Validation of metastasis-free survival as a surrogate endpoint for overall survival in localized prostate cancer in the era of docetaxel for castration-resistant prostate cancer.

BACKGROUND: Prior work from the Intermediate Clinical Endpoints in Cancer of the Prostate (ICECaP) consortium (ICECaP-1) demonstrated that metastasis-free survival (MFS) is a valid surrogate for overall survival (OS) in localized prostate cancer (PCa). This was based on data from patients treated predominantly before 2004, prior to docetaxel being available for the treatment of metastatic castrate-resistant prostate cancer (mCRPC). We sought to validate surrogacy in a more contemporary era (ICECaP-2) with greater availability of docetaxel and other systemic therapies for mCRPC. PATIENTS AND METHODS: Eligible trials for ICECaP-2 were those providing individual patient data (IPD) after publication of ICECaP-1 and evaluating adjuvant/salvage therapy for localized PCa, and which collected MFS and OS data. MFS was defined as distant metastases or death from any cause, and OS was defined as death from any cause. Surrogacy was evaluated using a meta-analytic two-stage validation model, with an R2 ≥ 0.7 defined a priori as clinically relevant. RESULTS: A total of 15 164 IPD from 14 trials were included in ICECaP-2, with 70% of patients treated after 2004. The median follow-up was 8.3 years and the median postmetastasis survival was 3.1 years in ICECaP-2, compared with 1.9 years in ICECaP-1. For surrogacy condition 1, Kendall's tau was 0.92 for MFS with OS at the patient level, and R2 from weighted linear regression (WLR) of 8-year OS on 5-year MFS was 0.73 (95% confidence interval 0.53-0.82) at the trial level. For condition 2, R2 was 0.83 (95% confidence interval 0.64-0.89) from WLR of log[hazard ratio (HR)]-OS on log(HR)-MFS. The surrogate threshold effect on OS was an HR(MFS) of 0.81. CONCLUSIONS: MFS remained a valid surrogate for OS in a more contemporary era, where patients had greater access to docetaxel and other systemic therapies for mCRPC. This supports the use of MFS as the primary outcome measure for ongoing adjuvant trials in localized PCa.

Disease volumes as a marker for patient response in malignant pleural mesothelioma.

BACKGROUND: The goal of this study was to create a comprehensive model for malignant pleural mesothelioma patient survival utilizing continuous, time-varying estimates of disease volume from computed tomography (CT) imaging in conjunction with clinical covariates. PATIENTS AND METHODS: Serial CT scans were obtained during the course of clinically standard chemotherapy for 81 patients. The pleural disease volume was segmented for each of the 281 CT scans, and relative changes in disease volume from the baseline scan were tracked over the course of serial follow-up imaging. A prognostic model was built using time-varying disease volume measurements in conjunction with clinical covariates. RESULTS: Over the course of treatment, disease volume decreased by an average of 19%, and median patient survival was 12.6 months from baseline. In a multivariate survival model, changes in disease volume were significantly associated with patient survival along with disease histology, Eastern Cooperative Oncology Group performance status, and presence of dyspnea. CONCLUSIONS: Analysis of the trajectories of disease volumes during chemotherapy for patients with mesothelioma indicates that increasing disease volume was significantly and independently associated with poor patient prognosis in both univariate and multivariate survival models.

Models for the binary complex of bacteriophage T4 gp59 helicase loading protein: gp32 single-stranded DNA-BINDING protein and ternary complex with pseudo-Y junction DNA.

