Sorted patterned ground: new appalachian localities South of the glacial border.

Sorted stripes, nets, and polygons in the Appalachians of Pennsylvania, West Virginia, and Virginia display patterns and stone orientations visibly similar to those of ground patterned under current cold climates. Larger forms appear inactive or fossil and may provide data on the paleoclimate and slope stability.

Frequency discrimination following the selective destruction of cochlear inner and outer hair cells.

Frequency discrimination was measured behaviorally before and after drug-induced lesions of cochlear hair cells in the cat. Discrimination was unaffected by complete loss of outer hair cells provided that at least 50% of inner hair cells were intact. Thus, inner hair cells are important for frequency discrimination, and they can function normally in this regard without the influence of outer hair cells.

Two-component hearing sensations produced by two-electrode stimulation in the cochlea of a deaf patient.

Dissimilarities in perception elicited by stimulation with two electrodes were estimated. A two-dimensional spatial configuration was found to be suitable to represent the dissimilarity data, and the two dimensions could be interpreted as corresponding to the position of the apical and basal electrode of the two-electrode combination. A speech-processing strategy that converts acoustic, first and second formants to two-electrode stimulation is proposed.

Human breast cancer: correlation of relapse and survival with amplification of the HER-2/neu oncogene.

The HER-2/neu oncogene is a member of the erbB-like oncogene family, and is related to, but distinct from, the epidermal growth factor receptor. This gene has been shown to be amplified in human breast cancer cell lines. In the current study, alterations of the gene in 189 primary human breast cancers were investigated. HER-2/neu was found to be amplified from 2- to greater than 20-fold in 30% of the tumors. Correlation of gene amplification with several disease parameters was evaluated. Amplification of the HER-2/neu gene was a significant predictor of both overall survival and time to relapse in patients with breast cancer. It retained its significance even when adjustments were made for other known prognostic factors. Moreover, HER-2/neu amplification had greater prognostic value than most currently used prognostic factors, including hormonal-receptor status, in lymph node-positive disease. These data indicate that this gene may play a role in the biologic behavior and/or pathogenesis of human breast cancer.

3D finite element analyses of insertion of the Nucleus standard straight and the Contour electrode arrays into the human cochlea.

Previous experimental studies of insertion of the Nucleus standard straight and the Contour arrays into the scala tympani have reported that the electrode arrays cause damage to various cochlear structures. However, the level of insertion-induced damage by these electrode arrays to cochlear structures (the spiral ligament, the basilar membrane and the osseous spiral lamina) has not been quantified. Although it has been suggested that rotation can overcome this resistance and prevent the basilar membrane from being pierced by the tip of the Nucleus standard straight array, there has not been any attempt to study the relationship between the rotation and the reduction of damage to the basilar membrane. In this study, 3D finite element analyses of insertions of the Nucleus standard straight array and the Contour array into the scala tympani have been undertaken. The perforation of the basilar membrane by the tip of the Nucleus standard straight array at the region of 11-14 mm from the round window appears to be compounded by the geometry of the spiral passage of the scala tympani. Anti-clockwise rotations between 25 degrees and 90 degrees applied at the basal end of the electrode array (for the right cochlea) were shown to significantly reduce the contact stresses exerted by the tip on the basilar membrane which support the practice of applying small rotation partway through insertion of electrode array to minimize damage to the basilar membrane. Although the Contour array (with its stylet intact) is stiffer than the Nucleus standard straight array, a slight withdrawal of the stylet from the Contour array before insertion was found to significantly reduce damage by the electrode array to the spiral ligament and the basilar membrane.

Hormone receptor status of a contralateral breast cancer is independent of the receptor status of the first primary in patients not receiving adjuvant tamoxifen.

