The postulated innocuity of lifetime exposure to aluminium should be reappraised.

Because of its chemical versatility and abundance in nature, aluminium is employed in a myriad of frequently used products - including cosmetics and food additives - and applications - drinking water purification procedures being an example. Despite what its widespread use might suggest, aluminium's harmlessness is a matter of debate in the scientific community. In this article we trace the lines of a growing questioning about the potential mutagenic effects of this metal, due to the data produced over the recent years, and with an eye to the discussions currently underway in this regard between the scientific community, industry, and regulatory bodies.

Aluminum Enters Mammalian Cells and Destabilizes Chromosome Structure and Number.

Chromosome instability (CIN) consists of high rates of structural and numerical chromosome abnormalities and is a well-known hallmark of cancer. Aluminum is added to many industrial products of frequent use. Yet, it has no known physiological role and is a suspected human carcinogen. Here, we show that V79 cells, a well-established model for the evaluation of candidate chemical carcinogens in regulatory toxicology, when cultured in presence of aluminum-in the form of aluminum chloride (AlCl3) and at concentrations in the range of those measured in human tissues-incorporate the metal in a dose-dependent manner, predominantly accumulating it in the perinuclear region. Intracellular aluminum accumulation rapidly leads to a dose-dependent increase in DNA double strand breaks (DSB), in chromosome numerical abnormalities (aneuploidy) and to proliferation arrest in the G2/M phase of the cell cycle. During mitosis, V79 cells exposed to aluminum assemble abnormal multipolar mitotic spindles and appear to cluster supernumerary centrosomes, possibly explaining why they accumulate chromosome segregation errors and damage. We postulate that chronic aluminum absorption favors CIN in mammalian cells, thus promoting carcinogenesis.

Genomic Instability Is an Early Event in Aluminium-Induced Tumorigenesis.

Genomic instability is generally considered as a hallmark of tumorigenesis and a prerequisite condition for malignant transformation. Aluminium salts are suspected environmental carcinogens that transform mammary epithelial cells in vitro through unknown mechanisms. We report here that long-term culture in the presence of aluminium chloride (AlCl3) enables HC11 normal mouse mammary epithelial cells to form tumours and metastases when injected into the syngeneic and immunocompetent BALB/cByJ strain. We demonstrate that AlCl3 rapidly increases chromosomal structural abnormalities in mammary epithelial cells, while we failed to detect direct modulation of specific mRNA pathways. Our observations provide evidence that clastogenic activity-a well-recognized inducer of genomic instability-might account in part for the transforming abilities of aluminium in mammary epithelial cells.

Aluminium chloride promotes tumorigenesis and metastasis in normal murine mammary gland epithelial cells.

Aluminium salts, present in many industrial products of frequent use like antiperspirants, anti-acid drugs, food additives and vaccines, have been incriminated in contributing to the rise in breast cancer incidence in Western societies. However, current experimental evidence supporting this hypothesis is limited. For example, no experimental evidence that aluminium promotes tumorigenesis in cultured mammary epithelial cells exists. We report here that long-term exposure to concentrations of aluminium-in the form of aluminium chloride (AlCl3 )-in the range of those measured in the human breast, transform normal murine mammary gland (NMuMG) epithelial cells in vitro as revealed by the soft agar assay. Subcutaneous injections into three different mouse strains with decreasing immunodeficiency, namely, NOD SCID gamma (NSG), NOD SCID or nude mice, revealed that untreated NMuMG cells form tumors and metastasize, to a limited extent, in the highly immunodeficient and natural killer (NK) cell deficient NSG strain, but not in the less permissive and NK cell competent NOD SCID or nude strains. In contrast, NMuMG cells transformed in vitro by AlCl3 form large tumors and metastasize in all three mouse models. These effects correlate with a mutagenic activity of AlCl3 . Our findings demonstrate for the first time that concentrations of aluminium in the range of those measured in the human breast fully transform cultured mammary epithelial cells, thus enabling them to form tumors and metastasize in well-established mouse cancer models. Our observations provide experimental evidence that aluminium salts could be environmental breast carcinogens.

If exposure to aluminium in antiperspirants presents health risks, its content should be reduced.

Since aluminium (Al) pervades our environment, the scientific community has for many years raised concerns regarding its safety in humans. Al is present in numerous cosmetics such as antiperspirants, lipsticks and sunscreens. Al chlorohydrate is the active antiperspirant agent in underarm cosmetics and may constitute for Al a key exposure route to the human body and a potential source of damage. An in vitro study has demonstrated that Al from antiperspirant can be absorbed through viable human stripped skin. The potential toxicity of Al has been clearly shown and recent works convincingly argue that Al could be involved in cancerogenic processes. Nowadays, for example, Al is suspected of being involved in breast cancer. Recent work in cells in culture has lent credence to the hypothesis that this metal could accumulate in the mammary gland and selectively interfere with the biological properties of breast epithelial cells, thereby promoting a cascade of alterations reminiscent of the early phases of malignant transformation. In addition, several studies suggest that the presence of Al in human breast could influence metastatic process. As a consequence, given that the toxicity of Al has been widely recognized and that it is not a physiological component in human tissues, reducing the concentration of this metal in antiperspirants is a matter of urgency.