Bacteriophage T4 gp59 helicase assembly protein (gp59) is required for loading of gp41 replicative helicase onto DNA protected by gp32 single-stranded DNA-binding protein. The gp59 protein recognizes branched DNA structures found at replication and recombination sites. Binding of gp32 protein (full-length and deletion constructs) to gp59 protein measured by isothermal titration calorimetry demonstrates that the gp32 protein C-terminal A-domain is essential for protein-protein interaction in the absence of DNA. Sedimentation velocity experiments with gp59 protein and gp32ΔB protein (an N-terminal B-domain deletion) show that these proteins are monomers but form a 1:1 complex with a dissociation constant comparable with that determined by isothermal titration calorimetry. Small angle x-ray scattering (SAXS) studies indicate that the gp59 protein is a prolate monomer, consistent with the crystal structure and hydrodynamic properties determined from sedimentation velocity experiments. SAXS experiments also demonstrate that gp32ΔB protein is a prolate monomer with an elongated A-domain protruding from the core. Fitting structures of gp59 protein and the gp32 core into the SAXS-derived molecular envelope supports a model for the gp59 protein-gp32ΔB protein complex. Our earlier work demonstrated that gp59 protein attracts full-length gp32 protein to pseudo-Y junctions. A model of the gp59 protein-DNA complex, modified to accommodate new SAXS data for the binary complex together with mutational analysis of gp59 protein, is presented in the accompanying article (Dolezal, D., Jones, C. E., Lai, X., Brister, J. R., Mueser, T. C., Nossal, N. G., and Hinton, D. M. (2012) J. Biol. Chem. 287, 18596-18607).

Patterns of missing mini mental status exam (MMSE) in radiation therapy oncology group (RTOG) brain cancer trials.

The Mini Mental Status Exam (MMSE) instrument has been commonly used in the Radiation Therapy Oncology Group (RTOG) to assess mental status in brain cancer patients. Evaluating patient factors in relation to patterns of incomplete MMSE assessments can provide insight into predictors of missingness and optimal MMSE collection schedules in brain cancer clinical trials. This study examined eight RTOG brain cancer trials with ten treatment arms and 1,957 eligible patients. Patient data compliance patterns were categorized as: (1) evaluated at all time points (Complete), (2) not evaluated from a given time point or any subsequent time points but evaluated at all the previous time points (Monotone drop-out), (3) not evaluated at any time point (All missing), and (4) all other patterns (Mixed). Patient characteristics and reasons for missingness were summarized and compared among the missing pattern groups. Baseline MMSE scores and change scores after radiation therapy (RT) were compared between these groups, adjusting for differences in other characteristics. There were significant differences in frequency of missing patterns by age, treatment type, education, and Zubrod performance status (ZPS; P < 0.001). Ninety-two percent of patients were evaluated at least once: seven percent of patients were complete pattern, 49% were Monotone pattern, and 36% were mixed pattern. Patients who received RT only regimens were evaluated at a higher rate than patients who received RT + other treatments (49-64% vs. 27-45%). Institutional error and request to not be contacted were the most frequent known reasons for missing data, but most often, reasons for missing MMSE was unspecified. Differences in baseline mean MMSE scores by missing pattern (Complete, Monotone dropout, Mixed) were statistically significant (P < 0.001) but differences were small (<1.5 points) and significance did not persist after adjustment for age, ZPS, and other factors related to missingness. Post-RT change scores did not differ significantly by missing pattern. While baseline and change scores did not differ widely by missing pattern for available measurements, incomplete data was common and of unknown reason, and has potential to substantially bias conclusions. Higher compliance rates may be achievable by addressing institutional compliance with assessment schedules and patient refusal issues, and further exploration of how educational and health status barriers influence compliance with MMSE and other tools used in modern neurocognitive batteries.

Use of multiple fluorophores for evaluating microvascular permeability in control rats and rats with sepsis.

Capillary leak accompanying systemic inflammatory response conditions is a significant clinical problem. In the present study, we describe and verify a method for studying capillary leak that is based on the injection of proteins that differ significantly in size and have spectrally distinguishable fluorophores. Control (n=11) and post-CLP (caecal ligation and puncture; n=14) Sprague-Dawley rats were injected with tracer amounts of albumin and PEG-Alb [albumin covalently linked to methoxy-poly(ethylene glycol)] labelled with fluorescein and Texas Red. Blood samples were withdrawn between 5 min and 144 h, and the fluorescence of the labelled proteins was determined. The relative retention of the PEG-Alb and albumin was assessed via measurement of the TER (transcapillary escape rate; in %/h) and the t(50%) estimate, defined as the time when the actual concentration reached 50% of its baseline. The concentration-time trends for both albumin and PEG-Alb tracers exhibited two-compartmental behaviour and were analysed using bi-exponential modelling. Retention times were significantly greater for PEG-Alb in both control and CLP rats. TER(PEG-Alb) was significantly lower than TER(albumin) for both control (8.1+/-5.6 compared with 14.8+/-7.1 %/h respectively; P<0.01) and CLP (14.8+/-6.6 compared with 22.5+/-7.3 %/h respectively; P<0.001) rats. The t(50%[PEG-Alb]) was substantially greater than the corresponding t(50%[albumin]) for both control (29.8+/-9.8 compared with 7.2+/-2.0 h respectively; P<0.001) and CLP (12.9+/-5.6 compared with 5.1+/-1.6 h respectively; P<0.001) rats. The result was similar irrespective of the fluorophore-protein combination, validating the multifluorophore technique. In conclusion, the double-fluorophore approach described in the present study may provide the future basis for a method to quantify capillary leak in disease.

