Ribosomal frameshifting, jumping and readthrough.

New examples of high-level ribosomal frameshift and readthrough events have been described over the past year and a half. These include -1 frameshifting at tandem codons and +1 frameshifting at neighboring slow codons. Several bizarre examples of ribosome jumping and multiple stop-codon readthrough continue to perplex investigators in this field.

Defining a transcriptional fingerprint of murine splenic B-cell development.

B-cell development occurs in a stepwise fashion that can be followed by the expression of B cell-specific surface markers. In this study, we wished to identify proteins that could contribute to the changes in expression of such markers. By using RNA from freshly isolated B220+ cells, we hoped to reduce the effect of artifacts that occur during the isolation and amplification steps necessary to use flow cytometry analysis-sorted subsets in microarray experiments. Analyses comparing expression patterns from B220+ 2-week bone marrow (pro-B, pre-B, immature B cells), 2-week spleen (predominantly transitional cells) and 8-week spleen (mainly mature B cells) yielded hundreds of genes. We also examined the B cell-activating factor (BAFF)-dependent effects on immature splenic B cells by comparing expression patterns in the spleen between 2-week A/J vs 2-week A/WySnJ mice, which lack functional BAFF receptor signaling. Genes that showed the expression differences between spleen and bone marrow samples were then analyzed through quantitative PCR on B-cell subsets isolated using two different sorting protocols. A comparison of the results from our study with the results from other analyses showed not only some overlap of preferentially expressed genes but also an expansion of other genes potentially involved in B-cell development.

Duplications in the DMD gene.

The detection of duplications in Duchenne (DMD)/Becker Muscular Dystrophy (BMD) has long been a neglected issue. However, recent technological advancements have significantly simplified screening for such rearrangements. We report here the detection and analysis of 118 duplications in the DMD gene of DMD/BMD patients. In an unselected patient series the duplication frequency was 7%. In patients already screened for deletions and point mutations, duplications were detected in 87% of cases. There were four complex, noncontiguous rearrangements, with two also involving a partial triplication. In one of the few cases where RNA was analyzed, a seemingly contiguous duplication turned out to be a duplication/deletion case generating a transcript with an unexpected single-exon deletion and an initially undetected duplication. These findings indicate that for clinical diagnosis, duplications should be treated with special care, and without further analysis the reading frame rule should not be applied. As with deletions, duplications occur nonrandomly but with a dramatically different distribution. Duplication frequency is highest near the 5' end of the gene, with a duplication of exon 2 being the single most common duplication identified. Analysis of the extent of 11 exon 2 duplications revealed two intron 2 recombination hotspots. Sequencing four of the breakpoints showed that they did not arise from unequal sister chromatid exchange, but more likely from synthesis-dependent nonhomologous end joining. There appear to be fundamental differences therefore in the origin of deletions and duplications in the DMD gene.

Automated genomic sequence analysis of the three collagen VI genes: applications to Ullrich congenital muscular dystrophy and Bethlem myopathy.

INTRODUCTION: Mutations in the genes encoding collagen VI (COL6A1, COL6A2, and COL6A3) cause Bethlem myopathy (BM) and Ullrich congenital muscular dystrophy (UCMD). BM is a relatively mild dominantly inherited disorder with proximal weakness and distal joint contractures. UCMD is an autosomal recessive condition causing severe muscle weakness with proximal joint contractures and distal hyperlaxity. METHODS: We developed a method for rapid direct sequence analysis of all 107 coding exons of the COL6 genes using single condition amplification/internal primer (SCAIP) sequencing. We have sequenced all three COL6 genes from genomic DNA in 79 patients with UCMD or BM. RESULTS: We found putative mutations in one of the COL6 genes in 62% of patients. This more than doubles the number of identified COL6 mutations. Most of these changes are consistent with straightforward autosomal dominant or recessive inheritance. However, some patients showed changes in more than one of the COL6 genes, and our results suggest that some UCMD patients may have dominantly acting mutations rather than recessive disease. DISCUSSION: Our findings may explain some or all of the cases of UCMD that are unlinked to the COL6 loci under a recessive model. The large number of single nucleotide polymorphisms which we generated in the course of this work may be of importance in determining the major phenotypic variability seen in this group of disorders.

