Preoperative Echocardiographic Indices of Diastolic Dysfunction and Brain Natriuretic Peptide in Predicting Postoperative Atrial Fibrillation After Noncardiac Surgery.

BACKGROUND: We have shown previously that either echocardiographic indices of diastolic dysfunction or increased preoperative brain natriuretic peptide (BNP) predict postoperative atrial fibrillation (POAF). Because these 2 predictors of POAF have not been evaluated together, our goal was to further elucidate their concurrent role in patients undergoing noncardiac thoracic surgery. METHODS: We retrospectively identified 191 patients who had a preoperative transthoracic echocardiogram and serum BNP level collected as part of routine care before major lung or esophageal resection. Clinical and echocardiographic data were compared between patients who did or did not develop POAF (>5 minutes), and prognostic factors for POAF were identified. RESULTS: Univariate associations with POAF (41 of 191; 22% patients) included older age (P = .04), male sex (P = .01), hypertension (P = .03), increased body mass index (P = .01), and prolonged transmitral flow deceleration time (P < .0001), whereas BNP was not statistically significant (P = .07). Stepwise logistic regression analysis showed that both increasing transmitral flow deceleration time (continuous data log base 2 transformed; odds ratio, 16.05; 95% confidence interval, 3.74-68.96; P = .0002) and left atrial diastolic volume index (continuous data log base 2 transformed; odds ratio, 3.29; 95% confidence interval, 1.22-8.91; P = .02) were independent risk factors of POAF (area under the receiver operating characteristic curve = 0.73). There was no significant interaction between BNP and the 2 independent variables (P = .60, and P = .90), respectively. CONCLUSIONS: In a cohort of patients who had echocardiography and BNP measurements before undergoing major thoracic surgery, this study showed that when evaluated together greater preoperative left atrial diastolic volume index and transmitral flow deceleration time but not BNP levels were independent predictors for POAF.

Continuous Trastuzumab Therapy in Breast Cancer Patients With Asymptomatic Left Ventricular Dysfunction.

BACKGROUND: Adjuvant trastuzumab is a highly effective targeted treatment that improves survival for patients with HER2-positive breast cancer. However, trastuzumab interruption is recommended for patients who develop treatment-induced cardiotoxicity (i.e., decline in left ventricular ejection fraction [LVEF], with or without symptoms) and can lead to an incomplete course of treatment. We studied the cardiac safety of continuous trastuzumab therapy among patients with asymptomatic declines in LVEF. METHODS: We retrospectively evaluated patients with HER2-positive breast cancer treated with adjuvant trastuzumab at our institution between 2005 and 2010. Treatment-induced cardiotoxicity was defined by an absolute decrease in LVEF of ≥10% to below 55% or an absolute decrease of ≥16%. Logistic regression was used to determine the association between candidate risk factors and treatment-induced cardiotoxicity. RESULTS: Among 573 patients, 92 (16%) developed treatment-induced cardiotoxicity. Trastuzumab was continued without interruption in 31 of 92 patients with treatment-induced cardiotoxicity­all were asymptomatic with LVEF of ≥50% at cardiotoxicity diagnosis with median LVEF of 53% (range, 50%-63%), and none developed heart failure during follow-up. Risk factors associated with treatment-induced cardiotoxicity included age (p = .011), anthracycline chemotherapy (p = .002), and lower pretrastuzumab LVEF (p < .001). CONCLUSION: Among patients who develop asymptomatic treatment-induced cardiotoxicity with LVEF of ≥50%, continuous trastuzumab therapy appears to be safe.

Trastuzumab interruption and treatment-induced cardiotoxicity in early HER2-positive breast cancer.