Noncanonical function of glutamyl-prolyl-tRNA synthetase: gene-specific silencing of translation.

Aminoacyl tRNA synthetases (ARS) catalyze the ligation of amino acids to cognate tRNAs. Chordate ARSs have evolved distinctive features absent from ancestral forms, including compartmentalization in a multisynthetase complex (MSC), noncatalytic peptide appendages, and ancillary functions unrelated to aminoacylation. Here, we show that glutamyl-prolyl-tRNA synthetase (GluProRS), a bifunctional ARS of the MSC, has a regulated, noncanonical activity that blocks synthesis of a specific protein. GluProRS was identified as a component of the interferon (IFN)-gamma-activated inhibitor of translation (GAIT) complex by RNA affinity chromatography using the ceruloplasmin (Cp) GAIT element as ligand. In response to IFN-gamma, GluProRS is phosphorylated and released from the MSC, binds the Cp 3'-untranslated region in an mRNP containing three additional proteins, and silences Cp mRNA translation. Thus, GluProRS has divergent functions in protein synthesis: in the MSC, its aminoacylation activity supports global translation, but translocation of GluProRS to an inflammation-responsive mRNP causes gene-specific translational silencing.

Plasma expansion by polyethylene-glycol-modified albumin.

Systemic inflammatory response conditions are associated with capillary leak and haemodynamic compromise. Fluid resuscitation to reverse the ensuing hypovolaemia is, however, complicated by the decreased endothelium reflection coefficient to albumin and other colloids. We developed PEG-Alb (albumin covalently linked to polyethylene glycol) as a potential resuscitative agent. PEG was covalently linked to human albumin at multiple sites on the protein. The modified protein was heterogeneous when examined by SDS/PAGE, size-exclusion chromatography and SELDI-TOF MS (surface-enhanced laser-desorption ionization-time of flight MS). Based on size-exclusion chromatography and osmotic pressure data, the effective volume of PEG-Alb is increased 13- to 16-fold compared with unmodified albumin. In an LPS (lipopolysaccharide) model of shock, rats treated with PEG-Alb showed better blood pressure, lower Hct (haematocrit) consistent with haemodilution and less lung injury than rats treated with unmodified albumin or saline. In a CLP (caecal ligation and puncture) model of sepsis, PEG-Alb was more effective than albumin or saline in maintaining blood pressure and in decreasing Hct. When fluorescein-labelled PEG-Alb and Texas Red-labelled albumin were administered to rats with LPS- or CLP-induced shock, PEG-Alb was retained within blood vessels, whereas albumin extravasates into the interstitial space. Based on these data, PEG-Alb appears to be retained within blood vessels in models of capillary leak. PEG-Alb may ultimately be effective in the clinical treatment of shock associated with capillary leak.

Prevention of invasive breast cancer in women with ductal carcinoma in situ: an update of the National Surgical Adjuvant Breast and Bowel Project experience.