PURPOSE: To determine whether the hormone receptor status of the primary breast cancer (PBC) is predictive of the hormone receptor status of the subsequent contralateral breast cancer (CBC). PATIENTS AND METHODS: We identified patients in our database with known estrogen receptor (ER; n = 193) and/or progesterone receptor (PgR; n = 178) status in their PBC and in their subsequent CBC. One hundred twenty-six of these patients had received no adjuvant therapy, 34 had received adjuvant tamoxifen, and 33 had received adjuvant chemotherapy alone. The median interval between the first diagnosis of PBC and the development of the subsequent CBC was 3 years. ER and PgR assays were assessed biochemically in two central reference laboratories using identical quality-controlled ligand-binding methods. RESULTS: Among systemically untreated patients (n = 126), 88% of patients with ER-positive PBC and 75% of patients with ER-negative PBC developed an ER-positive CBC (P = .11). Among the tamoxifen-treated patients, those with an ER-positive PBC were almost equally likely to develop an ER-positive (47%) or ER-negative (53%) CBC (P = .99). PgR status was similar. In the untreated group (n = 112), 59% of patients with a PgR-positive PBC and 66% with a PgR-negative PBC developed a PgR-positive CBC (P = .48). Among tamoxifen-treated patients (n = 33), 50% of patients with a PgR-positive PBC versus 27% of patients with a PgR-negative PBC developed a PgR-positive CBC (P = .28). CONCLUSION: ER and PgR status of the primary tumor does not predict the hormone receptor status of the subsequent CBC in the absence of selective pressure of adjuvant therapy. Thus, other reasons should be considered to clarify the failure of tamoxifen to reduce the incidence of CBC in patients with a receptor-negative PBC.

Tumor characteristics and clinical outcome of elderly women with breast cancer.

BACKGROUND: The number of elderly patients with breast cancer is increasing. Limited age-related information available about this disease prompted this study. PATIENTS AND METHODS: The study population was derived from 50828 and 256287 patients with invasive breast cancer in San Antonio breast cancer databases and the Surveillance, Epidemiology, and End Results (SEER) registry, respectively. Tumor biologic and clinical characteristics, local and systemic therapies, and survival according to the patient's age were analyzed. Survival was also compared with that of age-matched women from the general population. RESULTS: In patients 55 years old or older, there was an association between increasing age at diagnosis and the presence of more favorable biologic characteristics of the tumor, including more tumors that express steroid receptors, lower proliferative rates, diploidy, normal p53, and absence of the expression of epidermal growth factor receptor and c-erbB2. In older patients with lymph node-negative disease and/or small tumors, the observed and expected survivals were almost identical. In the SEER registry, the 8-year survival of lymph node-negative patients relative to the expected survival of age-matched women from the general population was 1.01 (95% confidence interval [CI] = 0.98-1. 04) for patients 70-74 years old, 1.06 (95% CI = 1.01-1.11) for patients 75-79 years old, and 1.09 (95% CI = 0.98-1.20) for patients 80-84 years old. CONCLUSION: In women 55 years old or older, advancing age is associated with more favorable tumor biology, and breast cancer survival in older women is similar to survival in the general population irrespective of disease status. This favorable outcome should be considered when making clinical decisions in older patients.

Breast cancer prognosis in a mixed Caucasian-Hispanic population.

Prognostic factors were compared between 1,249 Caucasian and 360 Hispanic women with breast cancer. A significantly greater proportion of Hispanic women were less than 50 years of age at diagnosis compared to Caucasian women (P less than .0001). Significantly more Hispanic women presented with tumors larger than 3 cm in diameter and with positive axillary lymph nodes than did Caucasian women (P = .004 and P = .0001, respectively). Significantly more Hispanic women were estrogen receptor (ER) negative (P = .005). However, when examined by age groups, the relationships between ethnicity and extent of disease and ER status were observed only among women over 50 years of age. Multivariate analyses demonstrated that there was no difference in survival between Caucasian and Hispanic women once adjustments were made for the number of positive lymph nodes and ER status. Although complete data were not available, it appeared that the incidence of breast cancer is lower in this population of Hispanic women than in Caucasian women.

Prediction of axillary lymph node status in breast cancer patients by use of prognostic indicators.

