BMC Cancer 2007, 7:226 http://www.biomedcentral.com/1471-2407/7/226 aFCbilguerusrtreaernitn3ginoofn5e04o3r smeavleigrnaalnetnteiptiietshe(lriealf.nteaoblpelsas2ia+s b3y) the pattern of gains and losses, using regions previously defined as highly Clustering of 5043 malignant epithelial neoplasias by the pattern of gains and losses, using regions previously defined as highly aberrant in one or several entities (ref. tables 2 + 3). For each case (x-axis), gains (green) and losses (red) are indicated for the corresponding chromosomal regions (55 selected bands; y-axis). The color bar codes on top indicate the cases' assignments to the different clinico-pathological entities and histological groups (color code is provided in the additional file 1). quent imbalances in the respective entities. Hovever, they were rarely detected in neuroendocrine carcinomas and thyroid neoplasias. Interestingly, in some entities the maximum of detected abnormalities mapped proximal of 8q24 (e.g. 8q21 in melanocytic NPL and 8q22 in NPC and cholangio ca.). How much this reflects a true differ- ence in regional involvement, and therefore may point to differential target gene involvement has to be left open here. Gains on 1q with maxima on 1q2 were also frequent, and were the most frequent changes in breast, hepatocellular and endometrial carcinomas. However, 1q gains were comparatively infrequent in carcinomas of the prostate and bile ducts as well as in renal and colorectal ca. Overall gains on 3q26q27 combined with losses on 3p were char- acteristic for squamous cell carcinomas and SCLC, with 3q gains also being frequent in ovarial ca. and other enti- ties. Table 3: Selected imbalances with high penetrance limited to one or few entities Imbalance dim(2q22q31) dim(2q33q37) enh(5q21q35) dim(10q) enh(13q) Occurrence SCLC (up to 31.8%) Cervix (up to 30.1%) RCC (up to 32.8%) SCLC (up to 41.3%), melanocytic, endometrial CRC (up to 38.6%), gastric Comment Profile appears region-specific; however, SCLC cases have very rich imbalance pattern with more frequent changes Specific terminal 2q deletions are else only found in low frequency in NSCLC and bladder lesions Specific regional 5q gains are near exclusive for renal carcinomas, and are here part of whole chromosomal changes (20%) or limited to the region Rare as specific changes above "background" 13q gains are rare except in CRC, esp. compared to the frequent losses in the region Page 9 of 15 (page number not for citation purposes)