The National Surgical Adjuvant Breast and Bowel Project (NSABP) conducted two sequential randomized clinical trials to aid in resolving uncertainty about the treatment of women with small, localized, mammographically detected ductal carcinoma in situ (DCIS). After removal of the tumor and normal breast tissue so that specimen margins were histologically tumor-free (lumpectomy), 818 patients in the B-17 trial were randomly assigned to receive either radiation therapy to the ipsilateral breast or no radiation therapy. B-24, the second study, which involved 1,804 women, tested the hypothesis that, in DCIS patients with or without positive tumor specimen margins, lumpectomy, radiation, and tamoxifen (TAM) would be more effective than lumpectomy, radiation, and placebo in preventing invasive and noninvasive ipsilateral breast tumor recurrences (IBTRs), contralateral breast tumors (CBTs), and tumors at metastatic sites. The findings in this report continue to demonstrate through 12 years of follow-up that radiation after lumpectomy reduces the incidence rate of all IBTRs by 58%. They also demonstrate that the administration of TAM after lumpectomy and radiation therapy results in a significant decrease in the rate of all breast cancer events, particularly in invasive cancer. The findings from the B-17 and B-24 studies are related to those from the NSABP prevention (P-1) trial, which demonstrated a 50% reduction in the risk of invasive cancer in women with a history of atypical ductal hyperplasia (ADH) or lobular carcinoma in situ (LCIS) and a reduction in the incidence of both DCIS and LCIS in women without a history of those tumors. The B-17 findings demonstrated that patients treated with lumpectomy alone were at greater risk for invasive cancer than were women in P-1 who had a history of ADH or LCIS and who received no radiation therapy or TAM. Although women who received radiation benefited from that therapy, they remained at higher risk for invasive cancer than women in P-1 who had a history of LCIS and who received placebo or TAM. Thus, if it is accepted from the P-1 findings that women at increased risk for invasive cancer are candidates for an intervention such as TAM, then it would seem that women with a history of DCIS should also be considered for such therapy in addition to radiation therapy. That statement does not imply that, as a result of the findings presented here, all DCIS patients should receive radiation and TAM. It does suggest, however, that, in the treatment of DCIS, the appropriate use of current and better therapeutic agents that become available could diminish the significance of breast cancer as a public health problem.

Five versus more than five years of tamoxifen for lymph node-negative breast cancer: updated findings from the National Surgical Adjuvant Breast and Bowel Project B-14 randomized trial.

BACKGROUND: Previously reported information from B-14, a National Surgical Adjuvant Breast and Bowel Project (NSABP) randomized, placebo-controlled clinical trial, demonstrated that patients with estrogen receptor (ER)-positive breast cancer and negative axillary lymph nodes experienced a prolonged benefit from 5 years of tamoxifen therapy. When these women were rerandomized to receive either placebo or more prolonged tamoxifen therapy, they obtained no additional advantage from tamoxifen through 4 years of follow-up. Because the optimal duration of tamoxifen administration continues to be controversial and because there have been 3 more years of follow-up and a substantial increase in the number of events since our last report, an update of the B-14 study is appropriate. METHODS: Patients (n = 1172) who had completed 5 years of tamoxifen therapy and who were disease free were rerandomized to receive placebo (n = 579) or tamoxifen (n = 593). Survival, disease-free survival (DFS), and relapse-free survival (RFS) were estimated by the Kaplan-Meier method; the differences between the treatment groups were assessed by the log-rank test. Relative risks of failure (with 95% confidence intervals) were determined by the Cox proportional hazards model. P values were two-sided. RESULTS: Through 7 years after reassignment of tamoxifen-treated patients to either placebo or continued tamoxifen therapy, a slight advantage was observed in patients who discontinued tamoxifen relative to those who continued to receive it: DFS = 82% versus 78% (P =.03), RFS = 94% versus 92% (P =.13), and survival = 94% versus 91% (P =.07), respectively. The lack of benefit from additional tamoxifen therapy was independent of age or other characteristics. CONCLUSION: Through 7 years of follow-up after rerandomization, there continues to be no additional benefit from tamoxifen administered beyond 5 years in women with ER-positive breast cancer and negative axillary lymph nodes.

Prognosis and treatment of patients with breast tumors of one centimeter or less and negative axillary lymph nodes.