BACKGROUND: If axillary lymph node status of breast cancer patients could be accurately predicted from basic clinical information and from characteristics of their primary tumors, then many patients could be spared axillary lymph node dissection. Tumor size alone does not allow the identification of groups with very low or high risk of being axillary node positive. PURPOSE: Our goal was to investigate the possibility of using prognostic indicators to predict axillary node status of patients with primary breast cancer. METHODS: Data from 26,683 patients from the National Breast Cancer Tissue Resource were used in this study. Patients in this dataset were randomly assigned to a training set (patient information used to construct predictive models) or a validation set (patient information used to prospectively evaluate predictive models). The records of a total of 11,964 case patients that had complete prognostic factors and pathologic data were analyzed: 5963 patients in the training set and 6001 patients in the validation set. All of the patients studied had tumors 5 cm or less in size and at least 15 axillary lymph nodes that had been examined. Data used for construction of the predictive models were available for all patients and included tumor size, number of nodes positive, patient age, quantitative estrogen receptor levels, quantitative progesterone receptor (PgR) levels, DNA flow cytometry-derived ploidy, and S-phase fraction. Logistic regression models were used to predict nodal status. RESULTS: Multivariate predictive models were produced that used tumor size, patient age, S phase, and PgR as independent predictors. These models allowed identification of patient risks of being node positive ranging from 6%-79% and as having 10 or more positive nodes ranging from less than 1% to slightly more than 30%. CONCLUSION: Addition of prognostic indicator information to tumor size can refine estimates of whether a patient is likely to be node positive. However, no patient subsets could be identified as having greater than 95% chance of being node negative or node positive. IMPLICATIONS: These predictive models cannot alleviate the necessity of axillary node dissection for staging of breast cancer patients in situations in which nodal status would affect therapeutic decisions. Subsets of patients could be identified who had a less than 5% chance of having 10 or more positive nodes. Thus, some patients could be spared axillary dissection if it was being performed solely to identify patients with this high-risk feature.

Tumor biologic factors and breast cancer prognosis among white, Hispanic, and black women in the United States.

BACKGROUND: In the United States, prognosis and survival after the diagnosis of breast cancer is poorer among black patients and, to a lesser extent, among Hispanic patients, compared with white patients. Patients who are black or Hispanic have been reported to present with higher stage or more advanced disease. Even after adjusting for stage, however, survival rates are lower for blacks but not for Hispanics. PURPOSE: Our purpose was to compare survival, age, tumor size, nodal status, estrogen-receptor (ER) and progesterone-receptor (PgR) status, histologic type, S-phase fraction, DNA ploidy status, HER-2/neu protein expression, and p53 protein status, along with systemic treatment, in a large group of white, black, and Hispanic U.S. women. METHODS: From 1970 to 1991, breast tumor specimens were submitted to The University of Texas Health Science Center from 31 contributing hospitals throughout the United States for ER and PgR assay. A total of 4885 white, 1016 black, and 777 Hispanic women were eligible for this study. Median follow-up was 57 months. RESULTS: Overall, white women were significantly more likely to be older and to have smaller tumors, have less lymph node involvement, have tumors with positive ER and PgR status, and have a lower S-phase fraction compared with Hispanic or black women. There were no clinically important differences in DNA ploidy, histologic type, HER-2/neu, and p53 expression among the three groups. Considering all stages, white women had the best overall survival (date of diagnosis to date of death) at 5 years--75% +/- 1% (means +/- SE), with a median survival of 166 months, but Hispanic women had an intermediate survival--70% +/- 2% (median survival, 156 months), and black women had the worst survival--65% +/- 2% (median survival, 117 months) (P < .0001). For node-negative patients, there was no significant difference in disease-free survival (date of diagnosis to date of first recurrence) or overall survival, although blacks tended to have a worse prognosis. For node-positive or locally advanced disease and for metastatic disease, blacks had significantly (P < .0001) worse disease-free and overall survival than did white or Hispanic women. Differences in the use of systemic therapy did not explain these outcomes. CONCLUSION: A number of biologic factors associated with poor prognosis are found with a significantly increased frequency in breast tumors from Hispanic and, particularly, from black women. Tumors with a more aggressive biology could lead to a higher stage at diagnosis and a poorer survival for the group as a whole.

