DNA ploidy of primary and recurrent irradiated laryngeal tumors.
OBJECTIVE
Radiosensitivity of diploid laryngeal cancers, as compared with that of aneuploid ones, appears to be increased. However, no conclusive data exist. If a causal relationship exists, then recurrent laryngeal cancer after irradiation should predominantly be characterized by aneuploidy.


METHODS
To test this hypothesis we compared ploidy of 24 primarily irradiated laryngeal cancers and their subsequent recurrences. T and N stages were assessed in accordance with the TNM classification system of the UICC. With flow cytometry DNA ploidy was assessed.


RESULTS
1. Ploidy of 16 locally recurrent tumors did not differ from those of primary tumors, i.e. ten and six recurrences of diploid and aneuploid primary tumors, respectively, remained unchanged, 2. recurrences of four aneuploid primary tumors showed diploidy, 3. recurrences of four diploid primary tumors showed aneuploidy.


CONCLUSIONS
The results of our study do not support the hypothesis that recurrent laryngeal cancer after irradiation of the primary tumor is characterized by aneuploidy.
Struikmans
Henk
H
Department of Radiotherapy, University Medical Center, Utrecht, The Netherlands. H.STRUIKMANS@RADCL.RUU.NL
Hordijk
Gert J
GJ
Kal
Henk B
HB
D000782:Aneuploidy; D016009:Chi-Square Distribution; D004273:DNA, Neoplasm / Q000032:analysis*; D004171:Diploidy; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007822:Laryngeal Neoplasms / Q000235:genetics* / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D011836:Radiation Tolerance
D004273:DNA, Neoplasm