Opting into breast screening over the age of 70 years: seeking evidence to support informed choice.

AIM: To provide evidence specific to the Scottish population regarding the risk-benefit balance of women >70 years opting into continued breast screening, which may be used as a basis for patient information documentation. MATERIALS AND METHODS: The present study consisted of a parallel, retrospective data analysis of breast cancer mortality data for breast cancer cases diagnosed between 2009 and 2013 (n=22,013) followed up to 31/12/18, and breast screening programme data from 2010 and 2015 (n=47,235). Screening outcome measures included recall for assessment, oncome of assessment, and tumour features. Tumours were classified as high, intermediate, or low risk according to grade and presence of invasion. Mortality data were linked to age at diagnosis and cause of death was recorded. RESULTS: The proportion of all deaths due breast cancer is inversely related to age at diagnosis. From 77 years, women are more likely to die with breast cancer, than directly due to breast cancer. Mammographic screening accurately identifies breast cancer in older women; however, many of the cancers detected were considered intermediate or low risk. CONCLUSIONS: Harms may outweigh the benefits of continued breast screening in older women. This information should be available to all older women.

Maternal high-fat diet impacts endothelial function in nonhuman primate offspring.

OBJECTIVE: The link between maternal under-nutrition and cardiovascular disease (CVD) in the offspring later in life is well recognized, but the impact of maternal over-nutrition on the offspring's cardiovascular function and subsequent risk for CVD later in life remains unclear. Here, we investigated the impact of maternal exposure to a high-fat/calorie diet (HFD) during pregnancy and early postnatal period on endothelial function of the offspring in a nonhuman primate model. METHODS: Offspring, naturally born to either a control (CTR) diet (14% fat calories) or a HFD (36% fat calories) consumption dam, were breast-fed until weaning at about 8 months of age. After weaning, the offspring were either maintained on the same diet (CTR/CTR, HFD/HFD), or underwent a diet switch (CTR/HFD, HFD/CTR). Blood samples and arterial tissues were collected at necropsy when the animals were about 13 months of age. RESULTS: HFD/HFD juveniles displayed an increased plasma insulin level and glucose-stimulated insulin secretion in comparison with CTR/CTR. In abdominal aorta, but not the renal artery, acetylcholine-induced vasorelaxation was decreased remarkably for HFD/HFD juveniles compared with CTR/CTR. HFD/HFD animals also showed a thicker intima wall and an abnormal vascular-morphology, concurrent with elevated expression levels of several markers related to vascular inflammation and fibrinolytic function. Diet-switching animals (HFD/CTR and CTR/HFD) displayed modest damage on the abdominal vessel. CONCLUSION: Our data indicate that maternal HFD exposure impairs offspring's endothelial function. Both early programming events and postweaning diet contribute to the abnormalities that could be reversed partially by diet intervention.

Plasticity of neuroblastoma tumor cells to differentiate along a fetal adrenal ganglionic lineage predicts for improved patient survival.

We have recently presented a model of human adrenal medullary histogenesis that incorporates all neural crest-derived lineages (chromaffin, sustentacular, and ganglionic) known to compose this tissue. To determine if neuroblastomas correspond to the arrested maturation of embryonal adrenal medullary cells, we evaluated the expression of adrenal medullary developmental markers in 81 neuroblastoma tumors. We found that patterns of chromaffin-related gene expression in these tumors correlated exactly with the patterns observed during maturation of adrenal medullary cells (P2 < 10(-5). In a multivariate Cox proportional hazards analysis of developmental marker expression and other well-recognized prognostic variables, evidence of maturation along a fetal ganglionic lineage, as monitored by HNK-1 immunoreactivity (relative risk of 6.42, P2 = 0.0001), and age at diagnosis (relative risk of 5.05, P2 = 0.0042) were independent and significant prognostic indicators of patient survival. These studies demonstrate that neuroblastomas correspond to embryonal adrenal medullary cells arrested at recognizable stages during development, and that evidence of maturation along a fetal ganglionic lineage appears to have major importance in predicting patient survival.

