Smoking-attributable cancer mortality in 1991: is lung cancer now the leading cause of death among smokers in the United States?

Findings from the new American Cancer Society prospective study of 1.2 million men and women indicate that mortality risks among smokers have increased substantially for most of the eight major cancer sites causally associated with cigarette smoking. Lung cancer risk for male smokers doubled, while the risk for females increased more than fourfold. On the basis of the new American Cancer Society relative risks, we project that cigarette smoking alone will contribute to slightly more than 157,000 of the 514,000 total cancer deaths expected to occur in the United States in 1991. Overall, smoking directly contributes to 21.5% of all cancer deaths in women but 45% of all cancer deaths in men. It would also appear that lung cancer has now displaced coronary heart disease as the single leading cause of excess mortality among smokers in the United States.

Two novel mucin genes down-regulated in colorectal cancer identified by differential display.

Epithelial mucins are large, secreted and cell surface glycoproteins involved in epithelial cell protection, adhesion modulation, and signaling. Using differential display, we have identified two novel mucin cDNAs (dd34 and dd29), hereafter designated MUC11 and MUC12, respectively, that are down-regulated in colorectal cancers. Northern blots demonstrated polydisperse signals characteristic of mucin transcripts in RNA from normal colon that were absent in colorectal cancer. Both cDNAs were mapped by fluorescence in situ hybridization to chromosome band 7q22, the location of the MUC3 mucin gene, thus suggesting that there may be a cluster of mucin genes at this locus. The sequences of both differential display clones were extended by a combination of screening libraries and PCR. The 2.8-kb MUC11 cDNA composite encoded 35 serine/threonine-rich, mucin-like degenerate 28 amino acid tandem repeats. The MUC12 cDNA composite encoded a putative transmembrane mucin containing two extracellular cysteine-rich, EGF-like domains, a coiled-coil region, and a mucin-like domain consisting of 28 amino acid degenerate tandem repeats. Distinct patterns of expression of MUC11, MUC12, and MUC3 mRNAs were observed in a range of normal human tissues. MUC12 mRNA was not expressed in any of six colorectal cancer cell lines examined and was down-regulated or absent in 6 of 15 (40%) tumors compared with matched normal colonic tissue. In contrast, MUC11 showed a different pattern of mRNA expression, with four of these lines showing low levels and the other two lines showing relatively high levels of MUC11 transcripts. Expression of MUC11 was down-regulated in the tumors of 12 of 15 (80%) paired samples. Structural homology of MUC12 with rat, mouse, and human MUC3 and human and rat MUC4/ASGP2 indicate that there is a distinct subfamily of transmembrane mucins with conserved epidermal growth factor domains. The homology of MUC12 with epidermal growth factor-like growth factors and its down-regulation in colorectal cancers, together with known interactions between rat MUC4 and c-erbB-2 growth factor receptors, suggests that MUC12 may be involved in epithelial cell growth regulation.

Testisin, a new human serine proteinase expressed by premeiotic testicular germ cells and lost in testicular germ cell tumors.

We have cloned and characterized a cDNA encoding a new human serine proteinase, testisin, that is abundantly expressed only in the testis and is lost in testicular tumors. The testisin cDNA was identified by homology cloning using degenerate primers directed at conserved sequence motifs within the catalytic regions of serine proteinases. It is 1073 nucleotides long, including 942 nucleotides of open reading frame and a 113-nucleotide 3' untranslated sequence. Northern and dot blot analyses of RNA from a range of normal human tissues revealed a 1.4-kb mRNA species that was present only in testis, which was not detected in eight of eight testicular tumors. Testisin cDNA is predicted to encode a protein of 314 amino acids, which consists of a 19-amino acid (aa) signal peptide, a 22-aa proregion, and a 273-aa catalytic domain, including a unique 17-aa COOH-terminal hydrophobic extension that is predicted to function as a membrane anchor. The deduced amino acid sequence of testisin shows 44% identity to prostasin and contains features that are typical of serine proteinases with trypsin-like substrate specificity. Antipeptide antibodies directed against the testisin polypeptide detected an immunoreactive testisin protein of Mr 35,000-39,000 in cell lysates from COS-7 cells that were transiently transfected with testisin cDNA. Immunostaining of normal testicular tissue showed that testisin was expressed in the cytoplasm and on the plasma membrane of premeiotic germ cells. No staining was detected in eight of eight germ cell-derived testicular tumors. In addition, the testisin gene was localized by fluorescence in situ hybridization to the short arm of human chromosome 16 (16p13.3), a region that has been associated with allellic imbalance and loss of heterozygosity in sporadic testicular tumors. These findings demonstrate a new cell surface serine proteinase, loss of which may have a direct or indirect role in the progression of testicular tumors of germ cell origin.

