High S-phase Fraction Research Articles

Combined flow cytometry determination of S-phase fraction and DNA ploidy is an independent prognostic factor in node-negative invasive breast carcinoma: analysis of a series of 271 patients with stage I and II breast cancer

To assess the significance of S-phase fraction (SPF) and DNA ploidy evaluated by DNA flow cytometry as prognostic markers in stage I or II breast cancer. A series of 271 patients, treated by surgery, radiotherapy +/- systemic therapy was analyzed (median follow up: 64 months). Standardized flow cytometry cell preparation from frozen samples and consensus rules for data interpretation were followed. Three SPF classes were defined on the basis of tertiles after adjustment for ploidy. Four groups were defined based on combinations of DNA ploidy (DIP: diploid; ANEUP: aneuploid) and SPF: DIP and low SPF (DL, n=37), DIP and medium or high SPF (DMH, n=76), ANEUP and low SPF (AL, n=24), ANEUP and medium or high SPF (AMH, n=68). Local control rate (LCR), disease-free survival (DFS), metastasis-free survival (MFS), and overall survival (OS) were correlated with DNA ploidy, SPF, DL to AMH groups, T and N stages, SBR grading, age, and hormonal status on univariate and multivariate analysis (Cox model). On univariate analysis, DFS and LCR were higher for DIP tumours. High SPF values were associated with shorter DFS. LCR, MFS, DFS, and OS rates were significantly different with an increasingly poorer prognosis from DL to AMH. On multivariate analysis, groups DL to AMH, histological node involvement and T stage were independently associated with MFS, and DFS. In N- patients, DL to AMH remained independent for MFS and DFS. For SBR III tumours, MFS and OS were significantly different in DL to AMH groups. These results strongly support the use of combined evaluation of DNA ploidy and SPF as independent parameters in clinical trials for N- stage I and II breast cancer.

Tissue-Type plasminogen activator (tPA) in breast cancer: relationship with clinicopathological parameters and prognostic significance

Tissue-type plasminogen activator (tPA) is a serine protease primarily involved in the intravascular dissolution of blood clots. High intratumoral tPA levels are associated with prognosis in several human tumors. In addition, tPA has been shown to be an estrogen-inducible protein in human breast cancer cell lines. The aim of the present study was to analyze the cytosolic tPA content in primary breast carcinomas and its potential clinical value. tPA was measured by a solid-phase enzyme immunoassay in tumor cytosol samples obtained from 800 patients with breast cancer. The median follow-up period was of 49.2 months. Cytosolic tPA levels ranged widely in breast carcinomas (median: 3.9; range: 0.1- 315.3 ng/mg protein). tPA levels were significantly lower in large tumors, as well as in those showing poor differentiation, estrogen (ER) or PgR-negativity, aneuploidy, or a high S-phase fraction. In addition, low tPA intratumoral levels were associated with a high probability of both shortened relapse-free and overall survival in all patients and in the subgroup with node-negative tumors. However, our results did not show any significant relationship between intratumoral tPA levels and prognosis in the different subgroups of patients, stratified according to the type of systemic adjuvant therapy received (chemotherapy, tamoxifen or chemotherapy plus sequential tamoxifen). The results of the present investigation indicate that low intratumoral tPA levels are associated with aggressiveness and poor prognosis in breast cancer patients. However, the study suggests that tPA levels do not predict response to systemic adjuvant therapy.

Relationships of tumor inflammatory infiltration and necrosis with microsatellite instability in colorectal cancers

