| 1. |
- Bagwell, C B, et al.
(författare)
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Optimizing flow cytometric DNA ploidy and S-phase fraction as independent prognostic markers for node-negative breast cancer specimens
- 2001
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Ingår i: Cytometry. - : Wiley. - 0196-4763 .- 1097-0320. ; 46:3, s. 121-135
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Tidskriftsartikel (refereegranskat)abstract
- Developing a reliable and quantitative assessment of the potential virulence of a malignancy has been a long-standing goal in clinical cytometry. DNA histogram analysis provides valuable information on the cycling activity of a tumor population through S-phase estimates; it also identifies nondiploid populations, a possible indicator of genetic instability and subsequent predisposition to metastasis. Because of conflicting studies in the literature, the clinical relevance of both of these potential prognostic markers has been questioned for the management of breast cancer patients. The purposes of this study are to present a set of 10 adjustments derived from a single large study that optimizes the prognostic strength of both DNA ploidy and S-phase and to test the validity of this approach on two other large multicenter studies. Ten adjustments to both DNA ploidy and S-phase were developed from a single node-negative breast cancer database from Baylor College (n = 961 cases). Seven of the adjustments were used to reclassify histograms into low-risk and high-risk ploidy patterns based on aneuploid fraction and DNA index optimum thresholds resulting in prognostic P values changing from little (P < 0.02) or no significance to P < 0.000005. Other databases from Sweden (n = 210 cases) and France (n = 220 cases) demonstrated similar improvement of DNA ploidy prognostic significance, P < 0.02 to P < 0.0009 and P < 0.12 to P < 0.002, respectively. Three other adjustments were applied to diploid and aneuploid S-phases. These adjustments eliminated a spurious correlation between DNA ploidy and S-phase and enabled them to combine independently into a powerful prognostic model capable of stratifying patients into low, intermediate, and high-risk groups (P < 0.000005). When the Baylor prognostic model was applied to the Sweden and French databases, similar significant patient stratifications were observed (P < 0.0003 and P < 0.00001, respectively). The successful transference of the Baylor prognostic model to other studies suggests that the proposed adjustments may play an important role in standardizing this test and provide valuable prognostic information to those involved in the management of breast cancer patients.
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| 2. |
- Baldetorp, Bo, et al.
(författare)
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DNA and cell cycle analysis as prognostic indicators in breast tumors revisited
- 2001
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Ingår i: Clinics in Laboratory Medicine. - 0272-2712 .- 1557-9832. ; 21:4, s. 875-
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Tidskriftsartikel (refereegranskat)abstract
- Both DNA ploidy and S-phase ploidy are promising prognostic factors for node-negative breast cancer patients. Based largely on the analysis of one large study, much of the reported problems with these factors have been caused by some unappreciated complexities in categorizing DNA ploidy into low- and high-risk groups and the lack of some necessary adjustments to eliminate unwanted correlations between DNA S-phase and ploidy. When both DNA ploidy and S-phase are compensated properly, they become independent prognostic markers, forming a powerful prognostic model.
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| 3. |
- Tanner, M M, et al.
(författare)
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Genetic aberrations in hypodiploid breast cancer: frequent loss of chromosome 4 and amplification of cyclin D1 oncogene
- 1998
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Ingår i: American Journal of Pathology. - 1525-2191. ; 153:1, s. 191-199
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Tidskriftsartikel (refereegranskat)abstract
- The evolution of somatic genetic aberrations in breast cancer has remained poorly understood. The most common chromosomal abnormality is hyperdiploidy, which is thought to arise via a transient hypodiploid state. However, hypodiploidy persists in 1 to 2% of breast tumors, which are characterized by a poor prognosis. We studied the genetic aberrations in 15 flow cytometrically hypodiploid breast cancers by comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). Surprisingly, numerous copy number gains were detected in addition to the copy number losses. The number of gains per tumor was 4.3 +/- 3.2 and that of losses was 4.5 +/- 3.3 (mean +/- SD), which is similar to that previously observed in hyperdiploid breast cancers. Gains at chromosomes or chromosomal regions at 11q13, 1q, 19, and 16p and losses of 2q, 4, 6q, 9p, 13, and 18 were most commonly observed. Compared with unselected breast carcinomas, hypodiploid tumors showed certain differences. Loss of chromosome 4 (53%) and gain of 11q13 (60%) were significantly more common in hypodiploid tumors. The gain at 11q13 was found by FISH to harbor amplification of the Cyclin D1 oncogene, which is therefore three to four times more common in hypodiploid than in unselected breast cancers (15 to 20%). Structural chromosomal aberrations (such as Cyclin D1 amplification) were present both in diploid and hypodiploid tumor cell populations, as assessed by FISH and CGH after flow cytometric sorting. Together these results indicate that hypodiploid tumors form a distinct genetic entity of invasive breast cancer, although they probably share a common genetic evolution pathway where structural chromosomal aberrations precede gross DNA ploidy changes.
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