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CK7 protein expression in colorectal cancer: a marker for progression of colorectal cancer
1714
Correspondence
FEA may occur in isolation, our study emphasizes the fact that it is associated with ADH in most of the cases. In our cohort, based on 14-gauge needle core biopsy specimens, 7 of 46 cases of ADH with or without FEA and 3 of 14 cases of pure FEA were upgraded to carcinoma. These numbers are higher than those reported by Zografos et al (1/33 for ADH with or without FEA and 0/18 for pure FEA). One reason for this difference could be the fact that the diagnosis of FEA and ADH in their cohort was established by 11-gauge vacuumassisted breast biopsy, which extracts a larger amount of tissue. Another possible reason for this difference could be that the populations of these two studies are different, as the study population of Zografos is European while ours is from the United States. It only makes sense to compare two rates when two sample populations and other factors are all the same. Importantly, despite these differences both studies found that FEA and ADH exhibit a similar risk of upgrade to carcinoma, indicating that our conclusion holds true despite the fact that two different populations were analyzed. We also concur with Zografos et al that one of the main limitations of these studies are methodological in nature. Although power analyses are important, they present several practical problems. The problem with these techniques is that they require an accurate estimate of the size of the difference you are looking for (the “effect size”). When conducting biological research, the investigators usually do not know how big a difference is expected. Hence, although the concept of power analyses is desirable, it is hard to objectively assess the results. We believe that the most reliable way of validating biological research is with large, preferably multi-institutional collaborative studies that include a large sample size (a practical way of reducing type II errors) and/or multiple studies coming to the same conclusion [4]. Therefore, in spite of methodological and populationrelated differences, the fact that the findings appear to point in the same direction is indeed encouraging. Lakshmi Kunju Ying Ding Celina G. Kleer doi:10.1016/j.humpath.2008.07.006
CK20/CK7 protein expression in colorectal cancer: a marker for progression of colorectal cancer Dear Editor, We read with great interest the article by Hernandez [1] in which cytokeratin 20 (CK20) and cytokeratin 7 (CK7) protein expression in colorectal cancer was studied. They concluded that advanced colorectal cancers were more likely to have CK20+/CK7+ profiles than early-stage cancers, which were predominantly CK20+/CK7-. They indicated that CK7 expression may be a marker for the progression of colorectal cancer, but no conclusions were provided for rare cases of colorectal tumors with a CK20-/CK7+ profile. We recently observed a primary right colonic adenocarcinoma in a 70-year-old female patient. The tumor was entirely composed of a poorly differentiated adenocarcinoma. Tumor stage was T3 N2 Mx. Immunohistochemistry eliminated a metastatic adenocarcinoma. We observed diffuse cytoplasmic strong positivity for cytokeratin 7 but no staining for cytokeratin 20, progesterone and estrogen receptors, and TTF1. In 2 of 8 metastatic lymph nodes, we noted well-differentiated colonic adenocarcinoma with a CK20 + /CK7- profile. Other metastatic lymph nodes were composed of the poorly differentiated contingent with a CK7+ /CK20 - profile. CK20- /CK7+ profile staining is more likely in lung, breast, ovary, and endometrial tumors [2], but few cases of primary colonic adenocarcinoma with the same profile have been reported. This expression pattern appeared to be more common in right-sided carcinoma than in leftsided carcinoma [2], and most of these cases consisted of high-grade carcinoma [2]. In the reported case, the coexistence of a well-differentiated adenocarcinoma (CK7- /CK20 + ) with a poorly differentiated contingent (CK7+ /CK20- ) shows the primary colonic tumor origin. Furthermore, CK7 expression, as well as the loss of expression of CK20, may be a marker for the progression of colorectal cancer. Aude Bressenot MD Olivia Zimmer Department of Pathology, CHU Nancy-Brabois 54511 Vandoeuvre Cedex, France
References
doi:10.1016/j.humpath.2008.07.010
[1] Zografos GC, Zagouri F, Sergentanis TN, Nonni A, Koulochori D, Fotou M, et al. Minimizing underestimation rate of microcalcifications excised via vacuum-assisted breast biopsy: a blind study. Breast Cancer Res Treat 2007 [Epub ahead of print]. [2] Zografos GC, Zagouri F, Sergentanis TN, Nonni A, Koulochori D, Bramis J. Atypical ductal hyperplasia: a way to minimize underestimation in vacuum-assisted breast biopsy? Breast 2008;17:6. [3] Kunju LP, Kleer CG. Significance of flat epithelial atypia on mammotome core needle biopsy. HUM PATHOL 2007;38:35-41. [4] Allchin D. “Error types”, Perspectives on science, vol. 9, No.1; 2001. p. 38-58.
References [1] Hernandez BY, Frierson HF, Moskaluk CA, et al. CK20 and CK7 protein expression in colorectal cancer: demonstration of the utility of a population-based tissue microarray. HUM PATHOL 2005;36: 275-81. [2] Park SY, Kim HS, Hong EK, et al. Expression of cytokeratins 7 and 20 in primary carcinomas of the stomach and colorectum and their value in the differential diagnosis of metastatic carcinomas to the ovary. HUM PATHOL 2002;33:1078-85.