Enhancement of natural killer activity in human peripheral blood by flavone acetic acid.

Natural killer cell activity and interferon (IFN) production were measured in 6 patients receiving flavone acetic acid for treatment of cancer. Natural killer cell activity was significantly increased in 3 of 6 patients receiving 6.4 g of flavone acetic acid/m2 by 3-hour iv infusion. Analysis of cell surface markers failed to reveal significant changes in any cell population. There was no evidence of induction of IFN-gamma, but 3 of 4 patients tested had evidence of induction of type I IFN, as measured in a virus neutralization assay.

Cigarette smoking and risk of acute leukemia: associations with morphology and cytogenetic abnormalities in bone marrow.

BACKGROUND: Cigarette smoking may be a risk factor for leukemia. No detailed biological mechanism has been proposed, but a causal link is made plausible by evidence of systemic effects of cigarette smoke and the presence in cigarette smoke of chemicals that have been associated with leukemia risk. PURPOSE: Our purpose was to investigate the leukemia risk associated with cigarette smoking in a multicenter case-control study of acute leukemias in adults. METHODS: Adults aged 18-79 with newly diagnosed leukemia were contacted to participate in this epidemiologic study when they entered a clinical trial to be treated under protocols sponsored by Cancer and Leukemia Group B. Smoking histories for 610 patients with acute leukemia and 618 population control subjects were obtained by telephone interviews. We examined bone marrow samples and classified patients by morphology of leukocyte precursor cells according to the French-American-British (FAB) classification system and, for 378 patients, by the presence or absence of specific clonal chromosome abnormalities. We calculated odds ratios (ORs) for risk of leukemia associated with smoking cigarettes. ORs were adjusted for age, race, and sex. RESULTS: Smoking was associated with only a modest increase in risk for leukemia overall (adjusted OR = 1.13; 95% confidence interval [CI] = 0.89-1.44). However, among participants aged 60 and older, smoking was associated with a twofold increase in risk for acute myeloid leukemia (AML) (OR = 1.96; 95% CI = 1.17-3.28) and a threefold increase in risk for acute lymphocytic leukemia (ALL) (OR = 3.40; 95% CI = 0.97-11.9). Among older persons, risks increased with amount and duration of smoking. Smoking was associated with increased risk for AML classified as FAB type M2 at all ages, with ORs of 1.70 (95% CI = 1.00-2.90) for those younger than 60 and 3.50 (95% CI = 1.53-8.03) for those aged 60 and older. Smoking was also associated with ALL type L2 at all ages, with ORs of 1.72 (95% CI = 0.90-3.27) for those younger than 60 and 5.34 (95% CI = 1.03-27.6) for those who were older. Smoking was more common among patients with specific chromosome abnormalities in AML [-7 or 7q-, -Y, +13] and in ALL [t(9;22)(q34;q11)]. CONCLUSIONS: Cigarette smoking is associated with increased risk for leukemia and may lead to leukemias of specific morphologic and chromosomal types. The association varies with age. IMPLICATION: Examining discrete subtypes of disease may permit more accurate assessment of risk. As standardized morphologic classification and cytogenetic and molecular evaluation of leukemia patients becomes more common, epidemiologic studies that take advantage of these advances will begin to contribute to the identification of additional risk factors and mechanisms in acute leukemia.

Dose and dose intensity as determinants of outcome in the adjuvant treatment of breast cancer. The Cancer and Leukemia Group B.