Telomerase activity and survival of patients with node-positive breast cancer.

BACKGROUND: Shortening of telomeres (specialized structures at the ends of chromosomes) beyond a certain length may signal a cell to stop dividing and to enter senescence. A ribonucleoprotein enzyme, telomerase, is a key component in maintaining telomere length. Because the majority of cancers express telomerase but most normal somatic tissues do not, we measured the level of telomerase expression in primary breast cancer specimens for correlation with traditional prognostic indicators and disease outcome. METHODS: Telomerase activity was measured in frozen human breast cancer specimens by use of the Telomeric Repeat Amplification Protocol (TRAP) assay. The level of telomerase activity was expressed as total product generated (TPG) and was corrected for specimen cellularity by expressing it as a ratio of TPG to the sample's 28S ribosomal RNA content. RESULTS: A preliminary study of 150 breast cancer specimens demonstrated that telomerase activity correlated with the fraction of cells in S phase of the cell cycle (r(sp) = .23). In a larger prognostic study of 398 tumors from patients with lymph node-positive breast cancer, telomerase expression correlated with S-phase fraction, progesterone receptor level, DNA ploidy, and lymph node status. After correcting for sample cellularity, increasing TPG levels were associated with decreased disease-free survival (P = .041) and overall survival (P = .009) of the patients. The telomerase activity level remained strongly predictive of death (P = .027) and marginally predictive of disease recurrence (P = .08) after adjustment for other prognostic factors. All P values are two-sided. CONCLUSIONS: Telomerase activity in human breast cancers is associated with a more aggressive tumor phenotype in patients.

Analysis of loss of heterozygosity in 399 premalignant breast lesions at 15 genetic loci.

BACKGROUND: Usual ductal hyperplasia (UDH), atypical ductal hyperplasia (ADH), and ductal carcinoma in situ (DCIS) are risk factors for invasive breast cancer (IBC), suggesting that these lesions may be direct precursors of IBC. To identify genetic changes that may be important in the early development of precursor lesions and their progression to malignant or invasive disease, we examined 399 putative precursors (211 UDH, 51 ADH, 81 non-comedo DCIS, and 56 comedo DCIS) for loss of heterozygosity (LOH) at 15 polymorphic genetic loci known to exhibit high rates of loss in IBC. We also assessed the sharing of LOH by putative precursors and synchronous cancers. METHODS: The polymerase chain reaction was used to analyze DNA from microdissected archival specimens. RESULTS AND CONCLUSIONS: In hyperplasias from noncancerous breasts (i.e., without DCIS and/or IBC in analyses of hyperplasias), LOH at any given locus was rare (range, 0%-15%), although 37% of UDH and 42% of ADH lesions showed loss for at least one locus, suggesting that the development of hyperplasias can involve many different tumor suppressor genes. In DCIS from noncancerous breasts (i.e., without IBC in analyses of DCIS), LOH was common, with 70% of noncomedo lesions and 79% of comedo lesions showing at least one loss. In DCIS, substantial rates of loss (up to 37%) were observed at loci on chromosomes 16q, 17p, and 17q, suggesting that inactivated tumor suppressor genes in these regions may be important in the development of noninvasive breast cancer. When DCIS lesions from cancerous and noncancerous breasts were compared, substantially more LOH was observed in the cancerous breasts at a few loci (on chromosomes 2p, 11p, and 17q), suggesting that genetic alterations in these regions may be important in the progression to invasive disease. Among specimens harvested from cancerous breasts, 37% of UDH, 45% of ADH, 77% of noncomedo DCIS, and 80% of comedo DCIS lesions shared LOH with synchronous cancers at one locus or more, supporting the idea that the putative precursors and the cancers are genetically related.