Gamma-heregulin: a fusion gene of DOC-4 and neuregulin-1 derived from a chromosome translocation.

gamma-Heregulin was identified as an isoform resulting from alternate splicing of the neuregulin-1 gene, after cloning of its cDNA from the MDA-MB-175 breast cancer cell line. gamma-Heregulin was shown to promote growth of cultured MDA-MB-175 cells resulting from activation of its cognate ErbB tyrosine kinase reporters. We show here that gamma-heregulin is transcribed from a fusion gene resulting from a chromosome translocation in MDA-MB-175 cells. The fusion chromosome is described as dic(8:11)(8qter-->8p12::11q13-->11pter). As a result, the 5' end of the gamma-heregulin gene is derived from the stress-induced gene, DOC-4 (11q13), while the 3' end is from the neuregulin-1 gene (8p12). Thus, expression of gamma-heregulin is under the control of the DOC-4 promoter. By contrast with MDA-MB-175 cells, RT-PCR failed to detect a gamma-heregulin transcript in either E9.5 to E13.5 embryonic mouse tissues, adult mouse tissues or other human tumour cell lines. We conclude, therefore, that gamma-heregulin is not a native isoform of the neuregulin-1 gene, but a novel growth factor that may contribute to tumour cell proliferation.

A novel epithelial-expressed ETS gene, ELF3: human and murine cDNA sequences, murine genomic organization, human mapping to 1q32.2 and expression in tissues and cancer.

The ETS family of genes are implicated in cancers such as Ewings sarcoma, acute myeloid leukemia and chronic myelomonocytic leukemia. Further, they have important functions in embryonic development. Hence, identification and characterization of members of this family are important. We identify a novel ETS family member, ELF3, and report its human and murine cDNA sequences. The mouse cDNA has an alternatively spliced transcript with an extra 60 bp inserted. Hence we present the organization of the murine Elf3 gene together with its exon/intron structure. This gene consists of 9 exons and 8 introns spanning 4.8 kb. ELF3 binds and transactivates ETS sequences and interestingly also shows the ability to bind a GGAT-like purine core, a preferential ETS1/ETS2 type binding site. The expression of ELF3, unlike most other ETS family members, is absent in hematopoietic cells and hematopoietic organs in humans and mice. Intriguingly, the gene is specifically expressed in cell lines of epithelial origin and in organs such as lung, stomach, intestine, kidney that have specialized epithelial cells. We localize the human gene to 1q32.2, a region that is amplified in epithelial tumors of the breast, lung and prostate. Finally, we show that ELF3 expression is increased in a lung carcinoma and adenocarcinoma, as compared to normal tissue. ELF3 is also expressed in cell lines derived from lung cancers. These results suggest that this novel ETS gene may be involved in lung tumorigenesis.

Y-receptor-like genes GPR72 and GPR73: molecular cloning, genomic organisation and assignment to human chromosome 11q21.1 and 2p14 and mouse chromosome 9 and 6.

Two novel G-protein-coupled receptors, one from human, GPR72, and one from mouse, GPR73 have been isolated, sequenced and their genomic organisation determined. Non-isotopic in situ hybridisation and radiation hybrid mapping have identified GPR72 to be localised on human chromosome 11q21.1, and GPR73 on human chromosome 2p14. Interspecific mouse backcross mapping has localised the genes to mouse chromosomes 9 and 6, respectively. Northern analysis reveals GPR72 mRNA expression only in brain tissue. However, GPR73 mRNA can be found in heart, skeletal muscle and pancreas. Both receptors are closely related with 36 and 33% overall amino acid identity, respectively, to the Y-receptor family. However, although successful cell surface expression in a heterologous expression system can be achieved no specific binding to this ligand family can be detected, indicating that perhaps additional factors are required for binding.

Effect of initial resection of small-cell carcinoma of the lung: a review of Southwest Oncology Group Study 7628.