Trastuzumab improves outcomes among patients with HER2-positive breast cancer but is associated with a risk of treatment-induced cardiotoxicity (TIC). It is unclear how frequently TIC leads to trastuzumab interruption outside of prospective trials, and how TIC is managed in clinical practice. Patients with HER2-postive breast cancer receiving adjuvant trastuzumab from 2005 to 2010 were identified (n = 608). We evaluated the incidence, risk factors, and management of trastuzumab interruption due to TIC. In total, 488 (80 %) patients were treated with anthracycline prior to trastuzumab. Trastuzumab was interrupted in 108 (18 %) patients. Cumulative trastuzumab dose was lower in the interrupted group (median 86 vs. 108 mg/kg, p < 0.0001). The most common reason for interruption was TIC (66 of 108 patients): 20 had symptomatic heart failure and 46 had asymptomatic left ventricular ejection fraction (LVEF) decline. Patients with trastuzumab interruption for TIC were older (54 vs. 50 years, p = 0.014) with lower LVEF before anthracycline (63 vs. 67 %, p < 0.0001) and trastuzumab (62 vs. 67 %, p < 0.0001) therapy. Mean LVEF at baseline, TIC diagnosis, and follow-up after trastuzumab interruption was 63, 45, and 55 %, respectively. Thirty-three of 66 patients with TIC were re-challenged with trastuzumab, and five patients had recurrent LVEF decline. In clinical practice, trastuzumab interruption is common and most often due to TIC, with most patients receiving anthracycline prior to trastuzumab. Cardiac dysfunction improves after trastuzumab interruption but may not fully recover to baseline. Strategies to minimize cardiotoxicity and treatment interruption should be investigated to prevent persistent left ventricular dysfunction in affected patients.

Thrombolytic therapy is effective in paroxysmal nocturnal hemoglobinuria: a series of nine patients and a review of the literature.

BACKGROUND: Thrombosis is the major risk factor for death in patients with paroxysmal nocturnal hemoglobinuria. Previous case reports indicate that venous thrombosis in patients with paroxysmal nocturnal hemoglobinuria is amenable to thrombolysis. DESIGN AND METHODS: We reviewed the outcome of thrombolytic therapy for patients with paroxysmal nocturnal hemoglobinuria who had thromboses refractory to anticoagulation at our institutions. RESULTS: In this study of 41 patients who had at least one thrombotic event, we confirmed a very high incidence of recurrence despite anticoagulation. Nine patients with thrombosis were regarded as eligible for administration of intravenous tissue plasminogen activator, which was effective in reversing thrombi in all of 15 occasions in which it was given. Serious hemorrhagic complications developed in three cases. At last follow-up visit, of the nine patients treated, three had died, and six were in very good to excellent condition in terms of clinical outcome and radiological findings. The only patient in whom thrombolysis may have contributed to a fatal outcome also had complications of "heparin induced thrombocytopenia with thrombosis", which we diagnosed in three additional patients. In our review of the literature, nine out of 15 patients treated with thrombolysis have had a good outcome. CONCLUSIONS: Although it is associated with a significant but manageable risk of bleeding, systemic thrombolysis is a highly effective treatment for reversing venous thromboses in patients with paroxysmal nocturnal hemoglobinuria.

CA125 regression in ovarian cancer patients treated with intravenous versus intraperitoneal platinum-based chemotherapy: a gynecologic oncology group study.

OBJECTIVE: CA125 is a non-specific marker of peritoneal irritation which has the potential for false elevation during intraperitoneal treatment. The purpose of this study is to identify the rate of CA125 regression during intraperitoneal (IP) versus intravenous (IV) chemotherapy for ovarian cancer. METHODS: GOG 114, a randomized control trial evaluating IP and IV treatment, includes an intensive CA125 measurement schema with weekly CA125 levels until ≤ 35 units/ml for both IP- and IV-treated patients. Rate of CA125 normalization, median CA125 values for each treatment cycle, as well as clinical and pathologic features were compared between the treatment groups. Baseline CA125 levels and rate of CA125 decline were evaluated with respect to overall survival. RESULTS: CA125 data were available for 223 patients who received IV cisplatin/paclitaxel and for 231 patients who received IV carboplatin followed by IP cisplatin/paclitaxel. Standard prognostic criteria and baseline CA125 values were similar between the treatment groups. For treatment cycles in which IP-treatment was administered, there was no statistically significant difference in CA125 levels between IV- and IP-treated patients. The rate of CA125 normalization was similar between IV- and IP-treated patients (p=0.55). Patients with low pre-chemotherapy CA125 levels which rapidly declined during treatment demonstrated a survival advantage (p<0.0001). CONCLUSIONS: No difference in CA125 decline was identified between IP- and IV-treated patients undergoing a weekly CA125 monitoring schedule. This data supports the utilization of standard CA125 response criteria in the therapeutic monitoring for patients receiving IP treatment.