BACKGROUND: Uncertainty about prognosis and treatment of axillary lymph node-negative patients with estrogen receptor (ER)-negative or ER-positive invasive breast tumors of 1 cm or less prompted the analysis of data from five National Surgical Adjuvant Breast and Bowel Project randomized clinical trials. METHODS: Two hundred thirty-five patients with ER-negative tumors and 1024 patients with ER-positive tumors were identified in these trials. Patients with ER-negative tumors received surgery alone or surgery and chemotherapy. Patients with ER-positive tumors received surgery alone; surgery and tamoxifen; or surgery, tamoxifen, and chemotherapy. End points were relapse-free survival (RFS), event-free survival, and overall survival. A result was considered to be statistically significant with a P value of.05 or less; all statistical tests were two-sided. RESULTS: The 8-year RFS of women with ER-negative tumors who received surgery alone or with chemotherapy was 81% and 90%, respectively (P = .06). Survival was similar in both groups (93% and 91%; P = .65). The 8-year RFS of women with ER-positive tumors was 86% after surgery alone, 93% when tamoxifen was added (P = .01), and 95% after the addition of tamoxifen and chemotherapy (P = .07 compared with tamoxifen). Survival in the three groups was 90%, 92% (P = .41), and 97%, respectively. The difference between the latter two groups was significant (P = .01). Regardless of ER status or treatment, overall mortality was 8%; one half of the deaths were related to breast cancer. Several covariates affected the risk of recurrence in ER-negative and ER-positive patients. Risk was greater in women with tumors of 1 cm than in those with tumors of less than 1 cm, in women aged 49 years or younger than in those aged 50 years or older, and in women with infiltrating ductal or lobular carcinoma than in those with other histologic tumor types. CONCLUSIONS: Chemotherapy and/or tamoxifen should be considered for the treatment of women with ER-negative or ER-positive tumors of 1 cm or less and negative axillary lymph nodes.

Equilibrium unfolding of Bombyx mori glycyl-tRNA synthetase.

Unfolding of Bombyx mori glycyl-tRNA synthetase was examined by multiple spectroscopic techniques. Tryptophan fluorescence of wild type enzyme and an N-terminally truncated form (N55) increased at low concentrations of urea or guanidine-HCl followed by a reduction in intensity at intermediate denaturant concentrations; a transition at higher denaturant was detected as decreased fluorescence intensity and a red-shifted emission. Solute quenching of fluorescence indicated that tryptophans become progressively solvent-exposed during unfolding. Wild type enzyme had stronger negative CD bands between 220 and 230 nm than the mutant, indicative of greater alpha-helical content. Urea or guanidine-HCl caused a reduction in ellipticity at 222 nm at low denaturant concentration with the wild type enzyme, a transition that is absent in the mutant; both enzymes exhibited a cooperative transition at higher denaturant concentrations. Both enzymes dissociate to monomers in 1.5 m urea. Unfolding of wild type enzyme is described by a multistate unfolding and a parallel two state unfolding; the two-state component is absent in the mutant. Changes in spectral properties associated with unfolding were largely reversible after dilution to low denaturant. Unfolding of glycyl-tRNA synthetase is complex with a native state, a native-like monomer, partially unfolded states, and the unfolded state.

Efficacy of systemic adjuvant therapy for breast cancer in African-American and Caucasian women.