Insulin-like growth factor II-mediated proliferation of human neuroblastoma.

Neuroblastoma is an embryonal tumor that typically arises in cells of the developing adrenal medulla. IGF-II mRNA is expressed at high levels in the adrenal cortex before birth but it is not detectable until after birth in the adrenal medulla. Neuroblastoma cell lines corresponding to early adrenal medullary precursors did not express IGF-II, although all three cell lines we tested were growth stimulated by IGF-II. Cell lines corresponding to more mature adrenal medullary cells expressed IGF-II, and one, SK-N-AS, grows by an IGF-II autocrine mechanism (J. Clin. Invest. 84:829-839) El-Badry, Romanus, Helman, Cooper, Rechler, and Israel. 1989. An examination of human neuroblastoma tumor tissues for IGF-II gene expression using in situ hybridization histochemistry revealed that IGF-II is expressed by tumor cells in only 5 of 21 neuroblastomas, but is detectable in cells of nonmalignant tissues including adrenal cortical cells, stromal fibroblasts, and eosinophils in all 21 tumors. These findings indicate that IGF-II may function as an autocrine growth factor for some neuroblastomas and as a paracrine growth factor for others. They suggest that the growth regulatory pathways utilized by neuroblastoma mimic those used in the precursor cell type from which individual tumors arise.

Source of increased ferritin in neuroblastoma: studies with concanavalin A-sepharose binding.

Serum ferritin is present in two forms--a glycosylated form that results from active secretion by cells and a nonglycosylated form that is directly released by damaged cells. Glycosylated ferritin binds to concanavalin A (Con A) through the glucose and/or mannose residues of the molecule. Patients with neuroblastoma frequently present at diagnosis with abnormally elevated levels of serum ferritin. The ferritin levels will, however, return to normal with clinical remission, suggesting that the tumor is the origin of the elevated ferritin. With the use of a Con A binding assay, an investigation was made as to whether the increased levels of serum ferritin at diagnosis in neuroblastoma patients resulted from active secretion by the tumor or were the consequence of direct release of ferritin from damaged tissue. Serum samples were collected at diagnosis from 36 children with neuroblastoma and from 16 normal healthy subjects. Tissue ferritins were purified from normal human liver, placenta, HeLa cells, human neuroblastoma, and hepatoma cells grown in culture. Serum and tissue ferritins were measured before and after binding with Con A. Sixty-three percent of serum ferritin from neuroblastoma patients and 66% of serum ferritin from normal subjects were bound to Con A, suggesting that they were glycosylated and were likely to have been secreted. On the other hand, only 28% of tissue ferritin were bound to Con A. Furthermore, most patients showed abnormally elevated levels of serum ferritin, and 63% of these ferritins were bound to Con A. These results are compatible with the hypothesis that much of the elevated ferritin in sera of patients with neuroblastoma seen at diagnosis is the result of secretion of ferritin by the tumor.

Incidence of childhood cancer: experience of a decade in a population-based registry.

Incidence rates of cancer among children aged 0-14 for the period 1970-79 have been generated with the use of data from the Greater Delaware Valley (GDV) Pediatric Tumor Registry. This population-based registry covers a 31-county area and has a pediatric base population of 2 million. During the period, approximately 2,300 cases of childhood cancer were diagnosed in the region. Incidence rates for all histologic types combined are similar to rates from other large surveys conducted in the United States and Western Europe. However, certain histology-specific rates in the GDV vary by race. In the GDV nonwhites relative to whites have higher rates of Wilms' tumor, soft tissue sarcomas other than rhabdomyosarcoma, and retinoblastoma. These contrasts are supported by surveys in African populations showing relatively higher rates of these tumors among African black children. GDV whites exceed nonwhites in incidence of acute leukemia, neuroblastoma, and Ewing's sarcoma. African black children also experience low rates of these tumors. The frequency of central nervous system tumors is similar for GDV whites and nonwhites, despite reports of a rarity of these neoplasms in African blacks. Variations in incidence rates reveal population subgroups with particular tumor susceptibilities and may provide clues as to the relative influence of heredity and environment on patterns observed.

