Posted on Wed, May 16, 2012
Interesting article addressing this question is now available as "Full Free Text" from Clin Cancer Res Published OnlineFirst April 29, 2011.
Original summary on MDLinx:
Holdhoff M et al. –Mutant tumor-specific DNA can be detected beyond the visible tumor margin, but never beyond 4 mm, even in patients whose tumors were larger prior to chemotherapy. These data provide a rational basis for determining the extent of surgical excision required in patients undergoing resection of liver metastases.
Methods
- Evaluated 88 samples of tumor margins from 12 patients with metastatic colon cancer who each underwent partial hepatectomy of one to 6 liver metastases
- Punch biopsies of surrounding liver tissue obtained at 4, 8, 12 and 16 mm from the tumor border
- DNA from these biopsies analyzed by sensitive PCR-based technique, called BEAMing, for mutations of KRAS, PIK3CA, APC, or TP53 identified in corresponding tumor
Results
- Mutations were identified in each patient's resected tumor and used to analyze the 88 samples circumscribing the tumor-normal border
- Tumor-specific mutant DNA was detectable in surrounding liver tissue in five of these 88 samples, all within 4 mm of the tumor border
- Biopsies 8, 12, and 16 mm from macroscopic visible margin were devoid of detectable mutant tumor DNA as well as of microscopically visible cancer cells
- Tumors with significant radiologic response to chemotherapy were not associated with any increase in mutant tumor DNA in beyond 4 mm of main tumor
Read the full article
here.