The relationships between microsatellite instability (MSI) and survival in colorectal cancer patients are not consistent. The favorable survival of patient with MSI has been suggested to be related to pronounced inflammatory infiltration; however, the reason for non-association of MSI with survival is unclear. Our aims were to investigate the associations of inflammatory infiltration and tumor necrosis (TN) with microsatellite status and clinicopathological factors in colorectal cancer patients in whom MSI was not related to survival. Three hundred and one colorectal adenocarcinomas were evaluated for inflammatory infiltration and 300 for TN under light microscope. Low infiltration at invasive margin (chi2 = 3.94, P = 0.047) and in whole tumor stroma (chi2 = 3.89, P = 0.049) was associated with MSI, but TN was not (chi2=0.10, P = 0.75). Low infiltration was related to advanced stage (chi2 = 8.67, P = 0.03), poorer differentiation (chi2 = 8.84, P = 0.03), DNA non-diploid (chi2 = 10.04, P = 0.002), higher S-phase fraction (chi2 = 11.30, P = 0.004), positive p53 expression (chi2 = 7.94, P = 0.01), and worse survival (P = 0.03 for both univariate and multivariate analyses). Abundant TN was related to advanced stage (chi2 = 17.74, P = 0.001) and worse survival (P = 0.02 for univariate, and P = 0.05 for multivariate analysis). The result that high inflammatory infiltration was not related to MSI might help explain the non-association of MSI with survival in colorectal cancer patients.

DNA ploidy analysis and expression of MMP-9, TIMP-2, and E-cadherin in gastric carcinoma

To investigate DNA ploidy and expression of MMP-9, TIMP-2, and E-cadherin in gastric carcinoma and to explore the mechanism of invasion and metastasis of gastric carcinoma. Immunohistochemical methods were used to detect the expressions of MMP-9, TIMP-2, and E-cadherin in 156 cases, including 99 cases of gastric carcinoma, 16 cases of adjacent noncancerous mucosa, 16 cases of distant metastases and 25 cases of metastatic lymph node (LN) from gastric carcinoma. Flow cytometry DNA ploidy and S-phase fraction (SPF) analysis were performed on 57 cases, including 47 cases of gastric cancer, 6 cases of adjacent noncancerous mucosa, and 4 cases of distant metastatic cancer. The expression of MMP-9 was significantly correlated with Lauren's classification, Borrmann's classification, LN metastasis, tumor metastasis, and TNM stage, as well as depth of invasion (all P<0.05). The positive rate was lower in noncarcinoma than in carcinoma (31.3% vs 66.7%, P<0.01). The expression of TIMP-2 was significantly correlated with Borrmann's classification, LN metastasis, and the depth of invasion (all P<0.05). The expression of E-cadherin was significantly correlated with differentiation, Lauren's classification, Borrmann's classification, and LN metastasis, as well as the depth of invasion (P<0.01 or P<0.05). E-cadherin was less expressed in carcinoma than in noncarcinoma (42.4% vs 87.5%, P<0.01). There was a positive correlation between MMP-9 and TIMP-2 and a negative correlation between MMP-9 and E-cadherin, but no correlation between TIMP-2 and E-cadherin. Also there was a positive correlation between DNA aneuploid rate and differentiation and LN metastasis. SPF that was higher than 15% was positively correlated with tumor size, differentiation and LN metastasis. And there was a significant difference between carcinoma and noncarcinoma in DNA aneuploid rate and SPF. With tumor progression and development of heterogeneity, the abnormal expressions of MMP-9, TIMP-2, and E-cadherin or DNA aneuploid rate or high SPF gradually increases, suggesting that they play a crucial role in gastric carcinoma progression.

Prognostic value of uPA, PAI-1, and dna content in adult renal cell carcinoma

Objectives To examine whether urokinase-type plasminogen activator (uPA) and type 1 plasminogen inhibitor (PAI-1), DNA ploidy, and S-phase fraction (SPF) add supplementary prognostic information relative to stage and Fuhrman's grade in renal cell carcinoma. Methods A total of 100 patients with primary renal adenocarcinoma treated by nephrectomy were followed up for a median of 42 months. Of the 100 patients, 78 with Stage M0N0-Nx tumors were studied by multivariate analysis. The study population was dichotomized on the basis of the median cytosolic uPA and PAI-1 concentrations (30 pg/mg protein and 12.7 ng/mg protein, respectively). DNA content was measured by flow cytometry (FCM) on multiple tumor samples from each patient. DNA aneuploidy was observed in 67% of cases. The SPF was calculated for aneuploid samples. Results An FCM classification based on a combination of DNA content and SPF was obtained. High-risk patients were those with aneuploid tumors and high SPF values (greater than 1.7%) and included 23% of patients with M0N0-Nx tumors. Cytosolic uPA and PAI-1 levels were not predictive of metastasis. The stage, grade, SPF, and FCM classification were statistically significant prognostic factors in the univariate analysis, in both the overall population and the M0N0-Nx subgroup. In multivariate analysis, tumor grade and the FCM classification were the only independent predictors of disease-free survival ( P = 0.018 and P = 0.046, respectively). Conclusions We defined a group of M0N0-Nx patients with aneuploid tumors and high SPF values who are at a high risk of metastasis and who may benefit from closer long-term follow-up.