Correspondence
FEA may occur in isolation, our study emphasizes the fact that it is associated with ADH in most of the cases. In our cohort, based on 14-gauge needle core biopsy specimens, 7 of 46 cases of ADH with or without FEA and 3 of 14 cases of pure FEA were upgraded to carcinoma. These numbers are higher than those reported by Zografos et al (1/33 for ADH with or without FEA and 0/18 for pure FEA). One reason for this difference could be the fact that the diagnosis of FEA and ADH in their cohort was established by 11-gauge vacuumassisted breast biopsy, which extracts a larger amount of tissue. Another possible reason for this difference could be that the populations of these two studies are different, as the study population of Zografos is European while ours is from the United States. It only makes sense to compare two rates when two sample populations and other factors are all the same. Importantly, despite these differences both studies found that FEA and ADH exhibit a similar risk of upgrade to carcinoma, indicating that our conclusion holds true despite the fact that two different populations were analyzed. We also concur with Zografos et al that one of the main limitations of these studies are methodological in nature. Although power analyses are important, they present several practical problems. The problem with these techniques is that they require an accurate estimate of the size of the difference you are looking for (the “effect size”). When conducting biological research, the investigators usually do not know how big a difference is expected. Hence, although the concept of power analyses is desirable, it is hard to objectively assess the results. We believe that the most reliable way of validating biological research is with large, preferably multi-institutional collaborative studies that include a large sample size (a practical way of reducing type II errors) and/or multiple studies coming to the same conclusion [4]. Therefore, in spite of methodological and populationrelated differences, the fact that the findings appear to point in the same direction is indeed encouraging. Lakshmi Kunju Ying Ding Celina G. Kleer doi:10.1016/j.humpath.2008.07.006
CK20/CK7 protein expression in colorectal cancer: a marker for progression of colorectal cancer Dear Editor, We read with great interest the article by Hernandez [1] in which cytokeratin 20 (CK20) and cytokeratin 7 (CK7) protein expression in colorectal cancer was studied. They concluded that advanced colorectal cancers were more likely to have CK20+/CK7+ profiles than early-stage cancers, which were predominantly CK20+/CK7-. They indicated that CK7 expression may be a marker for the progression of colorectal cancer, but no conclusions were provided for rare cases of colorectal tumors with a CK20-/CK7+ profile. We recently observed a primary right colonic adenocarcinoma in a 70-year-old female patient. The tumor was entirely composed of a poorly differentiated adenocarcinoma. Tumor stage was T3 N2 Mx. Immunohistochemistry eliminated a metastatic adenocarcinoma. We observed diffuse cytoplasmic strong positivity for cytokeratin 7 but no staining for cytokeratin 20, progesterone and estrogen receptors, and TTF1. In 2 of 8 metastatic lymph nodes, we noted well-differentiated colonic adenocarcinoma with a CK20 + /CK7- profile. Other metastatic lymph nodes were composed of the poorly differentiated contingent with a CK7+ /CK20 - profile. CK20- /CK7+ profile staining is more likely in lung, breast, ovary, and endometrial tumors [2], but few cases of primary colonic adenocarcinoma with the same profile have been reported. This expression pattern appeared to be more common in right-sided carcinoma than in leftsided carcinoma [2], and most of these cases consisted of high-grade carcinoma [2]. In the reported case, the coexistence of a well-differentiated adenocarcinoma (CK7- /CK20 + ) with a poorly differentiated contingent (CK7+ /CK20- ) shows the primary colonic tumor origin. Furthermore, CK7 expression, as well as the loss of expression of CK20, may be a marker for the progression of colorectal cancer. Aude Bressenot MD Olivia Zimmer Department of Pathology, CHU Nancy-Brabois 54511 Vandoeuvre Cedex, France
References
doi:10.1016/j.humpath.2008.07.010
[1] Zografos GC, Zagouri F, Sergentanis TN, Nonni A, Koulochori D, Fotou M, et al. Minimizing underestimation rate of microcalcifications excised via vacuum-assisted breast biopsy: a blind study. Breast Cancer Res Treat 2007 [Epub ahead of print]. [2] Zografos GC, Zagouri F, Sergentanis TN, Nonni A, Koulochori D, Bramis J. Atypical ductal hyperplasia: a way to minimize underestimation in vacuum-assisted breast biopsy? Breast 2008;17:6. [3] Kunju LP, Kleer CG. Significance of flat epithelial atypia on mammotome core needle biopsy. HUM PATHOL 2007;38:35-41. [4] Allchin D. “Error types”, Perspectives on science, vol. 9, No.1; 2001. p. 38-58.
References [1] Hernandez BY, Frierson HF, Moskaluk CA, et al. CK20 and CK7 protein expression in colorectal cancer: demonstration of the utility of a population-based tissue microarray. HUM PATHOL 2005;36: 275-81. [2] Park SY, Kim HS, Hong EK, et al. Expression of cytokeratins 7 and 20 in primary carcinomas of the stomach and colorectum and their value in the differential diagnosis of metastatic carcinomas to the ovary. HUM PATHOL 2002;33:1078-85.