Expression of c-myc oncoprotein in laryngeal squamous cell carcinoma.
OBJECTIVE
c-myc seems to play a pivotal role in normal growth and development as well in cellular transformation and carcinogenesis. Overexpression of the c-myc oncogene has been observed in many hematopoetic and solid tumors. The role of c-myc protein in squamous cell carcinoma of the head and neck in general and laryngeal squamous cell carcinomas (LSCCs) in particular is far from clear. The aim of this study was to evaluate the relations between the level of c-myc protein in LSCCs and the clinicopathological data of patients, DNA ploidy and the SG2M phase index (PI).


METHODS
The c-myc protein level was evaluated immunohistochemically in tumor specimens from 50 patients with LSCC. The DNA index and SG2M PI were determined by means of flow cytometry.


RESULTS
We found c-myc protein in 34 (68%) tumors. Expression of c-myc protein was demonstrated to be frequent in nonmetastatic cases (p = 0.016). There was no association between c-myc protein level and age, primary tumor size, histological grading or type of cancer. In 13 (26%) cases we observed DNA aneuploid tumors. The mean value of the SG2M PI was 22.5%. Expression of c-myc protein was not related to SG2M PI or DNA ploidy.


CONCLUSIONS
We have shown that c-myc oncoprotein may be involved in the genesis of LSCC. Our findings suggest that the detectability of c-myc protein is associated with a lower metastatic potential. The c-myc oncogene is probably not as important in laryngeal cancers compared to other cancers. Further investigations must be performed to establish the value of predicting nodal metastases in LSCC.
Krecicki
Tomasz
T
Department and Clinic of Otolaryngology, Wroclaw Medical University, Wroclaw, Poland. krecicki@orl.am.wroc.pl
Fraczek
Marcin
M
Jelen
Michal
M
Zatonski
Tomasz
T
Szkudlarek
Teresa
T
Dus
Danuta
D
D000782:Aneuploidy; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D004171:Diploidy; D005260:Female; D005434:Flow Cytometry; D016195:G2 Phase; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D007822:Laryngeal Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis* / Q000235:genetics; D016196:S Phase
D016271:Proto-Oncogene Proteins c-myc