Stratification of the biologic aggressiveness of non-small cell lung cancer using DNA flow cytometry and immunohistochemistry for the retinoblastoma protein

DNA ploidy pattern and S-phase fraction (SPF) measured by flow cytometry and expression of the retinoblastoma gene product (pRB) estimated by immunohistochemistry were correlated with outcome in 114 patients who received a curative operation for primary non-small cell lung cancer (NSCLC). One hundred ten tumors yielded an adequate DNA histogram, and all tumors exhibited an assessable immunohistochemical stain. DNA diploidy was detected in 31 tumors and DNA aneuploidy in 79 tumors. The mean SPF was 14.1±6.4%. Eighty tumors were positively stained, and 34 tumors were negative for pRB. Multivariate analysis clarified that both TNM staging and DNA ploidy were prognostic factors after surgery. In 39 recurrent cases, the SPF value was inversely correlated with disease-free interval. With only supportive care after recurrence, high SPF tumors and pRB-negative tumors progressed rapidly, whereas active treatment yielded an equivalent effect on recurrent tumors regardless of the SPF or pRB expression. DNA ploidy is related to the risk of recurrence, while SPF is related to tumor growth rate and the impact of active treatment on recurrence. The utility of pRB expression was limited. The combination of DNA ploidy and SPF allows practical stratification of the biologic aggressiveness of NSCLC.

Application of the crypt isolation technique to the flow cytometric analysis of DNA content in gastric carcinoma

An inevitable limitation of conventional flow cytometric analysis of gastric cancer DNA content is that the preparations of tumor cell nuclei are contaminated with stromal cell nuclei. Using the crypt isolation technique, we separated tumor tissues from stromal tissues and analyzed the DNA content in samples of pure gastric cancer cells (64 intestinal-type and 46 diffuse-type) by flow cytometry. Morphologically, crypts from well-differentiated and moderately differentiated adenocarcinomas usually showed large tube-like or sheet structures, whereas tumor tissues isolated from poorly differentiated adenocarcinomas usually exhibited small tumor cell clumps or clusters of varying sizes. Tumor ploidy was divided into diploid, aneuploid, and multiploid subgroups. Aneuploidy and multiploidy were observed in 12% (13 of 110) and 64% (71 of 110) of gastric cancers, respectively. A high frequency of DNA aneuploidy or multiploidy was associated with intestinal-type tumors, but not with any of the other clinicopathologic variables tested. In contrast, high S-phase fraction values demonstrated a close association with tumors with abnormal ploidy, advanced stage, intestinal type, and late TNM stage. Our results suggest that S-phase fraction may be a more useful indicator of aggressive behavior in gastric cancers than DNA aneuploidy. To our knowledge, the present study is the first to report flow cytometric DNA content in a large number of gastric cancer samples obtained using the crypt isolation technique.

Stratification of the biologic aggressiveness of non-small cell lung cancer using DNA flow cytometry and immunohistochemistry for the retinoblastoma protein

<h2>Abstract</h2> DNA ploidy pattern and S-phase fraction (SPF) measured by flow cytometry and expression of the retinoblastoma gene product (pRB) estimated by immunohistochemistry were correlated with outcome in 114 patients who received a curative operation for primary non-small cell lung cancer (NSCLC). One hundred ten tumors yielded an adequate DNA histogram, and all tumors exhibited an assessable immunohistochemical stain. DNA diploidy was detected in 31 tumors and DNA aneuploidy in 79 tumors. The mean SPF was 14.1±6.4%. Eighty tumors were positively stained, and 34 tumors were negative for pRB. Multivariate analysis clarified that both TNM staging and DNA ploidy were prognostic factors after surgery. In 39 recurrent cases, the SPF value was inversely correlated with disease-free interval. With only supportive care after recurrence, high SPF tumors and pRB-negative tumors progressed rapidly, whereas active treatment yielded an equivalent effect on recurrent tumors regardless of the SPF or pRB expression. DNA ploidy is related to the risk of recurrence, while SPF is related to tumor growth rate and the impact of active treatment on recurrence. The utility of pRB expression was limited. The combination of DNA ploidy and SPF allows practical stratification of the biologic aggressiveness of NSCLC.