Identifying clinical improvement in consolidation single-arm phase 2 trials in patients with ovarian cancer in second or greater clinical remission.

OBJECTIVE: Estimates of progression-free survival (PFS) from single-arm phase 2 consolidation/maintenance trials for recurrent ovarian cancer are usually interpreted in the context of historical controls. We illustrate how the duration of second-line therapy (SLT), the time on the investigational therapy (IT), and patient enrollment plan can affect efficacy measures from maintenance trials and might result in underpowered studies. METHODS: Efficacy data from 3 published single-arm consolidation therapies in second remission in ovarian cancer were used for illustration. The studies were designed to show an increase in estimated median PFS from 9 to 13.5 months. We partitioned PFS as the sum of the duration of SLT, treatment-free interval, and duration of IT. We calculated the statistical power when IT is given concurrently with SLT or after SLT by varying the start of IT. We compared the sample sizes required when PFS includes the time on SLT versus PFS that starts after SLT at initiation of IT. RESULTS: Required sample sizes varied with duration of SLT. If IT starts with initiation of SLT, only 34 patients are needed to provide 80% power to detect a 33% hazard reduction. In contrast, 104 patients are required for a single-arm study for 80% power, if IT begins 7.5 months after SLT initiation. CONCLUSIONS: Designs of nonrandomized consolidation trials that aim to prolong PFS must consider the effect of the duration of SLT on the end point definition and on required sample size. If IT is given concurrently with SLT, and after SLT, then SLT duration must be restricted per protocol eligibility, so that a comparison with historical data from other single-arm phase 2 studies is unbiased. If IT is given after SLT, the duration of SLT should be taken into account in the design stage because it will affect statistical power and sample size.

Tumor associated endothelial expression of B7-H3 predicts survival in ovarian carcinomas.

B7-H3 and B7x are members of the B7 family of immune regulatory ligands that are thought to attenuate peripheral immune responses through co-inhibition. Previous studies have correlated their overexpression with poor prognosis and decreased tumor-infiltrating lymphocytes in various carcinomas including uterine endometrioid carcinomas, and mounting evidence supports an immuno-inhibitory role in ovarian cancer prognosis. We sought to examine the expression of B7-H3 and B7x in 103 ovarian borderline tumors and carcinomas and study associations with clinical outcome. Using immunohistochemical tissue microarray analysis on tumor specimens, we found that 93 and 100% of these ovarian tumors express B7-H3 and B7x, respectively, with expression found predominantly on cell membranes and in cytoplasm. In contrast, only scattered B7-H3- and B7x-positive cells were detected in non-neoplastic ovarian tissues. B7-H3 was also expressed in the endothelium of tumor-associated vasculature in 44% of patients, including 78% of patients with high-stage tumors (FIGO stages III and IV), nearly all of which were high-grade serous carcinomas, and 26% of patients with low-stage tumors (FIGO stages I and II; P<0.001), including borderline tumors. Analysis of cumulative survival time and recurrence incidence revealed that carcinomas with B7-H3-positive tumor vasculature were associated with a significantly shorter survival time (P=0.02) and a higher incidence of recurrence (P=0.03). The association between B7-H3-positive tumor vasculature and poor clinical outcome remained significant even when the analysis was limited to the high-stage subgroup. These results show that ovarian borderline tumors and carcinomas aberrantly express B7-H3 and B7x, and that B7-H3-positive tumor vasculature is associated with high-grade serous histological subtype, increased recurrence and reduced survival. B7-H3 expression in tumor vasculature may be a reflection of tumor aggressiveness and has diagnostic and immunotherapeutic implications in ovarian carcinomas.

Multimodality imaging of TGFbeta signaling in breast cancer metastases.