Distribution of 17 beta-estradiol in the sera of normal British and Japanese women.

Normal Japanese women had significantly more of their blood 17 beta-estradiol (E2) bound to sex hormone-binding globulin (SHBG) (53%) than British women (30%) and conversely less bound to albumin. While the proportion of SHBG-bound E2 increased with SHBG capacity and while binding fell as weight increased, the differences between the races do not appear to be explicable in terms of SHBG capacity or weight. At a given SHBG capacity, the Japanese women had more E2 bound to the protein than the British women. Where weights in the 2 populations overlapped, the Japanese women still had more of their E2 bound to SHBG than did the British women. Our results suggested that the affinity of albumin for E2 is lower in Japanese women.

Selection of cancer chemotherapy for a patient by an in vitro assay versus a clinician.

One hundred thirty-three patients with advanced metastatic cancer were randomized to receive single-agent chemotherapy selected by either a medical oncologist or an in vitro capillary cloning system. Thirty-six of the 65 patients (55%) who were randomly assigned to selection of a drug by the clinician actually received a drug; these patients were able to be evaluated for clinical response. Of these 36 patients, one had a partial tumor response (3%). Only 19 of the 68 patients (28%) who were randomly assigned to selection of a drug by the capillary system actually received a drug; these patients were able to be evaluated for clinical response. Of these 19 patients, four (21%) had partial tumor responses. In the assessable patients (36 in the clinician's choice group, 19 in the capillary cloning group), the partial response rate was superior for drug selection by the capillary cloning system (P = .04). For all patients randomly assigned to a group (65 in the clinician's choice group, 68 in the capillary cloning group), the response rate was not significantly different (1.5% and 5.9%, respectively; P = .37). When overall survival rates for patients in the two groups were compared, there was no difference. We conclude that drug sensitivity testing in capillary tubes can improve the response rate for patients with advanced malignancies. This improved response rate, however, does not translate into improved survival times for these patients.

Evaluation of creatine analogues as a new class of anticancer agents using freshly explanted human tumor cells.

BACKGROUND: The creatine kinase (CK) isozymes and their substrates, creatine and creatine phosphate, are believed to play a pivotal role in energy transduction in tissues with large, fluctuating energy demands, such as skeletal muscle, heart, and brain. This enzyme system may also be involved in the process of cellular transformation. Inhibition of tumor cell growth by creatine analogues has been observed and may be due to the ability of these analogues to impair cellular energy generation and utilization. PURPOSE: An in vitro human tumor colony-forming assay was used to predict the clinical usefulness of creatine analogues as anticancer agents. METHODS: The ability of cyclocreatine (1-carboxymethyl-2-iminoimidazolidine) and homocyclocreatine (1-carboxyethyl-2-iminoimidazolidine) to inhibit the growth of cells prepared from tumor samples taken directly from patients was evaluated by quantitative measurement of colony formation in a soft-agar cell culture assay system. Cyclocreatine was tested in this human tumor colony-forming assay at concentrations ranging from 0.067 to 20 mM against 128 tumor samples, 51 of which formed colonies in the assay and were considered evaluable. Homocyclocreatine was similarly tested at concentrations from 0.2 to 20 mM against 139 tumor samples; 54 were considered evaluable. The colony-forming assay was also used to compare the efficacy of the creatine analogues to representatives from the six major classes of standard chemotherapeutics (alkylating agents, antimetabolites, DNA intercalators, platinum compounds, topoisomerase inhibitors, and tubulin-interacting agents). In addition, CK levels were measured in 192 tumor samples that were taken from 166 patients. RESULTS: Cyclocreatine and homocyclocreatine, at concentrations previously achieved in animal tissues (7-20 mM), had antitumor activity against 19% and 50%, respectively, of tumor samples that formed colonies in the assay. Cyclocreatine was effective against a subset of tumors sensitive to homocyclocreatine (P = .023; Fisher's exact test), which was the more potent creatine analogue in this assay (P < .001; McNemar's test). No relationships were seen between tumor samples sensitive to the creatine analogues and those sensitive to standard chemotherapeutics. Pairwise Wilcoxon rank sum tests indicated that CK activity was significantly higher in tumors with any growth in the colony assay compared with tumors that did not grow (P < .025). CONCLUSIONS: The creatine analogues, cyclocreatine and homocyclocreatine, effectively reduced colony formation of freshly explanted human tumor cells. The mechanism of action or resistance to these compounds seems to differ from those of standard chemotherapeutics. IMPLICATIONS: Creatine analogues that may alter the energy status of the tumor cell potentially represent promising new anticancer agents that function through a unique mechanism.