BACKGROUND: Both total dose and dose intensity of adjuvant chemotherapy are postulated to be important variables in the outcome for patients with operable breast cancer. The Cancer and Leukemia Group B study 8541 examined the effects of adjuvant treatment using conventional-range dose and dose intensity in female patients with stage II (axillary lymph node-positive) breast cancer. METHODS: Within 6 weeks of surgery (radical mastectomy, modified radical mastectomy, or lumpectomy), 1550 patients with unilateral breast cancer were randomly assigned to one of three treatment arms: high-, moderate-, or low-dose intensity. The patients received cyclophosphamide, doxorubicin, and 5-fluorouracil on day 1 of each chemotherapy cycle, with 5-fluorouracil administration repeated on day 8. The high-dose arm had twice the dose intensity and twice the drug dose as the low-dose arm. The moderate-dose arm had two thirds the dose intensity as the high-dose arm but the same total drug dose. Disease-free survival and overall survival were primary end points of the study. RESULTS: At a median follow-up of 9 years, disease-free survival and overall survival for patients on the moderate- and high-dose arms are superior to the corresponding survival measures for patients on the low-dose arm (two-sided P<.0001 and two-sided P = .004, respectively), with no difference in disease-free or overall survival between the moderate- and the high-dose arms. At 5 years, overall survival (average +/- standard error) is 79% +/- 2% for patients on the high-dose arm, 77% +/- 2% for the patients on the moderate-dose arm, and 72% +/- 2% for patients on the low-dose arm; disease-free survival is 66% +/- 2%, 61% +/- 2%, and 56% +/- 2%, respectively. CONCLUSION: Within the conventional dose range for this chemotherapy regimen, a higher dose is associated with better disease-free survival and overall survival.

Phase I and clinical pharmacology study of intravenous flavone acetic acid (NSC 347512).

We have conducted a Phase I and pharmacological study of flavone acetic acid, one of a series of novel flavonoids. The drug was administered i.v. weekly for 4 weeks, with a 2-week rest and then repeated. Flavone acetic acid was given initially in a 1-h infusion, but at the 3900-mg/m2 dose level, the infusion time was lengthened to 3 h. A total of 31 patients were treated with 9 different dose levels, ranging from 330 to 6400 mg/m2. Dose-limiting toxicity was acute hypotension that began after about one-third of each drug dose had been infused and rarely lasted more than a few minutes after the infusion was discontinued. In addition, subjective fatigue and asthenia causing unacceptable patient discomfort was dose limiting. A significant side effect noted that was not dose limiting was diarrhea during the infusion. This drug exhibited nonlinear pharmacokinetic behavior. Plasma levels exceeded 300 micrograms/ml during the infusion at the maximally tolerated dose. After the infusion ended the principal half-life was about 2 h. In 24-h urine collections 27% of the flavone acetic acid dose was recovered as intact drug and an additional 37% was recovered as a metabolite. The maximally tolerated dose determined in this study is 6400 mg/m2 given i.v. over 3 h.

Phase I bioavailability and pharmacokinetic study of hexamethylene bisacetamide (NSC 95580) administered via nasogastric tube.

A Phase I clinical trial and pharmacological study of nasogastrically administered hexamethylene bisacetamide, a polar-planar compound with in vitro differentiating activity, was conducted in 14 adult patients with refractory cancer. Hexamethylene bisacetamide was administered as a 5% (w/v) solution via a nasogastric or gastrostomy tube every 4 h for 5 days, followed in 21 days by a 5-day continuous i.v. infusion at the same daily dose. Parenteral drug administration was then continued at the same interval in the absence of disease progression or unacceptable toxicity. Three patients each were treated at doses of 12 and 24 g/m2/day, while eight patients received a dose of 30 g/m2/day. Toxicity was comparable for both routes of drug administration at the above doses. Nasogastrically administered hexamethylene bisacetamide was well tolerated at the lower doses, whereas neurotoxicity and nausea and vomiting were the major, but manageable, toxicities at 30 g/m2/day. Metabolic acidosis, renal dysfunction, mucositis, and thrombocytopenia were the other commonly observed drug toxicities at this dose. No objective tumor responses were observed. Hexamethylene bisacetamide was rapidly absorbed from the gastrointestinal tract with a mean measured bioavailability of 99 +/- 15%. Pharmacokinetic parameters for hexamethylene bisacetamide and plasma concentrations of the two major metabolites, N-acetyl-1,6-diaminohexane and 6-acetamidohexanoic acid, were similar for either route of administration in individual patients. Hexamethylene bisacetamide exhibited apparent monoexponential plasma elimination after either nasogastric or parenteral administration with 27 to 60% of the administered dose being excreted in the urine as parent compound. Based on its demonstrated complete bioavailability and tolerability, nasogastric administration of hexamethylene bisacetamide can be directly and safely substituted for the comparable i.v. dose.