Studies of parents of children with acute leukemia.

In a case-control study, 70 mothers and 24 fathers of children with acute leukemia (AL) were compared with 70 mothers and 24 fathers of normal children. Three significant differences (p smaller than 0.05) were found when 35 factors were compared among the mother pairs and one difference among the father pairs. Mothers of children with AL, though alike in most respects to their matched controls, had a significantly lower number of monocytes than their controls. This was a new observation. The mothers of the children with AL also had higher levels of gamma-globulin, IgA, and IgG (Philadelphia only), which confirmed previous observations. The fathers and mothers had higher levels of basophils. These findings direct attention to the immune systems, particularly the mononuclear cells, of the parents of children with AL, as a focus for further studies on the etiology and pathogenesis of childhood leukemia.

Lack of influence of T-cell marker and importance of mediastinal mass on the prognosis of acute lymphocytic leukemias of childhood.

One hundred consecutive new cases of acute lymphocytic leukemia (ALL) were studied in patients that were 4 months to 16 years of age when admitted to The Children's Hospital of Philadelphia. Various prognostic factors were examined and related to the duration of the first remission. These factors included lymphoblast surface markers, age at diagnosis, sex, race, initial white blood counts (WBC), presence of mediastinal mass, degree of hepatosplenomegaly, and lymph node size. Classification by lymphoblast surface markers showed 22 T-cell, 71 null cell, and 3 B-cell leukemias; 3 cases were unclassifiable and 1 had both T- and B-cell markers. Statistical analysis indicated that stratification by presence or absence of mediastinal mass was necessary. Most patients with mediastinal masses, 5 of thymus and 4 of the non-thymus type, fared poorly with a median duration of continuous complete remission of less than 12 months as compared with greater than 48 months for those without such masses. The most satisfactory model to estimate remission duration in children without mediastinal masses was dependent upon initial WBC, sex, race, and surface markers. Low WBC, white race, female sex, and T-cell markers in patients without mediastinal masses were associated with a favorable prognosis. The findings suggest that patients with mediastinal masses need special therapy and that T-cell ALL without a mediastinal masses need special therapy and that T-cell ALL without a mediastinal mass does not carry a poorer prognosis than does null cell ALL.

Serum ferritin as a guide to therapy in neuroblastoma.

Elevated serum ferritin levels without a corresponding increase in tissue iron storage have been observed in patients with certain cancers. Increased synthesis of ferritin by cancer cells has also been reported. In order to see whether similar phenomena occurred in patients with neuroblastoma, we have screened serum ferritin levels in 58 children with neuroblastoma by counterelectrophoresis using antibody to human ferritin. Increased ferritin levels in serum, positive by counterelectrophoresis (greater than or equal to 400 ng/ml), correlated well with the presence of active disease (p less than 0.001 by Fisher's exact 2 X 2 test). A longitudinal study of serum ferritin levels in 34 of the 58 patients showed the same association of elevated serum ferritin with active disease; a return of ferritin levels to the normal ranges coincided with remission. Primary neuroblastoma tumors and cells from neuroblastoma cell lines contained ferritins with the electrophoretic characteristics different from normal liver ferritin. Supernatant fluids from six neuroblastoma cell lines grown in culture also contained ferritin. These findings suggest that the increased ferritin in the serum of patients is derived from the tumor. The serum ferritin level could be used as indicator of disease activity and as a guide to therapy.

Models to predict outcome from childhood neuroblastoma: the role of serum ferritin and tumor histology.