Observed variations in breast cancer survival by racial/ethnic background have been attributed to many factors, including differences in clinical and pathologic disease features at diagnosis and economic resource inequities that may affect treatment access and quality. In this report, we examine outcomes for African-American and Caucasian breast cancer patients participating in selected randomized clinical trials of the National Surgical Adjuvant Breast and Bowel Project (NSABP) to determine whether prognosis or efficacy of systemic adjuvant therapy differed between these groups. Randomized clinical trials offer the advantages of a similar disease stage and a uniform treatment plan for all participants. Patients from four NSABP trials enrolling patients from 1982 through 1994 with axillary lymph node-negative disease (543 African-American and 7582 Caucasian) and three trials enrolling patients from 1984 through 1991 with axillary lymph node-positive disease (548 African-American and 4986 Caucasian) were included. Disease-free survival (DFS), which was defined as time on study free of breast cancer recurrence, second primary cancer, or death preceding these events, and survival risk ratios (RRs) with two-sided 95% confidence intervals (CIs) for African-Americans versus Caucasians were computed from Cox proportional hazards models that included relevant prognostic covariates. Treatment benefits for the therapies evaluated in these trials were estimated separately for African-Americans and for Caucasians. Among patients with lymph node-negative disease, African-Americans had similar DFS rates to Caucasians (African-American/Caucasian RR = 1.06, 95% CI = 0.92 to 1.23) but had modestly greater mortality rates (RR = 1.21, 95% CI = 1.01 to 1.46). Among lymph node-positive patients, DFS was similar (RR = 1.04, 95% CI = 0.93 to 1.17) and survival was again less favorable for African-Americans (RR = 1.18 95% CI = 1.03 to 1.34). Survival excluding deaths most likely attributable to causes other than cancer was similar between African-Americans and Caucasians (RR = 1.08 [95% CI = 0.88 to 1.33] for lymph node-negative patients and RR = 1.09 [95% CI = 0.96 to 1.25] for lymph node-positive patients). Among lymph node-negative and lymph node-positive patients, African-Americans and Caucasians realized comparable benefit from either the addition of chemotherapy or tamoxifen to surgery alone or the addition of chemotherapy to tamoxifen. In summary, African-American women and Caucasian women who were diagnosed at a comparable disease stage and were similarly treated tended to experience similar breast cancer prognosis. However, a mortality deficit persisted for African-American women relative to Caucasian women, which may be in part due to greater mortality from noncancer causes among African-Americans. Benefit from systemic adjuvant therapy for recurrence and mortality reduction was comparable between African-Americans and Caucasians. This study and investigations in other health-care settings suggest that African-American women and Caucasian women with breast cancer derive a similar benefit from systemic adjuvant therapy when it is administered in accordance with their clinical and pathologic disease presentation.

Duration of adjuvant tamoxifen therapy.

The benefit of using adjuvant tamoxifen to treat breast cancer has been firmly established for patients with estrogen receptor (ER)-positive tumors, regardless of age, lymph node status, or menopausal status. Uncertainty remains, however, regarding the optimal duration of tamoxifen therapy. We reviewed the findings of randomized clinical trials that directly compared alternative treatment durations. Trials comparing short-term adjuvant treatment with tamoxifen (i.e., 1-3 years) with treatments having durations of about 5 years consistently have demonstrated additional benefits stemming from the longer therapy. Trials testing 5 years of treatment with longer durations have, in the aggregate, suggested no additional benefit for the patient. Nevertheless, the number of recurrences reported to date in these trials is not large, and the results of the individual trials are heterogeneous. Furthermore, as a result of tamoxifen's "carryover" effect, duration trials require considerable follow-up before definitive results can be established. Until more definitive data become available, adjuvant treatment with tamoxifen should be limited to 5 years outside the clinical trials setting. Continued accrual of ER-positive patients to ongoing tamoxifen duration trials, including the Adjuvant Tamoxifen Treatment Offer More (aTTom) and Adjuvant Tamoxifen Longer Against Shorter (ATLAS) trials, is appropriate. Alternatively, patients who remain disease free after 5 years of tamoxifen therapy should be encouraged to participate in trials testing crossover to other hormonal interventions, including selective ER modulators or aromatase inhibitors.

Findings from recent National Surgical Adjuvant Breast and Bowel Project adjuvant studies in stage I breast cancer.