Amplification of the cyclin D1 gene is associated with tumour subsite, DNA non-diploidy and high S-phase fraction in squamous cell carcinoma of the head and neck

Amplification of CCND1 (cyclin D1 gene) in squamous cell carcinoma of the head and neck (SCCHN) is correlated to poor prognosis. The purpose of this study was to investigate whether CCND1 amplification is related to different subsites and also to DNA ploidy status and S-phase fraction (SPF). Biopsies from 67 patients with SCCHN were analysed for CCND1 amplification by fluorescence in situ hybridisation (FISH) and for ploidy status and SPF by flow cytometry (FCM). Twenty-one of 67 tumours (31%) showed CCND1 amplification and the frequencies differed significantly between different subsites ( p=0.01). Tumours from hypopharynx, larynx and oropharynx showed higher rates of amplification as compared to tumours from oral cavity and epipharynx. CCND1 amplification was also associated to DNA non-diploidy and high SPF ( p=0.002 and p=0.002, respectively). In conclusion, the rate of CCND1 amplification differed between different subsites in SCCHN and was also associated to a more aggressive tumour phenotype, as defined by DNA non-diploidy and high SPF.

Comparative cytogenetic and DNA flow cytometric analysis of 242 primary breast carcinomas

The cytogenetic and DNA flow cytometric findings in 242 breast carcinomas were compared. The combined use of both techniques improved the detection of abnormal cell populations from 65% by cytogenetic analysis alone and 59% by DNA flow cytometric analysis alone to 84%. Informative and comparable cytogenetic and flow cytometric data were obtained for 155 tumors. Among these 155 tumors, there was good concordance (64%) between the estimates of genomic changes by the two methods. Most discrepancies were among the DNA-diploid cases, where cytogenetic analysis detected small genomic changes. There were, however, also some exceptions in which large genomic changes detected by one method were missed by the other. Of the specific breast cancer–associated cytogenetic aberrations subjected to separate correlation analysis, polysomy for chromosome 20 was significantly associated with a high S-phase fraction, whereas loss of the long arm of chromosome 16 and/or the presence of a der(1;16) were significantly associated with a low S-phase fraction. Our data show that cytogenetic and DNA flow cytometric analyses of breast carcinomas give largely comparable results, and that combining data from both methods significantly improves the information obtained by either technique used alone on the genetic abnormalities in these tumors.

Overexpression of c-erbB-2 is related to a higher expression of vascular endothelial growth factor (VEGF) and constitutes an independent prognostic factor in primary node-positive breast cancer after adjuvant systemic treatment

The aim of this study was to investigate possible associations between the expression of c-erbB-2 and the angiogenic factors vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), p53 status, routine breast cancer prognostic factors and survival. Expression of c-erbB-2, VEGF, bFGF, and p53 protein was determined with an enzyme-linked immunosorbent assay (ELISA) in 656 patients with primary breast cancer (median follow-up time of 83 months). In 60 cases, we also used immunohistochemistry (IHC) for c-erbB-2 evaluation, to be used as a reference for the ELISA. Overexpression of c-erbB-2 was significantly related to a higher expression of VEGF, lower bFGF content, negative steroid receptor status, and a high S-phase fraction. In multivariate analysis, c-erbB-2 was an independent prognostic factor for relapse-free survival (RFS) and overall survival (OS) in all patients, and in node-positive patients, irrespective of the adjuvant systemic therapy. Combined survival analyses regarding c-erbB-2 and VEGF yielded additional prognostic information.

Oncological effects of insufflation with different gases and a gasless procedure in rats.