A phase I and pharmacokinetic study of diamminecyclobutane-dicarboxylatoplatinum (NSC 241240).

Carboplatin (CBDCA; NSC 241240) is a second-generation platinum coordination compound which in preclinical testing was found to be less nephrotoxic and emetogenic than cis-diamminedichloroplatinum (CDDP), while retaining a broad spectrum of antitumor activity. We have conducted a Phase I trial of CBDCA in 38 patients with advanced carcinoma. The drug was given without hydration as a 24-hr constant i.v. infusion on Day 1 of a 28-day cycle. Seventy-five cycles of CBDCA were administered in eight dose levels ranging from 20 to 320 mg/sq m. Dose-limiting toxicity was myelosuppression, primarily thrombocytopenia, occurring between Days 14 and 28 of the cycle. Myelosuppression was first observed at a dose of 240 mg/sq m and became dose-limiting at 320 mg/sq m, which is the recommended dose for Phase II trial. Other toxicities included nausea and vomiting and reversible renal failure seen in two patients with low normal pretreatment creatinine clearances. No consistent changes were seen on serial audiograms. Plasma concentrations of total and ultrafilterable platinum were measured by flameless atomic absorption spectrophotometry. Following cessation of the infusion, a half-life of 170 +/- 34 min (S.D.) was found for CBDCA-derived ultrafilterable platinum. In vitro clonogenic assay of a CDDP-sensitive human ovarian cancer cell line using clinically achievable drug concentrations suggests that prolonged infusions of CBDCA may be more cytotoxic than bolus administration. In this study, minimal responses were seen in two patients with ovarian carcinoma who had failed previous combination chemotherapy including CDDP. In addition, three patients with refractory metastatic breast cancer responded to CBDCA (two minimal responses and one partial response) with remission durations averaging 3 months. CBDCA behaves as predicted by preclinical studies with different toxicities from CDDP and apparent activity in breast cancer.

Neoplasia and the erythron.

Neoplasms may affect the erythroid system in a variety of ways. By far the most common abnormality associated with neoplastic disorders is anemia. It is important to recognize that there are multiple causes of anemia associated with neoplasms, because therapy of the anemia varies according to the causative mechanism. Less commonly, the paraneoplastic syndrome of erythrocytosis may occur in some patients with neoplasia. More subtle abnormalities of the erythrocytes associated with malignant disease include modification of the RBC membrane, changes in erythrocyte enzymes, and abnormalities in hemoglobin production. Clinical awareness of the multiple effects of neoplasms on the erythron will lead to better patient management and may also improve our understanding of erythropoiesis.

Mitomycin: ten years after approval for marketing.

Mitomycin was approved for marketing by the Food and Drug Administration in 1974 for use in gastric and pancreatic carcinomas when combined with other chemotherapeutic agents. Since then, mitomycin has been used extensively in combination chemotherapy for a variety of tumors, particularly in the past seven years. However, the contribution of this agent to the various drug regimens has not been adequately defined. Clear evidence of the drug's activity as a single agent has been seen in the intravesical treatment of superficial bladder carcinoma. Common toxicities include anorexia, vomiting, and myelosuppression. Less common, but potentially lethal, toxicities in the form of fibrosing alveolitis and microangiopathic hemolytic anemia with renal failure are being reported with increasing frequency. These potentially severe adverse effects, coupled with the still undefined role of mitomycin in systemic cancer chemotherapy, suggest that selection of this drug for other than investigational use should be made with care.

Cytarabine and neurologic toxicity.