The skeleton is a preferred site for breast cancer metastasis. We have developed a multimodality imaging approach to monitor the transforming growth factor beta (TGFbeta) signaling pathway in bone metastases, sequentially over time in the same animal. As model systems, two MDA-MB-231 breast cancer cells lines with different metastatic tropisms, SCP2 and SCP3, were transduced with constitutive and TGFbeta-inducible reporter genes and were tested in vitro and in living animals. The sites and expansion of metastases were visualized by bioluminescence imaging using a constitutive firefly luciferase reporter, while TGFbeta signaling in metastases was monitored by microPET imaging of HSV1-TK/GFP expression with [(18)F]FEAU and by a more sensitive and cost-effective bioluminescence reporter, based on nonsecreted Gaussia luciferase. Concurrent and sequential imaging of metastases in the same animals provided insight into the location and progression of metastases, and the timing and course of TGFbeta signaling. The anticipated and newly observed differences in the imaging of tumors from two related cell lines have demonstrated that TGFbeta signal transduction pathway activity can be noninvasively imaged with high sensitivity and reproducibility, thereby providing the opportunity for an assessment of novel treatments that target TGFbeta signaling.

Cognitive functions in long-term survivors of ovarian cancer.

BACKGROUND: Women diagnosed with ovarian cancer often undergo chemotherapy involving multiple agents. However, little is known about the incidence of cognitive adverse effects of chemotherapy in survivors of this disease. This cross-sectional study assessed neuropsychological functions in long-term survivors of ovarian cancer who were either in complete remission or with evidence of recurrent disease. METHODS: Forty-eight women diagnosed with ovarian cancer 5 to 10 years prior to study enrollment underwent a brief neuropsychological evaluation; 22 patients were disease free and without history of recurrence (Group 1), and 26 patients had recurrent disease and were receiving treatment with chemotherapy or hormonal therapy (Group 2). RESULTS: There were no statistically significant differences between the two patient groups on tests of attention, memory, and executive functions. Group mean cognitive test scores were within the average range on all tests; however 28% of patients met criteria for cognitive impairment, a significantly higher frequency (p=0.03) than reported in healthy populations. CONCLUSIONS: In this study, neuropsychological test performance did not differ significantly between ovarian cancer survivors who were in remission and patients with recurrent disease and receiving treatment. Cognitive impairment was evident in a subset of patients, although group means test scores were within the average range. Additional research using prospective longitudinal designs is needed to clarify the contribution of disease, chemotherapy, hormonal therapy, and other risk factors to cognitive outcome in this clinical population.

A clinical prediction rule for pulmonary complications after thoracic surgery for primary lung cancer.

BACKGROUND: There is controversy surrounding the value of the predicted postoperative diffusing capacity of lung for carbon monoxide (DLCOppo) in comparison to the forced expired volume in 1 s for prediction of pulmonary complications (PCs) after thoracic surgery. METHODS: Using a prospective database, we performed an analysis of 956 patients who had resection for lung cancer at a single institution. PC was defined as the occurrence of any of the following: atelectasis, pneumonia, pulmonary embolism, respiratory failure, and need for supplemental oxygen at hospital discharge. RESULTS: PCs occurred in 121 of 956 patients (12.7%). Preoperative chemotherapy (odds ratio 1.64, 95% confidence interval 1.06-2.55, P = 0.02, point score 2) and a lower DLCOppo (odds ratio per each 5% decrement 1.13, 95% confidence interval 1.06-1.19, P < 0.0001, point score 1 per each 5% decrement of DLCOppo less than 100%) were independent risk factors for PCs. We defined 3 overall risk categories for PCs: low < or =10 points, 39 of 448 patients (9%); intermediate 11-13 points, 37 of 256 patients (14%); and high > or =14 points, 42 of 159 patients (26%). The median (range) length of hospital stay was significantly greater for patients who developed PCs than for those who did not: 12 (3-113) days vs 6 (2-39) days, P < 0.0001, respectively. Similarly, 30-day mortality was significantly more frequent for patients who developed PCs than for those who did not: 16 of 121 (13.2%) vs 6 of 835 (0.7%), P < 0.0001. CONCLUSIONS: These data show that PCs after thoracic surgery for lung cancer can be predicted with moderate accuracy based on DLCOppo and whether patients had chemotherapy. Forced expired volume in 1 s was not a predictor of PCs.

Increased preoperative white blood cell count predicts postoperative atrial fibrillation after coronary artery bypass surgery.