The validity of using carbon dioxide (CO2) pneumoperitoneum in laparoscopic tumor surgery has not been investigated thoroughly. The oncologic effects of a gasless procedure and insufflation with different gases were compared in rats. In all the experiments, Donryu rats were randomized to receive a gasless procedure; to receive insufflation with CO2, helium, or air at 10 mmHg for 30 min, or to serve as control subjects without insufflation. In experiment 1, involving 60 rats, ascites hepatoma AH130 cells were inoculated intraperitoneally just before the procedures. The S-phase fraction of the intraperitoneal tumor cells was determined using a flow cytometry on day 7. In experiment 2, 60 rats injected intraperitoneally with latex particles received one of the procedures. At the end of the procedure, peritoneal macrophages were harvested to determine the number of phagocytosed particles. In experiment 3, 75 rats inoculated intraperitoneally with AH130 cells received one of the procedures for 5 consecutive days and were followed for survival analysis. EXPERIMENT 1: The S-phase fraction was lower after insufflation with air or helium (p < 0.01) than with the anesthesia control condition. Insufflation with CO2 showed a higher S-phase fraction than the gasless procedure or insufflation with air or helium (p < 0.01). EXPERIMENT 2: The phagocytotic activity of peritoneal macrophages was increased by insufflation with helium and air, as compared with the control condition (p < 0.01). Insufflation with CO2 deteriorated the phagocytotic activity more than the gasless procedure (p < 0.05) or insufflation with air or helium (p < 0.001). EXPERIMENT 3: Insufflation with gases demonstrated shorter survival than the anesthesia control condition or the gasless procedure regardless of the gases used (p < 0.01). These results suggest that the choice of gases may affect the proliferation of tumor cells and the phagocytotic activity of peritoneal macrophages, insufflation itself may promote tumor spread regardless of the gases used, and the gasless procedure may be oncologically advantageous in this animal model.

Influence of tumor grade on expression of CA 125 in serum and tissue in patients with serous ovarian carcinoma.

The factors affecting CA 125 expression in tissue in serous carcinoma are not well known. The aim of our study was to establish how CA 125 expression in serum and tissue is affected by DNA-ploidy, proliferative activity of tumor cells, tumor grade and the stage of the disease. This retrospective study included 50 patients with ovarian carcinoma. The serum CA 125 level was determined preoperatively in all patients. Antigen expression in tissue was confirmed using CA 125-immunohistochemistry. Suspensions of nuclei were prepared from tissue sections and DNA-ploidy was determined using flow cytometry. Data were analyzed using nonparametric statistics and multivariant analysis. The average level of serum CA 125 was 674.5 U/ml and was significantly higher in advanced (p = 0.00044) and dedifferentiated (p = 0.00055) tumors and in tumors with a higher S-phase fraction (SPF) (p = 0.011). The mean percent of CA 125-positive cells in tissue was 38.3. CA 125 immunostaining was not related to tumor grade or DNA-ploidy. A positive CA 125 test in both tissue and serum was confirmed in 33 cases (66%). The correlation between expression of CA 125 in tissue and serum was weak (r = 0.28) and nonsignificant (p = 0.052). No reliable conclusions could be drawn on the influence of the studied parameters on expression of CA 125 in tissue and serum. The effect of tumor grade seems to be the strongest influence, particularly on CA 125 expression in serum, but it is not independent.

Maspin expression in invasive breast cancer: association with other prognostic factors.

Maspin is a unique serine protease inhibitor with a molecular weight of 42 kDa. It has been shown to inhibit tumour cell motility and invasion in cell culture, and tumour growth and metastasis in animal models. There is very limited data on the prognostic utility of maspin in human breast cancer. We performed a preliminary study to assess the associations of maspin with other established prognostic factors in invasive breast cancer (IBC). 1068 paraffin-embedded IBCs were immunohistochemically stained with a monoclonal antibody to maspin. A nuclear signal was present in 96% and a cytoplasmic signal in 35% of the cases. Nuclear staining was related to oestrogen (ER) and progesterone receptor (PR) positivity (p < 0.0001), but not to S-phase fraction (SPF) or ploidy. Cytoplasmic staining was related to ER and PR negativity (p < 0.0001), high SPF (p < 0.0001), and aneuploidy (p = 0.003). Thus, maspin nuclear staining was significantly associated with good prognostic factors, while cytoplasmic staining was associated with poor prognostic markers. These findings suggest that the presence of maspin in two different compartments of the cell may have different biological and clinical implications. Additional studies are needed to evaluate further this expression profile of maspin in breast cancer.