Cytarabine is an effective drug in the treatment of certain hematologic malignancies and its common toxicities are myelosuppression and gastrointestinal disturbance. In the past decade, neurotoxicity has been an increasingly recognized cytarabine effect. Intrathecal (IT) cytarabine may result in myelopathy that is incompletely reversible. Combined IT drug and cranial irradiation may lead to necrotizing leukoencephalopathy. Intravenous (IV) therapy may cause a peripheral neuropathy that varies greatly in its severity. The high IV cytarabine doses now commonly used can cause seizures, cerebral dysfunction, or an acute cerebellar syndrome with an incidence up to 14%. Patient age (greater than 60 years) appears to be the most important risk factor, but drug dose/schedule, cumulative drug dose, renal and hepatic dysfunction, and concomitant use of neurotropic antiemetic agents may also influence the risk of neurotoxicity. A better understanding of the pathophysiology and pharmacology of such cytarabine-induced neuronal injury will allow this drug to be used with greater efficacy and safety.

An on-site audit of the South African trial of high-dose chemotherapy for metastatic breast cancer and associated publications.

PURPOSE: The randomized study reported by Bezwoda et al of high-dose chemotherapy (HDC) for treatment of metastatic breast cancer was audited on site to verify the study results. Additional published studies were reviewed to determine whether they had been subject to the required institutional oversight. PATIENTS AND METHODS: Ninety patients were reported to have been randomized and treated on this trial. A log of the names, hospital numbers, entry dates, and regimen received had been provided by the principal investigator. A search of more than 15,000 sets of medical records available from two Johannesburg hospitals was performed to locate records for as many of these 90 patients as possible. Standard auditing techniques were used. Additional clinical trials published by Bezwoda were compared against the minutes of the University of the Witwatersrand Committee for Research on Human Subjects to verify review and approval. RESULTS: Records for only 61 of the 90 patients could be found. Of these 61, only 27 had sufficient records to verify eligibility for the trial by the published criteria. Of these 27, 18 did not meet one or more eligibility criteria. Only 25 patients appeared to have received their assigned therapy temporally associated with their enrollment date, and all but three of these 25 received HDC. The treatment details of individual patients were at great variance from the published data. Nine other trials reported by Bezwoda were not reviewed or approved by the appropriate institutional committee despite statements to the contrary in the publications. CONCLUSION: The multiple publications of this study do not report verifiable data, and nine other publications coauthored by the principal investigator contain at least one major untrue statement.

Amsacrine-associated cardiotoxicity: an analysis of 82 cases.

Amsacrine is an antileukemia drug being widely used in North America, Europe, Australia, and New Zealand. In the initial clinical trials, patients treated with amsacrine developed occasional instances of acute cardiac arrhythmias and cardiomyopathy. We review and analyze the features of cardiac abnormalities associated with amsacrine in 82 patients, 27 of whom have not been previously reported. The rest have been reported in the literature, but we have included a large amount of additional information about these patients in our analysis. We conclude that amsacrine-related cardiac events are less common than those related to anthracycline chemotherapeutic agents. Manifestations of such toxicity include ECG abnormalities, ventricular and atrial arrhythmias, sudden death, and congestive heart failure. There is little or no cumulative dose effect. Hypokalemia may be a risk factor for development of serious tachyarrhythmias, but such problems can occur despite a normal serum potassium level. Amsacrine appears to affect depolarization and repolarization of the heart, but the mechanism is unknown.

Hemolytic anemia after fludarabine therapy for chronic lymphocytic leukemia.