OBJECTIVE: To better understand the relationship between humoral and cellular markers of inflammation and postoperative atrial fibrillation (AF). DESIGN: A prospective and descriptive study. SETTING: Academic institution. PARTICIPANTS: Sixty adult patients > or = 60 years of age presenting for elective coronary artery bypass surgery with cardiopulmonary bypass (CPB). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: With institutional review board approval, serial measurements for high sensitivity C-reactive protein (CRP) and white blood cell count (WBC) were performed before the induction of anesthesia, on arrival in the intensive care unit, and on the mornings of postoperative days 1 and 2. Continuous telemetry and daily 12-lead electrocardiographs were used to confirm new-onset AF. AF occurred in 17 of 60 (28%; 95% confidence interval, 17%-41%) patients. A history of preoperative myocardial infarction was more frequent among patients who developed AF (p = 0.049). Patients with or without AF did not differ in CRP values at any of the 4 study time points (p = 0.61 to p = 0.81). Preoperative WBC values were higher for patients who developed AF, and, according to stepwise logistic regression, it was the sole independent predictor of postoperative AF (odds ratio = 6.7; 95% confidence interval, 1.6-29.0; p = 0.01). A 2-fold higher preoperative WBC was associated with a nearly 7-fold higher risk of developing AF, and WBC >7 x 10(9)/L was associated with a nearly 4-fold higher risk of AF (odds ratio = 3.8, p = 0.03). CONCLUSION: In this cohort of patients undergoing CABG surgery, preoperative leukocytosis was a significant predictor of AF independent of CRP.

Imaging of HSV-tk Reporter gene expression: comparison between [18F]FEAU, [18F]FFEAU, and other imaging probes.

UNLABELLED: Herpes virus type 1 thymidine kinase (HSV1-tk) and the mutant HSV1-sr39tk are the 2 most widely used "reporter genes" for radiotracer-based imaging. Two pyrimidine nucleoside analogs, [18F]FEAU (1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)-5-ethyluridine) and [18F]FFEAU (1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)-5-(2-fluoroethyl)uridine), have generated recent interest as potential new probes for imaging HSV1-tk and HSV1-sr39tk gene expression. METHODS: We compared [18F]FEAU and [18F]FFEAU with a series of other pyrimidine nucleoside derivatives (including 1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)-5-iodouridine [FIAU]) and with acycloguanosine analogs using a stable HSV1-tk transduced cell line (RG2TK+) and wild-type RG2 cells. RESULTS: The in vitro accumulation data and the calculated and normalized clearance constant, nKi, as well as sensitivity and selectivity indices indicated that 2 pyrimidine nucleoside probes, [18F]FEAU and [18F]FFEAU, had the best uptake characteristics. These probes were selected for further dynamic PET studies in nude rats bearing subcutaneous RG2TK+ and RG2 tumors. The 2-h postinjection [18F]FEAU uptake levels were 3.3% +/- 1.0% and 0.28% +/- 0.07% dose/cm3 in subcutaneous RG2TK+ and RG2 tumors, respectively, and 2.3% +/- 0.2% and 0.19% +/- 0.01% dose/cm3, respectively, for [18F]FFEAU. The corresponding RG2TK+/RG2 uptake ratios were 11.5 +/- 1.5 and 12.2 +/- 1.4, respectively. The inherent problem of comparing different radiolabeled pyrimidine nucleoside and guanosine-based probes for imaging HSV1-tk expression using different transduced cell lines and assay systems in the absence of an independent thymidine kinase-enzyme assay is discussed. CONCLUSION: For HSV1-tk reporter systems that require a 1- to 4-h PET paradigm, HSV1-tk-[18F]FEAU is the current top contender.

Inhibition of Jun NH2-terminal kinases suppresses the growth of experimental head and neck squamous cell carcinoma.