We report on the development of three multiple logistic regression models to predict death from childhood neuroblastoma in patients treated without bone marrow transplantation. The models have been developed using a data set of 125 patients for whom age, stage, serum ferritin, and/or histology were available from diagnosis. Seventy-seven patients had all four variables recorded at diagnosis, 34 had age, stage, and serum ferritin, and 14 had age, stage, and histology. Minimum time from diagnosis for all patients was 3 years. The four-variable (full) model showed a predictive value positive rate (or 1 - the false positive rate) of 91.3% and a predictive value negative rate (or 1 - the false negative rate) of 94.4%. Survival curves, based on derived "good" and "poor" prognosis, were constructed for the full model of 77 patients and for the same patients using subset models either without ferritin or without histology. Correcting for prognostic factors noted at diagnosis, no time trend could be identified over the study period. Point estimates for the probability of death in all three models are displayed in graphical form. The results suggest that serum ferritin and tumor histology at diagnosis have independent prognostic significance and that patient outcome in neuroblastoma can be very accurately predicted with a four-variable model. Such information will help sort patients into good and poor prognosis for bone marrow transplant and intensive chemotherapy protocol triage and will help evaluate the efficacy of future therapeutic innovations.

Prognostic importance of serum ferritin in patients with Stages III and IV neuroblastoma: the Childrens Cancer Study Group experience.

Ferritin was measured in sera obtained at diagnosis from 241 patients with neuroblastoma to determine (a) the incidence of elevated ferritin and (b) the relationship between ferritin level and outcome. Ferritin was infrequently elevated in sera from patients with Stages I and II disease but was abnormally elevated in 37 and 54% of those with Stages III and IV neuroblastoma, respectively. The mean and median levels for each stage were compared and were highest for Stages III and IV disease. Analysis of progression-free survival for children with Stages III and IV disease indicated that elevated ferritin was associated with a significantly poorer prognosis than was normal ferritin and that this correlation was independent of stage and age at diagnosis. Progression-free survival at 24 months of follow-up for patients with Stage III disease with normal ferritin was 76% and with elevated ferritin was 23%. For those with Stage IV disease, progression-free survival was 27 and 3% with normal and elevated ferritin, respectively. We conclude that determination of the level of ferritin in serum at diagnosis is useful for selecting appropriate therapy for patients with Stage III neuroblastoma. Those with normal ferritin (63% of patients) have a good outcome with current therapy, but those with elevated ferritin (37%) do poorly and require more effective therapy. Although ferritin defines subgroups with Stage IV disease, the outcome of all groups must be improved.

Analysis of nerve growth factor receptor expression in human neuroblastoma and neuroepithelioma cell lines.

A series of 22 neuroepithelioma and neuroblastoma cell lines were screened for expression of nerve growth factor receptor (NGFR) by flow cytometry, Western blotting, and Northern blotting. All 5 neuroepithelioma cell lines expressed cell surface NGFR, with 30-69% of cells NGFR positive, but the 17 neuroblastoma cell lines tested had a smaller percentage of cell surface NGFR-positive cells (0-21%) and 10 lines were completely lacking cell surface NGFR. SY5Y, a variant line with a neuronal phenotype derived from neuroblastoma line SKNSH, expressed much more NGFR than SHEP, a variant line with an epithelial-like phenotype also derived from SKNSH. By Western blotting, the Mr approximately 69,000 NGFR band was detected for all four neuroepithelioma cell lines tested but was visible for only 8 of 15 neuroblastoma cell lines tested. The band was most intense for neuroepithelioma cell lines SKNMC and TC32. For these two lines, a Mr approximately 56,000 and a Mr approximately 60,000 band were also detected. By Northern blotting, all three neuroepithelioma cell lines tested were positive for the 3.8 kilobase NGFR mRNA, but only 8 of 15 neuroblastoma cell lines were positive. Neuroepithelioma cell line TC32 and neuroblastoma cell line GICAN had the strongest expression of NGFR mRNA. These results demonstrate that NGFR is a biological marker for neuroepithelioma and that NGFR expression is heterogeneous for neuroblastoma cell lines. This series of neural cell lines differing in NGFR expression will be useful for future studies of regulation of NGFR expression and neuronal differentiation.