The role of surgery in small-cell carcinoma of the lung (SCCL) has been recently re-evaluated. We reviewed the records of 262 patients with limited SCCL on Southwest Oncology Group (SWOG) protocol 7628. Fifteen patients were identified who presented after surgical resection (12 lobectomy, three pneumonectomy). All patients were subsequently treated with chemotherapy, radiotherapy +/- immunotherapy (BCG). Median survival time was 10.5 months. Median survival time of patients with initial surgical resection was 25 months (P = .004). Forty-five percent of the surgical patients were alive at two years v 13.7% of the nonsurgical patients (P less than .05). A second subgroup of 33 patients was identified with small primary tumors who did not undergo surgical resection. Median survival time in this group was ten months (P = .03). Site of initial relapse was clearly documented in 142 patients. Fifty-six percent of patients not receiving surgery had initial relapse within the chest compared to 13% of patients undergoing surgery (P = .002). Whether the survival benefit identified was caused by or was incidental to surgical resection of the primary lesion remains to be determined in randomized prospective trials of operable candidates.

Objective antitumor activity of acivicin in patients with recurrent CNS malignancies: a Southwest Oncology Group trial.

Acivicin (AT-125) is a glutamine antagonist with dose-limiting, schedule-dependent CNS toxicity and predictable CSF penetration after intravenous administration. Because of these properties, a trial in CNS malignancies was initiated. Thirty-two patients with recurrent or residual malignant astrocytomas were treated with AT-125. The majority of patients had glioblastoma multiforme (24) and had received prior nitrosoureas (21). The median age was 50 years, and Southwest Oncology Group (SWOG) performance status was 2. The major determinant of response was based upon radiologic criteria using computed tomographic (CT) scanning and/or magnetic resonance imaging (MRI) scans. The tumor mass was measured in two perpendicular planes, which yielded the largest cross-sectional area. Standard solid tumor criteria for response were used. All responding patients also had a stable or tapered dose of corticosteroids with stable or improved performance status and neurologic examination. There were four objective responses (12%): one complete remission (3 1/2+ years) and three partial remissions (57, 86, and 322 days). Two patients had improvement in disease that did not meet requirements for a partial remission. Toxicity was mild and primarily consisted of nausea, vomiting, and lethargy. Two patients were removed from study due to neurotoxicity (depression and hallucinations). The strict response criteria used in this trial were not those that have been used in testing other active agents such as carmustine (BCNU). We conclude that AT-125 has objective antitumor activity in malignant astrocytomas and warrants further study.

Unfavorable histologies of non-Hodgkin's lymphoma treated with ProMACE-CytaBOM: a groupwide Southwest Oncology Group study.

Chemotherapy using cyclophosphamide, doxorubicin, etoposide, cytarabine, bleomycin, vincristine, methotrexate with leucovorin, and prednisone (ProMACE-CytoBOM) for patients with intermediate- and high-grade non-Hodgkin's lymphomas was tested by the Southwest Oncology Group (SWOG) to confirm the activity of the regimen and to test the feasibility and safety of administering third-generation drug regimens in a cooperative group setting. On day 1, cyclophosphamide, doxorubicin, and etoposide were administered, followed by cytarabine, bleomycin, vincristine and methotrexate with leucovorin given on day 8. There were 51 complete remissions (CRs) among 78 previously untreated patients (65%) having clinical stage II-IV disease. The median length of follow-up is 37.9 months with 57% of patients alive at 3 years and 50% of CR patients free of disease at 3 years. Patients with diffuse large-cell lymphoma have the best survival (63% at 3 years) and relapse-free survival (RFS; 68% at 3 years with no relapses seen after 14 months). Administration of ProMACE-CytoBOM is feasible and safe in a cooperative group setting with 84% of 537 courses of treatment given exactly according to schedule and fatal toxicities seen in five patients (6%). ProMACE-CytaBOM may represent improved treatment for diffuse large-cell lymphoma, but the modest differences compared with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) indicate the need for a prospective randomized comparative trial.

Chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisone alone or with levamisole or with levamisole plus BCG for malignant lymphoma: a Southwest Oncology Group Study.

Between 1977 and 1983 the Southwest Oncology Group (SWOG) evaluated chemotherapy alone (cyclophosphamide, doxorubicin, vincristine, prednisone; CHOP) or chemoimmunotherapy (CHOP-levamisole or CHOP-levamisole-BCG) in a randomized prospective clinical trial involving 715 eligible patients with all types of malignant lymphoma (ML). Of 281 evaluable patients with favorable histologic types of ML, 171 (61%) achieved complete remission (CR) and there was no difference in CR rate, CR duration, or survival according to the type of initial treatment. Of 388 evaluable patients with unfavorable histologic types of ML, 194 (50%) achieved CR. Levamisole appeared to adversely affect CR rates in nodular mixed and nodular large-cell lymphoma and CR duration in patients with unfavorable histology ML. Chemoimmunotherapy with levamisole or levamisole-BCG offers no advantage in terms of CR rates, CR duration, or survival compared to CHOP chemotherapy alone, and levamisole may have had an adverse impact on outcome in certain subtypes of ML.