PURPOSE: This study was carried out to investigate whether c-Jun NH2-terminal kinases (JNK) are potential targets for treating head and neck squamous cell carcinoma (HNSCC). EXPERIMENTAL DESIGN: JNK activity was first evaluated in 20 paired samples of human HNSCC. The antitumor activity of SP600125, a reversible nonselective ATP-competitive inhibitor of JNKs, was then investigated both in an HNSCC xenograft model and in vitro using immunohistochemistry, immunoblotting, enzyme immunoassay, flow cytometry, and a Matrigel assay of capillary tube formation. Complementary studies were carried out using small interfering RNA to JNK1/2. RESULTS: JNK activity was increased in human HNSCC compared with normal-appearing epithelium. Treatment of mice bearing HNSCC xenografts with SP600125 resulted in >60% inhibition of tumor growth relative to vehicle-treated animals. Inhibition of tumor growth was associated with significant reductions in both cell proliferation and microvessel density. SP600125 inhibited tumor cell proliferation by causing delays in both the S and G2-M phases of the cell cycle. Inhibition of angiogenesis seemed to reflect effects on both tumor and endothelial cells. The JNK inhibitor suppressed the production of vascular endothelial growth factor and interleukin-8 by tumor cells and also inhibited endothelial cell proliferation and capillary tube formation. Reduced amounts and phosphorylation of epidermal growth factor receptor were found in tumor cells after treatment with SP600125. Small interfering RNA-mediated suppression of JNK1/2 led to reduced tumor cell proliferation and decreased levels of epidermal growth factor receptor, vascular endothelial growth factor, and interleukin-8. CONCLUSIONS: JNK activity is commonly increased in HNSCC. Our preclinical results provide a rationale for evaluating JNK inhibition as an approach to treating HNSCC.

Practice patterns in choice of left double-lumen tube size for thoracic surgery.

BACKGROUND: Some anesthesiologists choose smaller than body size-appropriate left sided double-lumen tubes (DLTs) ("down-size") for lung isolation in an attempt to limit the risk of airway trauma. There are few data on the effects of DLT size on intraoperative outcome measures. METHODS: In 300 adults undergoing thoracic surgery requiring lung isolation, we conducted a prospective pilot study to evaluate whether the use of 35 FR DLT, regardless of gender and/or height (care standard of two investigators), was associated with a similar incidence of intraoperative hypoxemia, lung isolation failure, or need for DLT repositioning during surgery (noninferiority) than with the conventional goal of inserting the largest possible DLT (care standard of two other investigators). DLT insertion position was immediately confirmed with fiberoptic bronchoscopy after direct laryngoscopic placement and after lateral positioning. RESULTS: The combined incidence of transient hypoxemia, inadequate lung isolation, or need for DLT repositioning during surgery did not differ among patients receiving 35, 37, or 39 FR DLT, regardless of gender or height. Despite the high frequency of 35 FR DLT use, 2% of patients required further down-sizing due to the inability to introduce the DLT into the left mainstem bronchus or when no inflation of the bronchial cuff was needed for lung isolation. CONCLUSIONS: Under the conditions of this pilot study, the use of smaller than conventionally sized DLT was not associated with any differences in clinical intraoperative outcomes.

Inflammation and outcome after general thoracic surgery.

OBJECTIVE: To determine whether preoperative inflammation predisposes to major postoperative complications (PC) and poor outcome. METHODS: Prospective data collection of 153 consecutive patients aged 73+/-6 years scheduled for lung resection at a tertiary cancer center. High sensitivity C-reactive protein (CRP) and interleukin (IL)-6 levels were measured before surgery, on arrival to the postanesthesia care unit, and on the first morning after surgery. RESULTS: PC occurred in 9/153 (5.9%) patients. In comparison to patients without PC, those with PC had a greater history of hypertension (P=0.047), higher frequency of non-steroidal anti-inflammatory drug use (P=0.007) and had a lower preoperative albumin level, 3.75+/-0.65 g/dl versus 4.28+/-0.33 g/dl, P=0.03. Receiver operating characteristic analysis demonstrated a strong association between PC and preoperative CRP (area under the curve of 0.86), albumin (area under the curve of 0.86) and less so for IL-6 (area under the curve of 0.79). CONCLUSIONS: Markers of inflammation, CRP and IL-6, can help distinguish patients who are at high risk for major PC. These preliminary and novel data suggest that in addition to low albumin, a previously described marker of outcome, systemic inflammation is likely to be important in the pathogenesis of important PC.

A quantitative measurement of the human somatic mutation rate.