Before 1989, credible information about the treatment of breast cancer was derived mainly from randomized clinical trials that enrolled women with either metastatic (stage IV); locally advanced (stage III); or primary, operable, axillary lymph node-positive (stage II) disease. This report provides information from six recent National Surgical Adjuvant Breast and Bowel Project (NSABP) trials involving lymph node-negative (stage I) patients. Findings from NSABP B-13 demonstrated, through 14 years of follow-up, improvements in disease-free survival (DFS) and overall survival from methotrexate and fluorouracil (MF), regardless of age, in women with estrogen receptor (ER)-negative tumors. Results from NSABP B-19, which was conducted with similar patients, demonstrated, through 8 years, a greater overall DFS and survival advantage with cyclophosphamide and MF (CMF) than that observed with MF. Findings from NSABP B-23, in which patients similar to those in B-13 and B-19 were randomly assigned to receive CMF plus placebo, CMF plus tamoxifen (TAM), doxorubicin (Adriamycin) and cyclophosphamide (AC) plus placebo, or AC plus TAM, demonstrated no difference in relapse-free survival (RFS) or overall survival among the four groups through 5 years, either for all patients or relative to age. NSABP B-14, which was carried out in women with ER-positive tumors, compared the outcomes of those who received either placebo or TAM. Through 14 years, superior DFS and overall survival advantages, as well as a reduction in contralateral breast cancer, were observed with TAM. No additional benefit resulted from TAM administration beyond 5 years. Findings from NSABP B-20, a second study conducted in patients with ER-positive tumors, showed, after 8 years, both a DFS and an overall survival advantage from TAM plus either MF or CMF over that achieved with TAM alone. A recent meta-analysis in women with negative lymph nodes and either ER-negative or ER-positive tumors of less than or equal to 1 cm in size was conducted using patients from five NSABP trials. After 8 years, the RFS in women with ER-negative tumors was greater in the group treated with surgery and chemotherapy than in those who underwent surgery alone. In women with ER-positive tumors, RFS and overall survival advantages were observed from the addition of chemotherapy to TAM when that treatment regimen was compared with TAM alone. In addition, evidence has been presented from NSABP B-21, a trial evaluating radiation therapy (XRT) and/or TAM for the prevention of ipsilateral breast tumor recurrence (IBTR) after lumpectomy in women with tumors less than or equal to 1 cm. Findings have shown that XRT is superior to TAM and that XRT + TAM is superior to XRT alone for preventing IBTR. The findings demonstrate that chemotherapy and/or hormonal therapy is effective for the management of women with negative axillary lymph nodes and either ER-negative or ER-positive tumors. Because it also has been proven effective in women with tumors less than or equal to 1 cm, such therapy might also be considered in the treatment of that patient population.

Differences in breast cancer prognosis among African-American and Caucasian women.

This review explores factors potentially contributing to the disparity in survival after breast cancer between African-American and Caucasian women in the United States. A number of factors have been implicated as the cause of poorer survival for black women, including clinical and pathologic features of the disease that are indicative of poor prognosis, economic resource inequities, and differences in treatment access and efficacy. The latter is explored in detail using data from the National Surgical Adjuvant Breast and Bowel Project (NSABP), a nationwide multicenter clinical trials group for breast and colorectal cancers. Key studies into the disparity in breast cancer survival are reviewed according to proposed principal determinants of poorer outcome for black women. Results among black and white women participating in several randomized NSABP clinical trials are also presented. Primary endpoints in those studies were clinical and pathologic disease characteristics at study entry, time to disease progression or new cancers, and total survival time after breast cancer diagnosis and treatment. In most studies reported in the literature, the primary explanatory factor alone, such as stage of disease at diagnosis, did not fully account for differences in outcome between groups; when additional factors were taken into account, however, prognoses became more similar. Results from the NSABP clinical trials similarly indicated that when stage of disease and treatment were comparable, outcomes for blacks did not differ markedly from those of whites. In summary, black women, diagnosed at comparable disease stage as white women and treated appropriately, tend to experience similar breast cancer prognoses and survival. However, important clinical and pathologic disease characteristics may continue to place certain women at increased risk of poorer outcome, and warrant continued study. The opportunity for increased clinical trial participation by black women is encouraged.

Intracellular mRNA cleavage induced through activation of RNase P by nuclease-resistant external guide sequences.

Most antisense oligonucleotide experiments are performed with molecules containing RNase H-competent backbones. However, RNase H may cleave nontargeted mRNAs bound to only partially complementary oligonucleotides. Decreasing such "irrelevant cleavage" would be of critical importance to the ability of the antisense biotechnology to provide accurate assessment of gene function. RNase P is a ubiquitous endogenous cellular ribozyme whose function is to cleave the 5' terminus of precursor tRNAs to generate the mature tRNA. To recruit RNase P, complementary oligonucleotides called external guide sequences (EGS), which mimic structural features of precursor tRNA, were incorporated into an antisense 2'-O-methyl oligoribonucleotide targeted to the 3' region of the PKC-alpha mRNA. In T24 human bladder carcinoma cells, these EGSs, but not control sequences, were highly effective in downregulating PKC-alpha protein and mRNA expression. Furthermore, the downregulation is dependent on the presence of, and base sequence in, the T-loop. Similar observations were made with an EGS targeted to the bcl-xL mRNA.