Correlation of tumor O6 methylguanine-DNA methyltransferase levels with survival of malignant astrocytoma patients treated with bis-chloroethylnitrosourea: a Southwest Oncology Group study.

PURPOSE: Prior studies show that increased levels of the DNA repair protein O6 methylguanine-DNA methyltransferase (MGMT), also referred to as O6-alkylguanine-DNA alkyltransferase (AGT) correlate with the resistance of glioma cell lines to nitrosoureas. The observed nitrosourea sensitivity of MGMT-deficient lines (methyl excision repair negative [MER-]) and those repair-proficient lines pretreated with MGMT-specific inhibitors (eg, O6 benzylguanine) has raised the possibility that tumor MGMT levels may be an important predictor of survival in patients with gliomas. PATIENTS AND METHODS: We correlated the MGMT level in malignant astrocytoma tissues, obtained from patients treated with radiotherapy and bis-chloroethylnitrosourea (BCNU) on a prior prospective trial (Southwest Oncology Group [SWOG] 8737), with overall and failure-free survival. RESULTS: Of 64 assessable patients with malignant astrocytoma (63% glioblastoma, 37% anaplastic astrocytoma), 64% had high (> 60,000 molecules/nucleus) MGMT levels. The overall median survival for patients with high versus low MGMT levels was 8 and 29 months, respectively (P=.0002), and median failure-free survival 3 and 6 months, respectively (P=.008). Subset analysis by histology (high v low MGMT levels) for anaplastic astrocytoma was 14 versus 62 months (n=24) and for glioblastoma was 7 versus 12 months (n=40). The overall hazards ratio (risk for death) for high versus low MGMT levels was 3.41; in young patients, the hazards ratio was higher (age 18 to 40 years, 4.19; age 41 to 60 years, 3.08) but became equal by MGMT level at age older than 60 years (1.11). Multivariate analysis showed that MGMT was independent of other known prognostic factors (age, performance status, histology). CONCLUSION: The MGMT level in tumor tissue specimens may be a predictive marker of survival in patients with malignant astrocytoma that is independent of other previously described prognostic variables.

A prospective evaluation of the roles of allogeneic marrow transplantation and low-dose monthly maintenance chemotherapy in the treatment of adult acute myelogenous leukemia (AML): a Southwest Oncology Group study.

Between February 1982 and December 1986, the Southwest Oncology Group conducted a prospective study in patients with newly diagnosed acute myeloid leukemia (AML) with two objectives: to evaluate the role of allogeneic marrow transplantation for patients in first remission, and to evaluate the role of low-dose monthly maintenance therapy in those patients not transplanted in first remission. Among 522 evaluable patients, 295 (57%) achieved complete remission (CR), including 70% of patients age 49 or less. Twenty-four patients (15%) age 49 or less in CR were not HLA-typed, mostly because of financial constraints. HLA-identical donors were found for 39% of patients, of whom two-thirds were transplanted in first CR. The 5-year disease-free survival among those transplanted in first CR, those with donors not transplanted in first CR, and those less than age 50 without donors was 41, 42, and 29%, respectively (P = 0.60). A total of 150 eligible patients were randomized to receive late intensification alone or late intensification plus monthly maintenance. In multivariate analyses, treatment with maintenance was associated with prolonged disease-free survival (P = 0.028), but not improved overall survival (P = 0.27). Factors associated with improved overall survival included younger age, lower white blood count (WBC) at diagnosis, having leukemia of M3 morphology, and being of white race. In this study, a diagnosis of M3 AML was particularly favorable, with disease-free and overall survivals of 75 and 56%, respectively, at 7 years.

Mapping of the trichohyalin gene: co-localization with the profilaggrin, involucrin, and loricrin genes.

The chromosomal location of the gene encoding the human hair follicle protein trichohyalin has been determined by in situ hybridization. The human gene has been localized to the region 1q21.1-1q23 (probably 1q21.3) using a sheep trichohyalin cDNA probe. The genes encoding three other epithelial proteins, namely, profilaggrin, involucrin, and loricrin, are also located in the same region of chromosome 1, which, together with their similar gene and protein structures, suggests that the four proteins form a novel superfamily of epithelial structural proteins.

