterdam
(Dr de la Riviere), University Hospital, Nijmegen (Dr de Wilde), and University
Hospital, Rotterdam (Dr Mooi), and University Hospital, Leiden (Dr van Krieken);
and the Department of Medical Statistics, University of Leiden (Dr Hermans).
REFERENCES
| |
1. Batsakis JG. Tumors of the Head and Neck. 2nd ed. Baltimore, Md: Williams & Wilkins; 1979.
2. Schuller DE, Reiches NA, Hamaker RC, et al. Analysis of disability resulting from treatment including radical neck
dissection or modified neck dissection. Head Neck Surg. 1983;6:551-558.
ISI
| PUBMED
3. Remmler D, Byers R, Scheetz J, et al. A prospective study of shoulder disability resulting from radical and
modified neck dissections. Head Neck Surg. 1986;8:280-286.
ISI
| PUBMED
4. Patten C, Hillel AD. The 11th nerve syndrome: accessory nerve palsy or adhesive capsulitis? Arch Otolaryngol Head Neck Surg. 1993;119:215-220.
FULL TEXT
|
ISI
| PUBMED
5. van den Brekel MW, Castelijns JA, Stel HV, et al. Occult metastatic neck disease: detection with US and US-guided fine-needle
aspiration cytology. Radiology. 1991;180:457-461.
FREE FULL TEXT
6. Takes RP, Righi P, Meeuwis CA, Manni JJ, Knegt P, Marres HAM. The value of ultrasound with ultrasound-guided fine-needle aspiration
biopsy compared to computed tomography in the detection of regional metastases
in the clinically negative neck. Int J Radiat Oncol Biol Phys. 1998;40:1027-1032.
FULL TEXT
|
ISI
| PUBMED
7. Close LG, Merkel M, Vuitch MF, Reisch J, Schaefer SD. Computed tomographic evaluation of regional lymph node involvement
in cancer of the oral cavity and oropharynx. Head Neck. 1989;11:309-317.
ISI
| PUBMED
8. van den Brekel MW, Castelijns JA, Stel HV, Golding RP, Meyer CJ, Snow GB. Modern imaging techniques and ultrasound-guided aspiration cytology
for the assessment of neck node metastases: a prospective comparative study. Eur Arch Otorhinolaryngol. 1993;250:11-17.
PUBMED
9. van den Brekel MW, Castelijns JA, Croll GA, et al. Magnetic resonance imaging vs palpation of cervical lymph node metastasis. Arch Otolaryngol Head Neck Surg. 1991;117:663-673.
PUBMED
10. Liotta LA. Cancer cell invasion and metastasis. Sci Am. 1992;266:54-63.
ISI
| PUBMED
11. Takes RP, Baatenburg de Jong RJ, Schuuring E, et al. Markers for assessment of nodal metastasis in laryngeal carcinoma. Arch Otolaryngol Head Neck Surg. 1997;123:412-419.
FULL TEXT
|
ISI
| PUBMED
12. Baatenburg de Jong RJ, Knegt P, Verwoerd CD. Reduction of the number of neck treatments in patients with head and
neck cancer. Cancer. 1993;71:2312-2318.
FULL TEXT
|
ISI
| PUBMED
13. Takes RP, Knegt P, Manni JJ, et al. Regional metastasis in head and neck squamous cell carcinoma: revised
value of US with US-guided FNAB. Radiology. 1996;198:819-823.
FREE FULL TEXT
14. Takes RP, Baatenburg de Jong RJ, Schuuring E, Litvinov SV, Hermans J, van Krieken JHJM. Differences in expression of oncogenes and tumor suppressor genes in
different sites of head and neck squamous cell cancer. Anticancer Res. 1998;18:4793-4800.
ISI
| PUBMED
15. Byers RM, el-Naggar AK, Lee Y-Y, et al. Can we detect or predict the presence of occult nodal metastases in
patients with squamous carcinoma of the oral tongue? Head Neck. 1998;20:138-144.
FULL TEXT
|
ISI
| PUBMED
16. Pavelic ZP, Lasmar M, Pavelic L, et al. Absence of retinoblastoma gene product in human primary oral cavity
carcinomas. Eur J Cancer B Oral Oncol. 1996;32B:347-351.
17. Andl T, Kahn T, Pfuhl A, et al. Etiological involvement of oncogenic human papillomavirus in tonsillar
squamous cell carcinomas lacking retinoblastoma cell cycle control. Cancer Res. 1998;58:5-13.