The human non-muscle alpha-actinin protein encoded by the ACTN4 gene suppresses tumorigenicity of human neuroblastoma cells.

alpha-Actinins are actin-binding proteins important in organization of the cytoskeleton and in cell adhesion. We have cloned and characterized a cDNA from human neuroblastoma cell variants which encodes the second non-muscle alpha-actinin isoform designated ACTN4 (actinin-4). mRNA encoded by the ACTN4 gene, mapped to chromosome 4, is abundant in non-tumorigenic, substrate-adherent human neuroblastoma cell variants but absent or only weakly expressed in malignant, poorly substrate-adherent neuroblasts. It is also present in many adherent tumor cell lines of diverse tissue origins. Cell lines typically co-express ACTN4 and ACTN1, a second non-muscle alpha-actinin gene. Expression is correlated with substrate adhesivity. Analysis of deduced amino acid sequences suggests that the two isoforms may differ in function and in regulation by calcium. Moreover, ACTN4 exhibits tumor suppressor activity. Stable clones containing increased levels of alpha-actinin, isolated from highly malignant neuroblastoma stem cells [BE(2)-C] after transfection with a full-length ACTN4 cDNA, show decreased anchorage-independent growth ability, loss of tumorigenicity in nude mice, and decreased expression of the N-myc proto-oncogene.

Successful management of low-stage neuroblastoma without adjuvant therapies: a comparison of two decades, 1972 through 1981 and 1982 through 1992, in a single institution.

PURPOSE: A review was undertaken of 119 children seen at the Children's Hospital of Philadelphia between 1972 and 1992 to assess the impact of adjuvant therapies for patients with low-stage neuroblastoma (NBL). PATIENTS AND METHODS: Twenty-one of 119 International Neuroblastoma Staging System (INSS) stage 1, 2a, 2b, and 4s patients seen received initial adjuvant treatment postoperatively and 98 did not. The patients were further subdivided according to decade, age, presence of residual disease, and lymph node status. Outcomes were then compared. RESULTS: The event-free survival (EFS) rate for those who received adjuvant therapy was 52% versus 86% for those who did not. The 5-year survival rate was 68% and 94%, respectively. Age (< or > 12 months), extent of residual disease, and status of lymph nodes did not influence survival. Over the two decades, the reasons for selecting treatment changed as new and powerful additional prognostic factors were identified; 71% of patients received no adjuvant treatment in the first decade, compared with 90% in the second. EFS rates for untreated patients by decade were 79% and 89%, and 5-year survival rates were 85% and 98%, respectively. CONCLUSION: It is possible to define most low-stage NBL as favorable-even in patients with positive lymph nodes and gross residual disease-and to omit initial adjuvant treatments successfully.

Expression of the neurotrophin receptor TrkB is associated with unfavorable outcome in Wilms' tumor.