PURPOSE: A report of the clinical features, treatment, and outcome of patients who developed hemolytic anemia (HA) temporally associated with fludarabine (Fludara; Berlex Laboratories, Richmond, CA) therapy for chronic lymphocytic leukemia (CLL). PATIENTS AND METHODS: Data on 24 patients who developed HA related to fludarabine therapy were collected from the Spontaneous Reporting System of the Food and Drug Administration (FDA) and the Walter Reed Army Medical Center (Washington, DC). RESULTS: Seventeen (71%) patients developed HA after either the first, second, or third cycle of this drug. The longest duration of fludarabine therapy before HA occurred was six cycles. The median decline in hematocrit from baseline during the hemolytic episode was 14.1 (range, 8.0 to 28.9) for the 18 patients for whom this information was available. For the 11 patients for whom transfusion requirements were known, the number of transfusions administered ranged between three and 36. Seven (29%) patients died of medical complications associated with the HA. Seven of eight patients who were re-challenged with fludarabine after an episode of HA developed recurrent HA, and three of these patients died. CONCLUSION: HA associated with fludarabine therapy appears to be uncommon, but it can be severe and fatal, especially if a patient is re-treated with this drug after a previous episode of HA. The mechanism of this toxicity is unknown, but it may be caused by the release of a suppressed auto-antibody to a native red cell antigen.

No evidence of acute cardiovascular complications of chemotherapy for testicular cancer: an analysis of the Testicular Cancer Intergroup Study.

PURPOSE: The purpose of this study is to evaluate the risk of acute vascular events in patients receiving cisplatin-based chemotherapy for testicular cancer. PATIENTS AND METHODS: A questionnaire assessing cardiovascular toxicity was distributed to all participants in the Testicular Cancer Intergroup study and details of toxicity from the chemotherapy flow sheets were reviewed. Patients with pathologic stage I testicular cancer were registered on to the study and observed after retroperitoneal lymphadenectomy. Patients with pathologic stage II disease were randomized to receive two postoperative courses of adjuvant cisplatin-based chemotherapy or observation. Any patient who had disease recurrence after observation or adjuvant therapy was given four cycles of cisplatin-based chemotherapy. RESULTS: Review treatment-related toxicity for those patients receiving adjuvant chemotherapy (n = 97) or chemotherapy for recurrent disease (n = 83) showed no cases of acute cardiovascular toxicity. The median follow-up period after study enrollment was 5.1 years; 459 questionnaires were mailed and 270 were returned. The percent return was equal among the observed adjuvant and recurrent groups (59%, 54%, and 64%). There was a significant increase in the incidence of extremity paresthesias in the two groups receiving chemotherapy. Fatal myocardial infarction was reported in two patients in the observation group and one nonfatal infarction was reported in the adjuvant treatment group. No patient in any group reported an incidence of stroke. Three patients in the observation group and one patient in the recurrent group experienced a thromboembolic event. CONCLUSION: Despite sporadic case reports suggesting a causal association between chemotherapy for testicular cancer and acute vascular events, this retrospective analysis provides no evidence of an increased risk for subsequent cardiovascular disease in this patient population.

Prognosis and other clinical correlates of pathologic review in stage I and II testicular carcinoma: a report from the Testicular Cancer Intergroup Study.

PURPOSE: The Testicular Cancer Intergroup Study (TCIS) was undertaken to evaluate the pathologic findings in early-stage testicular cancer as determined by central pathology review, to compare these findings with the interpretation by the contributing pathologists, and to make correlations with various clinical parameters and outcomes. PATIENTS AND METHODS: The prospective study of non-seminomatous germ cell testicular cancer staged surgically involved 459 eligible patients with stage I (node-negative) or stage II (node-positive) disease. Pathologic materials from both the orchiectomy and lymphadenectomy specimens were submitted to a central laboratory for evaluation. RESULTS: Central and local pathologists differed significantly in their identification of certain cellular histologies (primarily yolk sac tumors [YST]) and recognition of invasion into vascular structures. In contrast to our prior findings with local pathologic assessment, venous/lymphatic invasion as determined by central review predicted relapse in both stages. In pathologic stage I disease, the relapse rate was 19.4% (12 of 62 cases) for those with invasion versus 6.0% (10 of 168 cases) for those without invasion. In pathologic stage II disease, the respective relapse rates were 63.5% (40 of 63 cases) and 24.0% (six of 25 cases). Vascular invasion was jointly predictive with nodal stage for risk of relapse. The percentage of embryonal carcinoma (EC) in the primary tumor was predictive of nodal stage and relapse in a univariate, but not a multivariate, analysis. In a large substudy, immunohistochemical staining identified a correlation between stain intensity in YST and serum alpha-fetoprotein (AFP) levels. In a similar fashion human chorionic gonadotropin (HCG) staining reactivity occurred exclusively in patients with syncytiotrophoblasts and correlated with serum levels of beta-HCG. CONCLUSIONS: A number of tumor histology correlates with clinical parameters have been identified or confirmed. Careful pathologic scrutiny of the primary testicular tumor, especially for vascular invasion, provides important prognostic information.