Activity of intoplicine (RP60475), a new DNA topoisomerase I and II inhibitor, against human tumor colony-forming units in vitro.

BACKGROUND: Intoplicine (RP60475) is the most active analogue evaluated in the 7H-benzo[e]-pyrido-[4,3-b]-indole series of antineoplastic compounds. It exerts its activity through inhibition of DNA topoisomerase I and II. PURPOSE: This study was planned to determine plasma concentrations of intoplicine necessary for optimal clinical antitumor activity, as well as to pinpoint possible responsive tumor types that can be included in phase II clinical studies. METHODS: Tumor specimens were collected from patients as part of routine clinical measures. Single-cell suspensions were prepared from freshly obtained solid tumor biopsy specimens and were exposed to intoplicine either for 1 hour or continuously. The sensitivity of these specimens to intoplicine was evaluated in a human tumor soft-agar cloning assay. Response was considered positive when the colony-forming unit count in drug-treated samples was 50% or less than the response of control tumor samples treated with saline. RESULTS: With 1-hour exposure to intoplicine at final concentrations of 2.5 micrograms/mL and 10.0 micrograms/mL, 26% and 54% of the assessable specimens showed positive in vitro responses, respectively. With continuous exposure to intoplicine at concentrations of 0.25 micrograms/mL and 2.5 micrograms/mL, 16% and 71% of the assessable specimens showed positive responses, respectively. Activity was seen against breast (71%), non-small-cell lung (69%), and ovarian (45%) cancer colony-forming units at a intoplicine concentration of 10.0 micrograms/mL after 1-hour exposure. Incomplete cross-resistance with doxorubicin, cisplatin, fluorouracil, 4-hydroperoxycyclophosphamide, vinblastine, and etoposide was also observed. CONCLUSIONS: Intoplicine appears to be active in vitro against a variety of human tumors, including a subgroup of tumors insensitive in vitro to standard antineoplastic compounds. If plasma levels of 10.0 micrograms/mL can be achieved in subjects in ongoing clinical trials, intoplicine could have significant clinical activity. IMPLICATIONS: These data indicate that further investigation of intoplicine is warranted.

Loss of heterozygosity at D14S62 and metastatic potential of breast cancer.

BACKGROUND: In breast cancer progression, the prevalence of damage at specific genetic loci often increases with the stage of the lesion (i.e., from noninvasive to invasive to metastatic). By use of genetic markers and analysis of allelic imbalances (loss of heterozygosity [LOH]) to compare DNA samples from paired normal and breast tumor tissues, we examined whether specific genetic changes in primary breast cancers can serve as biomarkers of metastatic potential. METHODS: DNA samples from 76 patients with primary breast cancer (42 with axillary lymph node-negative disease and 34 with axillary lymph node-positive disease) were genotyped with four genetic markers spanning chromosome 14q31-q32. The intensity ratios of the two genetic alleles in normal-tumor DNA pairs were examined in genetically informative individuals. LOH was scored when the tumor allele intensity ratio (tumor allele 1/tumor allele 2) divided by the normal allele intensity ratio (normal allele 1/normal allele 2) was either less than 0.71 (tumor allele 1 LOH) or greater than 1. 4 (tumor allele 2 LOH). RESULTS/CONCLUSIONS: Contrary to our expectations, we found statistically significantly more LOH events at markers D14S62 (two-sided P =.001) and D14S51 (two-sided P =.02) in primary breast cancers from patients with lymph node-negative disease versus lymph node-positive disease, suggesting the presence of a gene in this region that affects metastatic potential. Analysis of small interstitial or terminal deletions in the tumors of six especially informative patients with lymph node-negative disease places the putative metastasis-related gene in a 1490-kilobase region near D14S62. IMPLICATIONS: LOH in the D14S62 region may impede the process of metastasis. Therefore, the D14S62 region LOH profile may have prognostic implications, and the isolation of the metastasis-related gene(s) in this region may lead to better diagnosis and treatment of breast cancer.

