Discussion
Our research found a significant correlation between lymph node
metastasis and the stage of the LSCC tumor (p=0.001). Redaelli et al.
studied the occult neck lymph node metastasis in LSCC patients and found
an incidence of 39.2% (6). This result was significantly correlated
with the stage of the tumor (P= 0.04). Yilmaz et al. study results are
also consistent with those of ours (7).
Our results showed that 91.6% of the subjects that had cervical lymph
node EGFR expression in their metastasis had a primary with moderate to
poor differentiation. It was also revealed that there is a strong
association between tumour grade of differentiation and the cervical
metastasis (p=0.001). Magnano et al. reported that the poorer the
differentiation was, the higher the possibility of cervical node
metastasis would be (8).
On the other side, we did not find evidence of statistical nor clinical
correlation between the age and the gender with the EGFR expression
state in the lymph nodes. Similarly, (Čelakovský, Kalfeřt, Smatanová, et
al., 2015) did not postulate age nor gender correlation with the
cervical metastasis in laryngeal cancer patients. (9)
Also, we did not reveal any statistically significant correlation
between the site of the primary and the cervical. This was in
consistency with the study results of Čelakovský et al. who did not
postulate a relation between tumor sub-site and EGFR expression in the
cervical metastasis (9). In contrast, Mayers & Allvi
reported that transglottic and supraglottic carcinoma cause early
cervical lymph node metastasis that they recommended lateral neck
dissection with the laryngectomy surgery having a desirable effect on
the prognosis (10).
We found a positive correlation between lymphovascular invasion and EGFR
expression in the cervical metastasis (p=0.028). This is in congruity
with the results of Ozdek et al which found that lymphovascular invasion
is a risk factor for occult metastasis and is a histological feature
that indicates an aggressive behavior of the carcinoma as tumor cells
access the blood and lymph vessels causing lymphatic and distant spread
altering the prognosis of the patients (11).
We examined the membranous expression of EGFR in the LSCC primary tumor
masses using immunohistological analysis. It was revealed that 70% of
the specimens had positive reaction to the EGFR antibody. Zimmermann et
al. asserted that nearly 80% of the head and neck carcinomas are
associated with an elevated expression of EGFR (12).
We noticed that 100% of the study sample who revealed to have positive
EGFR expression in their cervical lymph node metastasis had positive
membranous EGFR expression in their primary tumor with statistically
significant correlation (p=0.001). Şimşek H et al correlated the
aggressive behavior the tumor expresses in the matters of poorer
differentiation, increased tumor volume and cartilage, lymphovascular
and muscle invasion and metastasis to tumor EGFR expression(13).