Prediction of prognosis in primary breast cancer by detection of a high molecular weight mucin-like antigen using monoclonal antibodies DF3, F36/22, and CU18: a Cancer and Leukemia Group B study.

Three monoclonal antibodies (MAbs) (DF3, F36/22, CU18) were used to monitor expression of distinct epitopes present within a family of mucin-like, breast carcinoma-associated molecules. Primary tumor specimens from more than 190 stage II breast cancer patients were evaluated for expression of the high molecular weight antigens. With a median follow-up of 6 years, patients whose tumors exhibited high immunoperoxidase staining scores (greater than 50% positive cells) with MAb DF3 had a superior disease-free survival ([DFS] 56% +/- 6% v 37% +/- 5% at 6 years; P = .0088) and overall survival ([OS] 72% +/- 5% v 59% +/- 5% at 6 years; P = .025). Staining scores with the other two antibodies did not correlate with improved prognosis. For MAbs DF3 and CU18, patients whose tumors exhibited predominantly apical cellular reactivity patterns had improved DFS, although differences reached conventional levels of statistical significance only with MAb CU18. In multivariate analyses, the prognostic value of MAb DF3 staining was independent of other identified prognostic factors. Furthermore, the concordance between primary and axillary lymph node metastases staining with each MAb was 73%, 80%, and 85% for MAbs DF3, F36/22, and CU18, respectively. These results suggest that staining with MAb DF3 identifies a group of node-positive women with a relatively favorable prognosis. Expression of the DF3 mucin-like glycoprotein is related to better differentiation, and staining with MAb DF3 provides an accurate and objective estimate of clinical outcome independent of histopathologic evaluation.

Relationship between toxicity and obesity in women receiving adjuvant chemotherapy for breast cancer: results from cancer and leukemia group B study 8541.

PURPOSE: We examined data from a large clinical trial to determine if chemotherapy dosing according to actual body weight places obese patients at greater risk of toxicity. PATIENTS AND METHODS: Cancer and Leukemia Group B (CALGB) study 8541, a randomized study of schedule and dose of adjuvant cyclophosphamide, doxorubicin, and fluorouracil (CAF) for stage II breast cancer patients with positive regional lymph nodes, provided data on 1,435 women for analysis. Using body-mass index (BMI), we classified a woman as obese if her BMI was > or = 27.3 kg/m2; doses were considered weight-based if within 5% of values calculated using actual weight. Our primary analysis concerned toxicity risks during cycle 1. RESULTS: Among women who received weight-based doses of the most dose-intensive CAF regimen, 47% of obese and 51% of nonobese women experienced severe hematologic toxicity (grade > or = 3) during cycle 1 (P = .51, two-tailed). The overall risk ratio (obese v nonobese) of treatment failure among women who received weight-based doses during cycle 1 was 1.02 (95% confidence interval, 0.83 to 1.26), stratified by treatment and adjusted for number of positive nodes, menopausal status, hormone receptor status, and tumor size. The overall adjusted failure risk ratio (weight-based v reduced initial doses) was 0.73 (95% confidence interval, 0.53 to 1.00) among obese women. CONCLUSION: Obese patients initially dosed (within 5%) by actual weight did not experience excess cycle 1 toxicity or worse outcome compared with nonobese women dosed similarly. The data suggest that obese women who received reduced doses in cycle 1 experienced worse failure-free survival. We recommend that initial doses of CAF be computed according to actual body weight.