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EDITORIAL COMMENTS There are surprisingly few studies on the expression of

epidermal growth factor receptors in colorectal cancers. The study by Nakae and colleagues makes an important contribution toward a better understanding of the biology and prognosis of these cancers. The observation that an- euploidy correlates with lymph node metastasis, whereas c-erbB-2 overexpression correlates with distant metasta- sis is exciting. An important question is whether the colorectal primary cancers begin as EGFR and c-erbB-2 positive or acquire this phenotype as the disease progresses. A deviation from their observation in a small sample of colon cancers that we grew in nude mice is that EGFR status did not correlate with the ability to grow in nude mice. Furthermore, in two cases, EGFR originally present in the donor tumor was lost upon transplantation into the mice. Nevertheless, the studies by Nakae can form a basis for larger studies.

Satya Murthy, PhD

Department of Surgery Evanston Hospital

Evanston, Illinois 60201