Association of p53 protein expression with tumor cell proliferation rate and clinical outcome in node-negative breast cancer.

BACKGROUND: The p53 (also known as TP53) tumor suppressor gene encodes for a nuclear phosphoprotein thought to regulate proliferation of normal cells. Most p53 mutations result in a nonfunctional protein that accumulates in tumor cell nuclei. These common mutations appear to be involved in the development and/or progression of several neoplastic diseases including human breast cancer. PURPOSE: Our purpose was to investigate the relationships between levels of mutant p53 protein expression, tumor cell proliferation rate, and clinical outcome in patients with node-negative breast cancer. METHODS: Expression of mutant p53 protein was evaluated by frozen-section immunohistochemistry (IHC) and light microscopy in 700 breast cancers from axillary lymph node-negative patients with long-term follow-up (median, 54 months). The immunostaining signal was expressed as the sum of scores representing the proportion and staining intensity of negative and positive tumor cell nuclei (ranges, 0 and 2-8, respectively). Statistical comparisons were made between levels of p53 protein expression and disease-free survival, overall survival, and tumor proliferation rate expressed as the percentage of cells in the S phase (%S phase) as determined by flow cytometry. RESULTS: Of the 700 tumors, 362 (52%) showed positive nuclear immunostaining (IHC score > 0). Proliferation rates were significantly higher (P = .0001) in positive tumors (median %S phase, 7.1%) than in negative tumors (4.1%). In a univariate cutpoint analysis, negative tumors (n = 388) versus low-positive tumors (IHC score = 2-6; n = 263) versus high-positive tumors (IHC score > 6; n = 99) showed progressively reduced disease-free survival (80% versus 72% versus 58% at 5 years, respectively; P < or = .05 for all pairwise comparisons). Analogous results for overall survival were 88% versus 84% versus 74%; only the result for negative versus high positive tumors was significant (P = .003). In a multivariate analysis, expression of p53 protein and high %S phase were independently associated with reduced disease-free survival (P = .008 and .01, respectively). CONCLUSIONS: Expression of mutant p53 protein was associated with high tumor proliferation rate, early disease recurrence, and early death in node-negative breast cancer. Despite the strong direct correlation between accumulation of p53 protein and tumor proliferation rate, both factors were independently associated with poor prognosis, suggesting that p53 may have other biological functions in addition to cell-cycle regulation. IMPLICATIONS: This test, when combined with other prognostic factors, may enhance our ability to identify node-negative breast cancer patients at high risk for early disease recurrence and/or death, for whom the use of adjuvant chemotherapy is unequivocally justified.

Heat shock protein hsp70 in patients with axillary lymph node-negative breast cancer: prognostic implications.