FREE FULL TEXT
18. Takeichi M. Cadherins in cancer: implications for invasion and metastasis. Curr Opin Cell Biol. 1993;5:806-811.
FULL TEXT
| PUBMED
19. Jiang WG. E-cadherin and its associated protein catenins, cancer invasion and
metastasis. Br J Surg. 1996;83:437-446.
ISI
| PUBMED
20. Schipper JH, Unger A, Jahnke K. E-cadherin as a functional marker of the differentiation and invasiveness
of squamous cell carcinoma of the head and neck. Clin Otolaryngol. 1994;19:381-384.
ISI
| PUBMED
21. Bowie GL, Caslin AW, Roland NJ, Field JK, Jones AS, Kinsella AR. Expression of the cell-cell adhesion molecule E-cadherin in squamous
cell carcinoma of the head and neck. Clin Otolaryngol. 1993;18:196-201.
ISI
| PUBMED
22. Mattijssen V, Peters HM, Schalkwijk L, et al. E-cadherin expression in head and neck squamous-cell carcinoma is associated
with clinical outcome. Int J Cancer. 1993;55:580-585.
ISI
| PUBMED
23. Andrews NA, Jones AS, Helliwell TR, Kinsella AR. Expression of the E-cadherin-catenin adhesion complex in primary squamous
cell carcinomas of the head and neck and their nodal metastases. Br J Cancer. 1997;75:1474-1480.
ISI
| PUBMED
24. Raybaud-Diogene H, Tetu B, Morency R, Fortin A, Monteil RA. p53 Overexpression in head and neck squamous cell carcinoma: review
of the literature. Eur J Cancer B Oral Oncol. 1996;32B:143-149.
25. Ma L, Ronai A, Riede UN, Kohler G. Clinical implication of screening p53 gene mutations in head and neck
squamous cell carcinomas. J Cancer Res Clin Oncol. 1998;124:389-396.
FULL TEXT
|
ISI
| PUBMED
26. Pruneri G, Pignataro L, Carboni N, et al. Clinical relevance of p53 and bcl-2 protein over-expression in laryngeal
squamous-cell carcinoma. Int J Cancer. 1998;79:263-268.
FULL TEXT
|
ISI
| PUBMED
27. Awwad S, Jaros E, Somes J, Lunec J. p53 Overexpression in head and neck carcinoma and radiotherapy results. Int J Radiat Oncol Biol Phys. 1996;34:323-332.
FULL TEXT
|
ISI
| PUBMED
28. Ahomadegbe JC, Barrois M, Fogel S, et al. High incidence of p53 alterations (mutation, deletion, overexpression)
in head and neck primary tumors and metastases; absence of correlation with
clinical outcome: frequent protein overexpression in normal epithelium and
in early non-invasive lesions. Oncogene. 1995;10:1217-1227.
ISI
| PUBMED
29. Girod SC, Cesarz D, Fischer U, Krueger GR. Detection of p53 and MDM2 protein expression in head and neck carcinogenesis. Anticancer Res. 1995;15:1453-1457.
ISI
| PUBMED
30. Spafford MF, Koeppe J, Pan Z, Archer PG, Meyers AD, Franklin WA. Correlation of tumor markers p53, bcl-2, CD34, CD44H, CD44v6, and Ki-67
with survival and metastasis in laryngeal squamous cell carcinoma. Arch Otolaryngol Head Neck Surg. 1996;122:627-632.
ISI
| PUBMED
31. Hirvikoski P, Kumpulainen E, Virtaniemi J, et al. p53 Expression and cell proliferation as prognostic factors in laryngeal
squamous cell carcinoma. J Clin Oncol. 1997;15:3111-3120.
ABSTRACT
32. Motokura T, Bloom T, Kim HG, et al. A novel cyclin encoded by a bcl1-linked candidate oncogene. Nature. 1991;350:512-515.
FULL TEXT
| PUBMED
33. Muller D, Millon R, Lidereau R, et al. Frequent amplification of 11q13 DNA markers is associated with lymph
node involvement in human head and neck squamous cell carcinomas. Eur J Cancer B Oral Oncol. 1994;30B:113-120.
34. Jares P, Fernández PL, Campo E, et al. PRAD-1/cyclin D1 gene amplification correlates with messenger RNA overexpression
and tumor progression in human laryngeal carcinomas. Cancer Res. 1994;54:4813-4817.
FREE FULL TEXT
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