I'm not a doctor...but I play one at work.

[mostuff]

Does the post-radiation status of colorectal tumors affect the accuracy of K-ras mutation analysis?

If anyone knows the answer, please let me know.

I'm not having much luck with my research.

Comments

[aedynn]

Does this help:

Genetic aberrations in radiation-associated colorectal cancer have not been studied in detail. We analyzed genetic aberrations in five rectal cancers that developed long after radiotherapy had been performed for cervical cancer. Microsatellite instability (MSI) in tumors was examined at five loci: D2S123, D3S966, TP53, DCC, and BAT26. Mutation of simple repeat sequences within the hMSH3, BAX, and transforming growth factor β type II receptor (TGFβRII) genes was examined by polymerase chain reaction and single-strand conformation polymorphism (PCR-SSCP). Mutation of p53 exons 5-8 was examined by PCR-SSP and direct sequencing. Mutations of the K-ras gene were analyzed by two-step PCR. No MSI was found in tumor specimens at any of the loci examined, and no mutations in the target genes were observed. K-ras mutation was detected in two carcinomas, but not in their irradiated normal mucosa, while p53 mutation was observed in another two carcinomas, but not in their irradiated normal mucosa. Our results suggest that the radiation-associated rectal carcinomas examined in this study did not develop through the mutator phenotype pathway; rather, tumorigenesis was probably mediated through the multistep carcinogenesis pathway.

Revue / Journal Title
Journal of gastroenterology ISSN 0944-1174 CODEN JOGAET
Source / Source
2003, vol. 38, no12, pp. 1185-1188 [4 page(s) (article)]

[mostuff]

I saw that one...that's dealing with colorectal cancers that were CAUSED by radiation...after treatment for cervical cancer.

I need to know how the K-ras test is affected by post-treatment radiated tissue.

I've got a call in to the molecular-genetics lab at LabCorp...just waiting for them to call me back.

Thanks, though! :)