BACKGROUND: Cell synthesis of heat shock (stress-response) proteins is increased by a variety of environmental and pathophysiological stressful conditions. The 70-kd heat shock protein (hsp70) is thought to be involved in protein-protein interactions including those of the protein products of the human c-myc oncogene and the p53 (also known as TP53) tumor suppressor gene. PURPOSE: The purpose of this study was to investigate whether elevated hsp70 expression may be an indicator of biological stress experienced by a breast cancer and may, therefore, predict disease outcome. METHODS: Levels of hsp70 were determined by Western blot analysis in primary breast tumors from patients with negative axillary lymph nodes. We performed exploratory data analyses on a set of 162 primary breast cancers and constructed prognostic indexes of hsp70 expression levels. The optimal cutpoint for hsp70 expression was considered to be the value yielding the greatest separation for disease-free survival for the resulting two groups of patients. That cutpoint was then validated in a set of 345 tumors by univariate and multivariate analyses. Data were analyzed for overall survival, disease-free survival, tumor size, and patient age, as well as estrogen receptor and progesterone receptor status, ploidy (DNA content), and percentage of cells in S phase as determined by flow cytometry. RESULTS: Expression of hsp70 emerged as a useful prognostic factor, both in univariate and in multivariate analyses. Patients whose tumors had high expression of hsp70 had significantly shorter disease-free survival (P = .006). The other statistically significant factors were S-phase fraction (P = .008) and tumor size (P = .01). For patients who received adjuvant therapy, hsp70 was the only independent predictor of disease recurrence (P = .05). For those with tumors 1-3 cm in diameter, hsp70 (P = .008) and S-phase fraction (P = .02) were statistically significant predictors of recurrence. CONCLUSIONS: Measurement of hsp70 expression in primary tumors from patients with node-negative breast cancer may be useful in identifying patients at high risk for disease recurrence and thus may affect decisions regarding treatment after surgery. IMPLICATIONS: Future studies should be performed to determine if detection of hsp70 by immunohistochemistry can be used to predict clinical outcome and to better understand the relationships between hsp70 and the effects of various treatment modalities.

Activity of DMP 840, a new bis-naphthalimide, on primary human tumor colony-forming units.

BACKGROUND: DMP 840 ((R,R)-2,2'-[1,2-ethanediylbis[imino(1-methyl-2,1-ethanediyl)]]- bis[5-nitro-1H-benz[de]-iso[quinoline-1,3(2H)-dione]dimethane- sulfonate; NSC-D640430) is one in a series of bis-naphthalimides that binds DNA with high affinity and has sequence specificity to multiple G and C bases. It is also a potent inhibitor of RNA synthesis. DMP 840 has been selected for clinical evaluation on the basis of a broad spectrum of activity (including cures) in human tumors in murine models. PURPOSE: We evaluated DMP 840 in a human tumor clonogenic assay to estimate what plasma concentrations may be necessary for clinical cytotoxic activity and to determine what types of tumors potentially might be primary targets for initial phase II studies. METHODS: A soft-agar cloning system assay was used to determine the in vitro effects of DMP 840 against cells from biopsy specimens of colorectal, breast, lung ovarian, renal cell, stomach, and bladder cancers and from other tumor types. A total of 260 human tumor specimens were exposed continuously during the assay to DMP 840; 103 were assessable (20 colonies or more on control plates and 30% or less survival for the positive control). An in vitro response was defined as at least a 50% decrease in tumor colony formation resulting from drug exposure compared with controls. RESULTS: In vitro responses were seen in 10% (one of 10), 54% (55 of 101), 80% (82 of 103), and 89% (82 of 92) of specimens tested at 0.01, 0.1, 1.0, and 10.0 micrograms/mL of DMP 840, respectively. At a concentration of 0.1 microgram/mL, specific activity was seen against melanoma (80%) and against renal cell (80%), ovarian (63%), breast (54%), non-small-cell lung (42%), and colorectal cancers (33%). DMP 840 demonstrated activity in tumor specimens resistant in vitro to methotrexate (88%), doxorubicin (58%), platinum (57%), cyclophosphamide (53%), vinblastine (53%), etoposide (53%), fluorouracil (37%), and paclitaxel (36%). CONCLUSIONS: At in vitro concentrations of 0.1 microgram/mL as a continuous exposure, DMP 840 has activity against a variety of human tumors, including a subgroup resistant in vitro to standard antineoplastic agents. IMPLICATIONS: Further clinical development of DMP 840 is warranted.