PURPOSE: Neurotrophins and their receptors regulate the proliferation, differentiation, and death of neuronal cells, and they have been implicated in the pathogenesis and prognosis of neuroblastomas and medulloblastomas. Tyrosine kinase (Trk) receptors also are expressed in extraneural tissues. PATIENTS AND METHODS: To study the role of neurotrophin receptors and ligands in Wilms' tumor (WT), we determined their expression by semiquantitative duplex reverse transcriptase polymerase chain reaction in 39 patients with primary WT. Comparison of mRNA expression levels with clinical variables was performed by use of Cox regression analysis. RESULTS: Children with WT that expressed high levels of full-length TrkB mRNA (TrkBfull) had a significantly greater risk of death than children whose tumors had little or no TrkBfull expression (hazard ratio, 9.7; P =.02). The 5-year relapse-free survival was 100% versus 65% for patients with low versus high tumor expression of TrkBfull (P <.003). Conversely, children with tumors that expressed high mRNA levels of a functionally inactive truncated TrkB receptor (TrkBtrunc) had a greater chance of survival than children with low levels of TrkBtrunc (hazard ratio, 0.08; P =.005). The 5-year relapse-free survival was 95% versus 68% for patients with high versus low levels of TrkBtrunc (P =.01). The hazard ratios for TrkBfull and TrkBtrunc remained significant after they were adjusted for tumor stage (P =.01 and P =.017, respectively). All WTs with high levels of TrkB expression also expressed the brain-derived nerve growth factor ligand. CONCLUSION: Expression of TrkBfull in WT is associated with worse outcome, perhaps because it provides an autocrine survival pathway. Conversely, TrkBtrunc expression is associated with excellent outcome, perhaps as a result of a dominant negative effect.

International criteria for diagnosis, staging, and response to treatment in patients with neuroblastoma.

Neuroblastoma is one of the most common tumors in childhood. However, it often has been difficult to compare clinical and laboratory studies of this disease due to a lack of uniform criteria for diagnosis, staging, and response. An international group of conferees addressed each of these issues and reached a consensus. Specific criteria for making a diagnosis of neuroblastoma are defined. A new neuroblastoma staging system is proposed that takes into account the most important elements of current but incompatible systems. Finally, criteria for response to treatment are standardized. The criteria proposed herein represent an international consensus of essentially every major pediatric oncology group or organization in the United States, Europe, and Japan. The staging system should be referred to as the International Neuroblastoma Staging System, and the response criteria as the International Neuroblastoma Response Criteria. Implementation of these criteria will greatly facilitate the comparison of clinical and laboratory studies by different groups and countries. Furthermore, these criteria should serve as a foundation on which future modifications or improvements can be based.

Revisions of the international criteria for neuroblastoma diagnosis, staging, and response to treatment.

PURPOSE AND METHODS: Based on preliminary experience, there was a need for modifications and clarifications in the International Neuroblastoma Staging System (INSS) and International Neuroblastoma Response Criteria (INRC). In 1988, a proposal was made to establish an internationally accepted staging system for neuroblastoma, as well as consistent criteria for confirming the diagnosis and determining response to therapy (Brodeur GM, et al: J Clin Oncol 6:1874-1881, 1988). A meeting was held to review experience with the INSS and INRC and to revise or clarify the language and intent of the originally proposed criteria. Substantial changes included a redefinition of the midline, restrictions on age and bone marrow involvement for stage 4S, and the recommendation that meta-iodobenzylguanidine (MIBG) scanning be implemented for evaluating the extent of disease. Other modifications and clarifications of the INSS and INRC are presented. In addition, the criteria for the diagnosis of neuroblastoma were modified. Finally, proposals were made for the development of risk groups that incorporate both clinical and biologic features in the prediction of prognosis. The biologic features that were deemed important to evaluate prospectively included serum ferritin, neuron-specific enolase (NSE), and lactic dehydrogenase (LDH); tumor histology; tumor-cell DNA content; assessment of N-myc copy number; assessment of 1p deletion by cytogenetic or molecular methods; and TRK-A expression. RESULTS AND CONCLUSION: Modifications of the INSS and INRC made at this conference are presented. In addition, proposals are made for future modifications in these criteria and for the development of International Neuroblastoma Risk Groups.

A comparison of four staging systems for localized and regional neuroblastoma: a report from the Childrens Cancer Study Group.

