Radiation therapy induced micronuclei in cervical cancer--does it have a predictive value for local disease control?
OBJECTIVE
To evaluate the predictive value of serial changes in micronuclei induction during external radiotherapy (EXRT) in cervical cancer with respect to local response at the end of EXRT and local disease free survival (LDFS).


METHODS
Twenty-five patients of squamous cell cancer of the cervix were treated by 50 Gy of EXRT delivered over 5 weeks followed by intracavitary brachytherapy. Serial cytological smears were taken from cervical growth at weekly intervals during the course of EXRT and stained by Giemsa and May-Grunwald's stain. Micronuclei induction were scored as (a) number of cells expressing micronuclei (MN), and (b) total number of micronuclei (TMN) in 1000 tumor cells from each of the serial smears.


RESULTS
A significant rise in micronuclei count was seen for both MN and TMN from pretreatment (week 0) to successive weeks of EXRT. For those having a near total tumor regression by end of EXRT, a significant rise in micronuclei was evident even at the end of first week of EXRT (MN: P = 0.05, TMN: P = 0.04). A superior LDFS was observed in patients showing greater than 50% increment in MN value in the first week (median survival for <50% vs. > or =50% rise: 5 months vs. not reached, P = 0.21), while it reached significance for a similar rise of TMN (median survival <50% vs. > or =50% rise: 5 months vs. not reached, P = 0.04).


CONCLUSIONS
The significant rise of micronuclei at the end of first week of EXRT in cervical cancers as observed from serial cytological smears could predict for a better local response and LDFS.
Singh
Shalini
S
Department of Radiotherapy, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Rae Barelli Road, Lucknow-226014, UP, India.
Datta
Niloy R
NR
Krishnani
Narendra
N
Lal
Punita
P
Kumar
Shaleen
S
D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D048629:Micronuclei, Chromosome-Defective; D015162:Micronucleus Tests / Q000379:methods; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D002583:Uterine Cervical Neoplasms / Q000473:pathology / Q000532:radiotherapy*