The mutation rate (mu) is a key biological feature of somatic cells that determines risk for malignant transformation, and it has been exceedingly difficult to measure in human cells. For this purpose, a potential sentinel is the X-linked PIG-A gene, because its inactivation causes lack of glycosylphosphatidylinositol-linked membrane proteins. We previously found that the frequency (f) of PIG-A mutant cells can be measured accurately by flow cytometry, even when f is very low. Here we measure both f and mu by culturing B-lymphoblastoid cell lines and first eliminating preexisting PIG-A mutants by flow sorting. After expansion in culture, the frequency of new mutants is determined by flow cytometry using antibodies specific for glycosylphosphatidylinositol-linked proteins (e.g., CD48, CD55, and CD59). The mutation rate is then calculated by the formula mu = f/d, where d is the number of cell divisions occurring in culture. The mean mu in cells from normal donors was 10.6 x 10(-7) mutations per cell division (range 2.4 to 29.6 x 10(-7)). The mean mu was elevated >30-fold in cells from patients with Fanconi anemia (P < 0.0001), and mu varied widely in ataxia-telangiectasia with a mean 4-fold elevation (P = 0.002). In contrast, mu was not significantly different from normal in cells from patients with Nijmegen breakage syndrome. Differences in mu could not be attributed to variations in plating efficiency. The mutation rate in man can now be measured routinely in B-lymphoblastoid cell lines, and it is elevated in cancer predisposition syndromes. This system should be useful in evaluating cancer risk and in the design of preventive strategies.

HER2/neu-induced mammary tumorigenesis and angiogenesis are reduced in cyclooxygenase-2 knockout mice.

The inducible prostaglandin synthase cyclooxygenase-2 (Cox-2) is overexpressed in approximately 40% of human breast cancers and at higher frequencies in preinvasive ductal carcinoma in situ (DCIS). Cox-2 expression is particularly associated with overexpression of human epidermal growth factor receptor 2 (HER2/neu). To definitively interrogate the role of Cox-2 in mammary neoplasia, we have used a genetic approach, crossing Cox-2-deficient mice with a HER2/neu transgenic strain, MMTV/NDL. At 20 weeks of age, mammary glands from virgin MMTV/NDL females contained multiple focal tumors, or mammary intraepithelial neoplasias, which histologically resembled human DCIS. Mammary tumor multiplicity and prostaglandin E2 (PGE2) levels were significantly decreased in Cox-2 heterozygous and knockout animals relative to Cox-2 wild-type controls. Notably, the proportion of larger tumors was decreased in Cox-2-deficient mice. HER2/neu-induced mammary hyperplasia was also substantially reduced in Cox-2 null mice. Additionally, mammary glands from Cox-2 knockout mice exhibited a striking reduction in vascularization, and expression of proangiogenic genes was correspondingly reduced. Decreased vascularization was observed both in dysplastic and normal-appearing regions of Cox-2-null mammary glands. Our data provide the first genetic evidence that Cox-2 contributes to HER2/neu-induced mammary tumorigenesis. This finding may help to explain the reduced risk of breast cancer associated with regular use of nonsteroidal anti-inflammatory drugs.

Chemotherapy induces the expression of cyclooxygenase-2 in non-small cell lung cancer.

PURPOSE: To determine the effect of taxane-based chemotherapy on intratumoral levels of cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)) in patients with non-small cell lung cancer (NSCLC). EXPERIMENTAL DESIGN: Lung specimens obtained at the time of surgery were used to measure levels of COX-2 and PGE(2) in tumors and adjacent nontumorous tissues in three subsets of NSCLC patients who underwent: (A) surgical resection only (n = 16); (B) surgical resection after preoperative taxane-based chemotherapy (n = 13); or (C) surgical resection after preoperative chemotherapy coadministered with the selective COX-2 inhibitor, celecoxib 400 mg bid (n = 17). RESULTS: Levels of intratumoral PGE(2) were nearly 3-fold higher among patients who received preoperative chemotherapy compared with those treated by surgery alone (P < 0.001). This difference was abrogated by the addition of celecoxib to preoperative chemotherapy (P < 0.001). Amounts of intratumoral COX-2 were approximately 3-fold higher in groups of patients who received preoperative chemotherapy with celecoxib (P < 0.0001) or without celecoxib (P < 0.001), compared with the group who underwent surgical resection only. Importantly, statistically significant positive correlations between COX-2 and PGE(2) were observed in the surgery only (r = 0.502, P = 0.047) and preoperative chemotherapy groups (r = 0.740, P = 0.004); this correlation was abrogated when celecoxib was given with chemotherapy (r = 0.005, P = 0.98). CONCLUSIONS: Treatment with chemotherapy led to increased amounts of COX-2 and PGE(2) in NSCLC. Cotreatment with celecoxib abrogated the increase in levels of PGE(2) but not COX-2 induced by chemotherapy. Importantly, these results clearly show that levels of a pharmacologic target (i.e., COX-2) can be affected by both the intrinsic molecular properties of a tumor and therapy.