Molecular cloning and characterization of a cDNA encoding the human leucocyte vacuolar protein sorting (h1Vps45).

We have isolated a novel cDNA clone from human leucocyte cDNA library, encoding a Sec1p-like vacuolar protein sorting (h1Vps45) which is believed to be implicated in vesicular transportation. Although the deduced amino acid (AA) sequence of this cDNA has revealed 97% identity to other known mammalian vacuolar protein sorting, there is an extensive variation in nucleotide sequence in comparison to that of three previously reported human (hVps45), rat (rVps45) and mouse (mVps45) vacuolar protein sorting (Vps45) cDNAs [1-3]. At the nucleotide sequence level h1Vps45 demonstrated 90% homology to the hVps45 and rVps45 and 89% identity to mVps45 with no significant homology in their noncoding regions. The 2.4 Kb mRNA corresponding to the h1Vps45 clone is widely distributed in a variety of human tissues expressing highest levels in peripheral blood mononuclear cells (PBMC), neutrophils, heart, spleen, and testis. The chromosomal mapping studies have demonstrated that the h1Vps45 is localized to long arm of human chromosome 1 at q21-q22. Our data indicates that we have isolated, characterized and mapped a novel cDNA encoding h1Vps45, which may play an important role in protein trafficking as well as have clinical significance in the release of inflammatory mediators e.g. histamine, bradykinin and cytokine release.

Complex organisation of the 5'-end of the human glycine tRNA synthetase gene.

Glycine tRNA synthetase (glyRS) catalyses the addition of the amino acid glycine to its cognate tRNA molecules. In the silk moth worm Bombyx mori, this gene is subject to complex transcriptional regulation because of the predominance of glycine in silk. In vertebrates, glycine is a major constituent of collagen but there have been no studies of glyRS regulation. In this study we have isolated and mapped a genomic clone containing the 5'-end of glyRS. Primer extension studies identified only one transcriptional start point (TSP) in three different cell lines. Expression of the transcript identified may be regulated translationally because it contains five potential initiation codons, three of which are in good context for initiation. The most 3' of the potential initiation codons has previously been predicted to be the initiating codon for cytoplasmic glyRS. Two of the upstream codons are in-frame with this codon, and both are predicted to extend the N-terminus of glyRS to include a mitochondrial targeting sequence. Sequencing of genomic DNA surrounding the TSP showed features common to the promoters of housekeeping genes, as well as a canonical TATA box at the unusual position of +9. Surprisingly, promoter activity in vitro was not specified by a 1.9 kb genomic fragment containing the TSP and TATA box, but by a contiguous 0.4 kb fragment immediately downstream. These studies suggest that the transcription of glyRS from a single start point requires downstream promoter elements.

Evaluation of the response of unresectable carcinoid tumors to radiotherapy.

Sixteen patients with unresectable primary or metastatic carcinoid tumors were treated with radiotherapy. Objective responses (CR + PR) were documented in 4 of 16 patients (25%). The median survival of the responders was 46 months following radiotherapy, as compared to the 10-month median survival of the entire group of 16 patients. There were five additional patients who improved symptomatically or had minor responses. The seven patients who received the highest doses of radiotherapy (greater than 29 GY), to local or regional treatment ports, had the best response rate (43%). Many patients eventually had objective evidence of relapse or tumor progression within the radiotherapy port, in part reflecting the relatively low radiotherapy doses used in the treatment of the nine patients with abdominal carcinoids. One patient remains disease free at 103 months. Patients who exhibited the carcinoid syndrome appeared to respond less frequently to radiotherapy than patients who did not have ectopic hormone secretion, although the number of patients with ectopic hormone secretion was too small to establish this point in a definitive manner. The results of this study demonstrate that carcinoid tumors respond to moderate doses of radiotherapy in a manner similar to many other epithelial tumors.

High resolution characterization of an interstitial deletion of less than 1.9 Mb at 4p16.3 associated with Wolf-Hirschhorn syndrome.

Wolf-Hirschhorn syndrome (WHS) caused by 4p16.3 deletions comprises growth and mental retardation, distinct facial appearance and seizures. This study characterized a subtle interstitial deletion of 4p16.3 in a girl with mild retardation and possessing facial traits characteristic of WHS. The patient had generalized seizures in conjunction with fever at 3 and 5 years of age. Fluorescence in situ hybridization (FISH) with a series of markers in the 4p16.3 region showed that the interstitial deletion in this patient was between the probes D4S96 and D4S182, enabling the size of the deletion to be estimated as less than 1.9 Mb. This is the smallest interstitial deletion of 4p16.3 which has been reported. The patient contributes to a refinement of the phenotypic map of the WHS region in 4p16.3. The critical region for the characteristic facial changes of WHS, failure to thrive and developmental delay is now localized to a region of less than 700 kb. The mental retardation of this patient was mild suggesting that small interstitial deletion may have less severe phenotypic consequences.