Flow cytometric DNA analysis for determination of malignant potential in adrenal pheochromocytoma or paraganglioma: an Indian experience.

We analyzed the histological features and DNA flow cytometric results in 34 patients with pheochromocytoma and paragangliomas and attempted correlation with the biological behavior for determination of the malignant potential of these tumors. DNA analysis was done on a FACSort flow cytometer using paraffin-embedded tissues. Histopathological analysis was performed using parameters, i.e., cell size (large, medium, and small), cell size variation, mitotic rate, nuclear pleomorphism, golden yellow to brown pigment in the tumor, necrosis, and venous invasion. Six tumors had high (>5/10HPF) mitotic rate while venous invasion was seen in three tumors. Fifty percent (18/34) of patients had aneuploid tumors, and 68% (23/34) of patients had high (>10%) S-phase fraction tumors. Aneuploidy correlated with >5/10HPF mitotic rate (P <.05) and diploidy with golden yellow to brown pigment (P <.01). The patients with aneuploid tumor had a worse prognosis than patients with diploid tumors (P =.004). No such difference was observed with low and high S-phase fractions (P =.748), presence and absence of venous invasion (P =.927), and mitotic rate (P =.159). Nuclear pleomorphism and necrosis were not significant factors in prognosis. Flow cytometric DNA analysis of paragangliomas and pheochromocytomas correlated with biological behavior in the patients with regard to metastasis and overall survival in the patients.

Overall survival in advanced breast cancer: relevance of progesterone receptor expression and DNA ploidy in fine-needle aspirates of 392 patients.

Fine-needle aspiration cytology (FNAC) is essential for making a diagnosis in advanced breast cancer. The determination of hormone receptors in the material obtained is useful for predicting patient response to endocrine therapy, but the prognostic value of hormone receptor expression as well as the clinical utility of DNA flow cytometry are controversial. The aim of this prospective study with long-term follow-up (median: 81 months) was to evaluate these biomarkers in relation to overall survival in a series of 392 patients with advanced breast cancer (stage IIB, n=106; IIIA, n=66; IIIB, n=174; and IV, n=46) using FNAC. Estrogen and progesterone receptor expression was found in 65.1% and 46.1% of the tumors, respectively. Hormone receptors were not found to be associated with clinical staging. DNA aneuploidy was present in 70.9% of the cases and the median S-phase fraction (SPF) was 9.4%. There was a significant correlation of aneuploidy and high SPF with lack of hormone receptors. In univariate analysis, advanced disease stage, absence of hormone receptors, DNA aneuploidy and high SPF showed a statistically significant correlation with poor clinical outcome. In multivariate analysis, disease stage, progesterone receptors and DNA ploidy retained independent prognostic significance in relation to overall survival. These data indicate that progesterone receptor expression and DNA ploidy are independent prognostic factors in advanced breast cancer.

Overall survival in advanced breast cancer: Relevance of progesterone receptor expression and DNA ploidy in fine-needle aspirates of 392 patients

Fine-needle aspiration cytology (FNAC) is essential for making a diagnosis in advanced breast cancer. The determination of hormone receptors in the material obtained is useful for predicting patient response to endocrine therapy, but the prognostic value of hormone receptor expression as well as the clinical utility of DNA flow cytometry are controversial. The aim of this prospective study with long-term follow-up (median: 81 months) was to evaluate these biomarkers in relation to overall survival in a series of 392 patients with advanced breast cancer (stage IIB, n=106; IIIA, n=66; IIIB, n=174; and IV, n=46) using FNAC. Estrogen and progesterone receptor expression was found in 65.1% and 46.1% of the tumors, respectively. Hormone receptors were not found to be associated with clinical staging. DNA aneuploidy was present in 70.9% of the cases and the median S-phase fraction (SPF) was 9.4%. There was a significant correlation of aneuploidy and high SPF with lack of hormone receptors. In univariate analysis, advanced disease stage, absence of hormone receptors, DNA aneuploidy and high SPF showed a statistically significant correlation with poor clinical outcome. In multivariate analysis, disease stage, progesterone receptors and DNA ploidy retained independent prognostic significance in relation to overall survival. These data indicate that progesterone receptor expression and DNA ploidy are independent prognostic factors in advanced breast cancer.