Outcomes among African-Americans and Caucasians in colon cancer adjuvant therapy trials: findings from the National Surgical Adjuvant Breast and Bowel Project.

BACKGROUND: African-Americans generally have lower survival rates from colon cancer than Caucasian Americans. This disparity has been attributed to many sources, including diagnosis at later disease stage and other unfavorable disease features, inadequate treatment, and socioeconomic factors. The randomized clinical trial setting ensures similarity in disease stage and a uniform treatment plan between blacks and whites. In this study, we evaluated survival and related end points for African-American and Caucasian patients with colon cancer participating in randomized clinical trials of the National Surgical Adjuvant Breast and Bowel Project (NSABP) to determine whether outcomes were less favorable for African-Americans. METHODS: The study included African-American (n = 663) or Caucasian (n = 5969) patients from five serially conducted, randomized clinical trials of the NSABP. We compared recurrence-free survival, disease-free survival (recurrence, new primary cancer, or death), and survival (death from any cause) between blacks and whites by using statistical modeling to account for differences in patient and disease characteristics between the groups. Statistical tests were two-sided. RESULTS: Dukes' stage and number of positive lymph nodes were remarkably similar between African-American and Caucasian patients in each trial. Over all trials combined, an 8% (95% confidence interval [CI] = -6% to 25%; P =.27) excess risk of colon cancer recurrence that was not statistically significant was observed for blacks. A greater disparity in survival was seen, with blacks experiencing a statistically significant 21% (95% CI = 6%-37%; P =.004) greater risk of death. Treatment efficacy appeared similar between the groups. CONCLUSIONS: While the overall survival prognosis was less favorable for African-Americans compared with Caucasians in these trials, other outcomes measured were considerably more similar than those seen in the population at large, suggesting that earlier detection and adjuvant therapy could appreciably improve colon cancer prognosis for African-Americans. Continued investigations into causes of the deficits noted are warranted.

Pathologic findings from the National Surgical Adjuvant Breast Project (NSABP) eight-year update of Protocol B-17: intraductal carcinoma.

BACKGROUND: This report is an 8-year update of the authors' previous findings from National Surgical Adjuvant Breast Project (NSABP) Protocol B-17, which relates to the influence of pathologic characteristics on the natural history and treatment of intraductal carcinoma (DCIS). METHODS: Nine pathologic features observed in a pathologic subset of 623 of 814 evaluable women enrolled in this randomized clinical trial were assessed for their role in the prediction of second ipsilateral breast tumors (IBT), other events, and selection of breast irradiation (XRT) following lumpectomy. RESULTS: The frequency of subsequent IBT was reduced from 31% to 13% (P = 0.0001) by XRT. The average annual hazard rates for IBT were reduced by XRT for all pathologic features examined. Four characteristics were individually noted to be significantly related to IBT, but only moderate-to-marked and absent-to-slight comedo necrosis were found to be independent high and low risk predictors, respectively, for such an event in patients of both treatment groups. XRT effected a 7% absolute reduction at 8 years in the low risk group. Despite a relatively high incidence (approximately 40%) of IBT consisting of invasive cancer, mortality due to breast carcinoma after DCIS for the entire cohort was found to be only 1.6% at 8 years. CONCLUSIONS: The degree of comedo necrosis in patients with DCIS appears to be sufficient for discriminating between high and low risks for IBT following lumpectomy for DCIS. Although margin status, unlike in our previous report, was found to have only a slight or borderline influence on the frequency of IBT at 8 years, excision of DCIS with free margins is advised. The low risk group exhibits a statistically significant reduction of IBT from XRT. The decision to forgo XRT in the treatment of this singular subset of patients would appear to depend on clinical considerations and the input of informed patients rather than being standard practice. [See editorial on pages 375-7, this issue.]