Four major staging systems have been used to estimate the prognosis for children with local and regional neuroblastoma (NBL). Data obtained at diagnosis for 251 neuroblastoma patients from two Childrens Cancer Study Group (CCSG) studies were analyzed according to staging systems of the CCSG, St Jude Children's Research Hospital, the Pediatric Oncology Group (POG), and the Union Internationale Contre le Cancer (UICC) tumor-nodes-metastasis (TNM) system. The most significant variables were found to be age, tumor stage, extent of tumor removal, transgression of the midline by tumor infiltration, and site of primary tumor. Involvement of lymph nodes per se was not a bad prognostic sign unless associated with extension beyond the midline, the latter being the single most important prognostic variable. All four staging systems had value for prognostication and all identified with accuracy the low stage patient (stage I, stage A) who fares well (greater than or equal to 87% survival). The CCSG definition of stages II and III disease discriminated prognostic groups best among the remaining patients, and was able to identify the child with local-regional NBL with poor survival. The estimated 5-year survival rates for children with regional tumor (stage III, IIIA[N]), according to the four systems were 44%, 74%, 74%, and 74% for the CCSG, St Jude, POG, and UICC methods, respectively. We conclude that all four staging systems effectively define good-prognosis patients with localized disease but that the CCSG staging system most accurately identifies patients with regional tumor who have a poor outcome.

Treatment of advanced neuroblastoma with supralethal chemotherapy, radiation, and allogeneic or autologous marrow reconstitution.

Ten children with recurrent metastatic (stage IV) neuroblastoma received local radiation therapy, supralethal chemotherapy, and total-body irradiation. Rescue with infusions of either allogeneic (four patients) or autologous (six patients) bone marrow followed. The drugs given to the first two patients were individualized combinations based on previous tumor responses. Both patients died with recurrent tumor three and nine months posttransplant. The eight remaining patients were treated more uniformly with local irradiation, VM-26, doxorubicin, melphalan (L-phenylalanine mustard), and 1,000-rad total-body irradiation in three fractions. Two of these patients had cardiac dysfunction and received no doxorubicin. Three children died in the immediate posttransplant period with disseminated fungal infections. A fourth relapsed and died nine months posttransplant. As of December 1, 1983, two children who received allogeneic marrow grafts have survived in complete remission for 54 and 36 months, and two children who received autologous marrow grafts have survived in complete remission for 35 and 22 months. These results suggest that relapsed metastatic neuroblastoma can be controlled by supralethal combinations of chemotherapy and irradiation coupled with bone-marrow rescue.

Hypoxia-regulated glucose transporter Glut-1 may influence chemosensitivity to some alkylating agents: results of EORTC (First Translational Award) study of the relevance of tumour hypoxia to the outcome of chemotherapy in human tumour-derived xenografts.

Tumour hypoxia confers poor prognosis in a wide range of solid tumours, due to an increased malignancy, increased likelihood of metastasis and treatment resistance. Poorly oxygenated tumours are resistant to both radiation therapy and chemotherapy. However, although the link between radiation therapy and hypoxia is well established in a range of clinical studies, evidence of its influence on chemotherapy response is lacking. In this study, a panel of human tumour-derived xenografts that have been characterised previously for in vivo response to a large series of anti-cancer agents, and have been found to show chemosensitivities that correlate strongly with the parent tumour, were used to address this issue. Immunohistochemistry was carried out on formalin-fixed, paraffin-embedded sections of xenograft samples to detect expression of the intrinsic hypoxia marker Glut-1 and adducts of the bioreductive hypoxia marker pimonidazole. Glut-1 scores correlated significantly with T/C values for CCNU sensitivity (r = 0.439, P = 0.036, n = 23) and showed a borderline significant correlation with dacarbazine T/C (r = 0.405, P = 0.076, n = 20). However, there was no correlation between both Glut-1 and pimonidazole scores and T/C obtained for the bioreductive drug mitomycin C. The use of human tumour-derived xenografts offers a potentially useful way of using archival material to determine the influence of hypoxia and other tumour-microenvironmental factors on chemosensitivity without the direct use of human subjects.