BMC Cancer 2007, 7:226 http://www.biomedcentral.com/1471-2407/7/226 FCilguustreerin4g of carcinoma entities by their overall imbalance pattern Clustering of carcinoma entities by their overall imbalance pattern. For each of the selected chromosomal regions, aberrations were summarized (percent gain – percent loss). After normalization of all regions over the respective entity, the color intensi- ties represent the relative contribution of regional gains and losses to the overall aberration patterns. While 5p gains were found in various entities, gains on 5q were frequent only in ca. of thyroid and kidney, as were gains on chromosome 12. Overall, 13q losses could be detected in most entities. In contrast, 13q gains were pre- dominant in cholangio ca. and also frequent in colorectal and gastric carcinomas. Region specific gains involving 11q13 were found in a number of entities (bladder ca., HNSCC, pancreas, pros- tate, skin, ovary, gastric, NSCLC). Interestingly, of the overall 692 cases with gain on 11q13, 18% had a loss of the telomer of 11q by CGH (Figure 6). Since a strong selective pressure for such a switch in aberration quality in linked regions can be suspected, this observation may point towards targeting of both genes with oncogene and tumor suppressor functions on 11q in these tumors. a common pattern offrequent losses on 3p, gains on 3q, 8q and varying gains on 1q and 5p. NPC showed a slightly diverging pattern, with predominant 12p gains and 14q losses in addition to slightly lower levels of those imbal- ances. Interestingly, in both unselected renal carcinomas as thy- roid neoplasias, the average imbalance profiles included frequent gains on chromosomes 5, 7 and 12, while lack- ing the dominance of gains 1q and 8q found in most other entities. Apart from these observations, one should refer to the accompanying figures for a general comparison of pat- terns in different clinico-pathological groups. Also, the use of the Progenetix website tools is encouraged. When comparing overall aberration patterns, entities con- taining squamous cell carcinoma cases (HNSCC, NSCLC, cervix and vulva ca., esophagus ca.) appeared related, with Conclusion This study attempted an overview of chromosomal imbal- ance profiles in epithelial neoplasias, based on a large col- Page 10 of 15 (page number not for citation purposes)