Celecoxib inhibits prostate cancer growth: evidence of a cyclooxygenase-2-independent mechanism.

PURPOSE: Selective cyclooxygenase-2 (COX-2) inhibitors may suppress carcinogenesis by both COX-2-dependent and COX-2-independent mechanisms. The primary purpose of this study was to evaluate whether celecoxib or rofecoxib, two widely used selective COX-2 inhibitors, possess COX-2-independent antitumor activity. EXPERIMENTAL DESIGN: PC3 and LNCaP human prostate cancer cell lines were used to investigate the growth inhibitory effects of selective COX-2 inhibitors in vitro. To complement these studies, we evaluated the effect of celecoxib on the growth of PC3 xenografts. RESULTS: COX-1 but not COX-2 was detected in PC3 and LNCaP cells. Clinically achievable concentrations (2.5-5.0 micromol/L) of celecoxib inhibited the growth of both cell lines in vitro, whereas rofecoxib had no effect over the same concentration range. Celecoxib inhibited cell growth by inducing a G(1) cell cycle block and reducing DNA synthesis. Treatment with celecoxib also led to dose-dependent inhibition of PC3 xenograft growth without causing a reduction in intratumor prostaglandin E(2). Inhibition of tumor growth occurred at concentrations (2.37-5.70 micromol/L) of celecoxib in plasma that were comparable with the concentrations required to inhibit cell growth in vitro. The highest dose of celecoxib led to a 52% reduction in tumor volume and an approximately 50% decrease in both cell proliferation and microvessel density. Treatment with celecoxib caused a marked decrease in amounts of cyclin D1 both in vitro and in vivo. CONCLUSIONS: Two clinically available selective COX-2 inhibitors possess different COX-2-independent anticancer properties. The anticancer activity of celecoxib may reflect COX-2-independent in addition to COX-2-dependent effects.

Identification of prognostic markers in bone sarcomas using proton-decoupled phosphorus magnetic resonance spectroscopy.

It has been hypothesized that the (31)Phosphorus ((31)P) nuclear magnetic resonance spectrum from certain tumors may provide prognostic information. The goal of the present study was to identify prognostic metabolic markers by using proton-decoupled phosphorus magnetic resonance spectroscopic imaging ((31)P MRSI). Twenty patients with bone [osteogenic (OS) and Ewing's (ES) and/or primitive neuroectodermal tumor (PNET)] sarcoma, treated with chemotherapy and surgery or with chemotherapy alone, underwent (31)P MRSI studies pre- and post-therapy. The studies were performed on a 1.5 Tesla General Electric (GE) clinical scanner equipped with a stand-alone proton decoupler and a dual (1)H/(31)P surface coil pair. The limited sensitivity of the (31)P nucleus required that a large soft tissue component of the disease be located within 10 cm (maximum distance) of the body surface and the use of a highly sensitive coil placed near the skin surface. Proton decoupling and nuclear Overhauser enhancement were used to improve the spectral resolution and signal:noise ratio. Baseline (31)P spectral features and metabolic changes with treatment were compared with treatment outcome. The patients were categorized depending on survival as event-free survivors or those who died. The pretreatment nucleoside triphosphate:inorganic phosphate (NTP:P(i)) ratio, an index of tumor bioenergetic status, was significant (P = 0.003) in differentiating event-free survivors versus those who died. The pretreatment NTP:P(i) was higher in patients who were destined to undergo a durable event-free survival compared with those who died. The results are promising, although a prospective study is necessary for confirmation. (31)P MRSI appears to be a useful tool for the prediction of survival before therapy in bone sarcomas.