Molecular cloning and characterisation of GPR74 a novel G-protein coupled receptor closest related to the Y-receptor family.

A novel gene product, GPR74, with homology to the seven transmembrane-domain receptor superfamily, has been cloned. GPR74 has been identified from the expressed sequence tags (EST) database. Subsequent PCR amplification of that sequence and screening of a human heart cDNA library led to the isolation of a 1.7-kb cDNA clone encoding a protein of 408 amino acids. GPR74 shows highest amino acid identity (33%) to the human neuropeptide Y-receptor subtype Y2. The human and mouse genes for GPR74 have been isolated and their exon-intron structures determined. In both species the gene consists of four exons spanning around 20 kb with the exon-intron borders being 100% conserved. Northern analysis of various human tissues reveals highest levels of mRNA expression in brain and heart. In situ hybridisation analysis of rat brain tissue confirms this result and identifies the hippocampus and amygdala nuclei as the brain areas with particular high expression of GPR74 mRNA. Fluorescence in situ hybridisation, PCR analysis on a radiation hybrid panel and interspecific mouse backcross mapping have localised the genes to human chromosome 4q21 and mouse chromosome 5. Expression of the human GPR74 cDNA as a GFP-fusion protein in various cell lines reveals the inability of the recombinant receptor protein to reach the cell surface. This is consistent with the lack of NPY specific binding in these cells and suggests that unknown factors are required for a full functional receptor complex.

The biological significance of the multidrug resistance gene MRP in inversion 16 leukemias.

Multidrug resistance represents an important mechanism by which leukaemic and solid tumour cells escape cell death after exposure to anthracyclines and other natural products. Acute myeloid leukaemia (AML) associated with the inversion chromosome 16: inv(16)(p13q22) has a favourable prognosis and is known to be chemosensitive. The inversion chromosome is seen in a number of FAB subclasses but is most commonly associated with acute myelomonocytic leukaemia with abnormal eosinophils, M4Eo. It results in the creation of a fusion between the myosin heavy chain gene (MYH11) on the short arm and the gene for a transcription factor, core binding factor beta (CBFB) on the long arm. In a subset of these inv(16) AML patients, inversion also results in loss of the gene for the multidrug resistance protein (MRP) at the short arm breakpoint. This gene maps to 16p13.13, centromeric to the primary short arm breakpoint, separated from MYH11 by a distance of approximately 150kb. Deletion of the MRP gene has been demonstrated by in situ hybridisation, gene dosage studies and by loss of heterozygosity of a flanking microsatellite marker (D16S405). Twenty two patients with inv(16) leukaemia were analysed for deletion of the MRP gene. Deletion of the gene was detected in seven patients, fourteen patients showed retention of the gene and in one case the findings were indeterminate. Clinical data from 13 of these patients were analysed revealing deletion of the MRP gene to be significantly associated with longer time from diagnosis until failure (death or relapse from complete remission) in these patients (p = 0.007). From this work and the growing literature concerning MRP, it appears likely that the deletion of an MRP allele, may favourably affect the biology of inv(16) AML and may have important prognostic implications.

A randomized trial of radiotherapy versus radiotherapy plus CCNU for incompletely resected low-grade gliomas: a Southwest Oncology Group study.

Sixty adult patients with incompletely excised low-grade gliomas were randomly assigned to receive radiotherapy (55 Gy over a total of 6 1/2 to 7 weeks) either alone or with 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU; 100 mg/sq m every 6 weeks). Pathological review showed that six patients were ineligible for the study. Evaluation of patient age, extent of surgery, tumor grade, and performance status showed no significant differences between the treatment arms. The response rate, as judged by the disappearance or reduction in size of the tumor on computerized tomography scans, was 79% for radiation therapy alone versus 54% for irradiation plus CCNU. The median survival time was 4.45 years for all patients, with no significant difference between treatment arms (p = 0.7). For the group as a whole, patient age and performance status were the most important prognostic parameters. The majority of patients receiving chemotherapy experienced moderate hematological toxicity. This study demonstrates that CCNU chemotherapy does not improve the results of radiation therapy in the treatment of incompletely excised low-grade gliomas.