Racial differences in genetic factors associated with breast cancer.

Breast cancer in African Americans in the US is more aggressive and has a worse outcome than breast cancer in Caucasians. Although the incidence of breast cancer among US whites is higher than among blacks, the mortality rates for blacks are much higher. Breast cancer in blacks is also associated with a more advanced stage at presentation and pathologically aggressive tumors commonly exhibiting estrogen receptor negativity, higher S-phase fractions, and higher numbers of involved lymph nodes. This paper reviews some of the genetic factors that have been shown to be associated with a difference in breast cancer outcome between African Americans and Caucasians in the US such as the BRCA1 and BRCA2 genes, p53 mutations, UGT1A1 gene polymorphisms, and HER-2/neu gene amplifications/overexpression.

DNA ploidy and S-phase fraction, but not p53 or NM23-H1 expression, predict outcome in colorectal cancer patients. Result of a 5-year prospective study.

The aim of this study was to determine TP53 and NM23-H1 immunoreactivity, DNA ploidy, and S-phase fraction (SPF) in a series of 160 patients undergoing resective surgery for primary operable colorectal cancer (CRC) and to establish whether these alterations have any clinical value in predicting CRC patients' prognosis. TP53 and NM23-H1 expressions were evaluated on paraffin-embedded tissue by immunohistochemistry and DNA-ploidy and SPF on frozen tissue by flow-cytometric analysis. The median follow-up time in our study group was 71 months (range 34-115 months). P53 protein expression was associated with distal tumors (P<0.05) and DNA aneuploid tumors (P<0.05) tumors. DNA-aneuploidy was associated with distal tumors (P<0.01), histological grade (G3) (P<0.05), advanced Dukes' stage (C and D) (P<0.01), lymph node metastases (P<0.01) and high SPF (>18.3%) (P<0.01). The major significant predictors for both disease relapse and death were advanced Dukes' stage, DNA-aneuploidy, and high SPF, while lymphohematic invasion was the only independent factor for relapse and non-curative resection for death. Our results indicate that DNA aneuploidy and high SPF are associated in CRC with a poor clinical 5-year outcome, while in contrast the prognostic role of TP53 and NM23-H1 expression is still to be clarified.

Specific codon 13 K-ras mutations are predictive of clinical outcome in colorectal cancer patients, whereas codon 12 K-ras mutations are associated with mucinous histotype

BackgroundK-ras mutations, one of the earliest events observed in colorectal carcinogenesis, are mostly found in codons 12 and 13, and less frequently in codon 61, all three of which are estimated to be critical for the biological activity of the protein. Nevertheless the prognostic significance of such mutations remains controversial. Our purpose was to assess whether any or specific K-ras mutations in primary colorectal cancer had prognostic significance and were linked to clinico-pathological parameters. Patients and methodsPaired tumor and normal tissue samples from a consecutive series of 160 untreated patients (median of follow up 71 months), undergoing resective surgery for primary colorectal carcinoma, were prospectively studied for K-ras mutations by PCR/single strand conformation polymorphism sequencing. ResultsSeventy-four of the 160 (46%) primary colorectal carcinomas presented mutations in K-ras: 54% in codon 12, 42% in codon 13 (particularly G→A transition) and 4% in both. Codon 12 K-ras mutations were associated with mucinous histotype (P <0.01), while codon 13 K-ras mutations were associated with advanced Dukes’ stage (P <0.05), lymph-node metastasis (P <0.05) and high S-phase fraction (P <0.05). Multivariate analysis showed that codon 13 K-ras mutations, but not any mutation, were independently related to risk of relapse or death. ConclusionsOur results suggest that codon 12 K-ras mutations may have a role in the mucinous differentiation pathway, while codon 13 mutations have biological relevance in terms of colorectal cancer clinical outcome.