Aluminium chloride promotes anchorage-independent growth in human mammary epithelial cells.

Aluminium salts used as antiperspirants have been incriminated as contributing to breast cancer incidence in Western societies. To date, very little or no epidemiological or experimental data confirm or infirm this hypothesis. We report here that in MCF-10A human mammary epithelial cells, a well-established normal human mammary epithelial cell model, long-term exposure to aluminium chloride (AlCl(3) ) concentrations of 10-300 µ m, i.e. up to 100 000-fold lower than those found in antiperspirants, and in the range of those recently measured in the human breast, results in loss of contact inhibition and anchorage-independent growth. These effects were preceded by an increase of DNA synthesis, DNA double strand breaks (DSBs), and senescence in proliferating cultures. AlCl(3) also induced DSBs and senescence in proliferating primary human mammary epithelial cells. In contrast, it had no similar effects on human keratinocytes or fibroblasts, and was not detectably mutagenic in bacteria. MCF-10A cells morphologically transformed by long-term exposure to AlCl(3) display strong upregulation of the p53/p21(Waf1) pathway, a key mediator of growth arrest and senescence. These results suggest that aluminium is not generically mutagenic, but similar to an activated oncogene, it induces proliferation stress, DSBs and senescence in normal mammary epithelial cells; and that long-term exposure to AlCl(3) generates and selects for cells able to bypass p53/p21(Waf1) -mediated cellular senescence. Our observations do not formally identify aluminium as a breast carcinogen, but challenge the safety ascribed to its widespread use in underarm cosmetics.

GSTP1 hypermethylation is associated with reduced protein expression, aggressive disease and prognosis in neuroblastoma.

Epigenetic modifications such as methylation of CpG islands in tumor-suppressor gene promoter regions have been associated with tumor development in many human cancers. Using methylation specific multiplex ligation-dependent probe amplification method, we analyzed the methylation status of 35 different genes in 16 neuroblastoma (NB) cell lines and 50 NB tumor samples (NBs), and investigated whether specific hypermethylation was associated with biological and/or clinical parameters. Among the genes found hypermethylated, the effect of GSTP1 hypermethylation on mRNA and protein expression was also explored. The median number of hypermethylated genes was higher in cell lines compared to NBs (5.5 vs. 2). For eight genes, aberrant methylation of CpG-islands in NB was not (ESR1, PAX5, WT1, CADM1, MSH6, and CDKN2B) or very rarely (CDH13 and GSTP1) reported in literature. GSTP1 was found hypermethylated in 44% of the NB cell lines and in 33% of the stage 4-11qLOH -non MYCN-amplified high risk NBs. Hypermethylation was correlated with reduced mRNA and protein expression. In the whole NBs cohort, GSTP1 hypermethylation was less frequently detected (8%), but found to be associated with lower event-free (EFS) and overall survival. Hypermethylation of GSTP1 showed also association with lower EFS in high risk subgroups as stage 4 and older patients (≥547 days). Our results suggest that, as in several adult cancers, aberrant methylation of GSTP1 may contribute to the carcinogenetic process in NB and could be potentially used as a new marker leading to define an ultra-high risk subgroup.

Ataxia telangiectasia mutated (ATM) inhibition transforms human mammary gland epithelial cells.

Carriers of mutations in the cell cycle checkpoint protein kinase ataxia telangiectasia mutated (ATM), which represent 1-2% of the general population, have an increased risk of breast cancer. However, experimental evidence that ATM deficiency contributes to human breast carcinogenesis is lacking. We report here that in MCF-10A and MCF-12A cells, which are well established normal human mammary gland epithelial cell models, partial or almost complete stable ATM silencing or pharmacological inhibition resulted in cellular transformation, genomic instability, and formation of dysplastic lesions in NOD/SCID mice. These effects did not require the activity of exogenous DNA-damaging agents and were preceded by an unsuspected and striking increase in cell proliferation also observed in primary human mammary gland epithelial cells. Increased proliferation correlated with a dramatic, transient, and proteasome-dependent reduction of p21(WAF1/CIP1) and p27(KIP1) protein levels, whereas little or no effect was observed on p21(WAF1/CIP1) or p27(KIP1) mRNAs. p21(WAF1/CIP1) silencing also increased MCF-10A cell proliferation, thus identifying p21(WAF1/CIP1) down-regulation as a mediator of the proliferative effect of ATM inhibition. Our findings provide the first experimental evidence that ATM is a human breast tumor suppressor. In addition, they mirror the sensitivity of ATM tumor suppressor function and unveil a new mechanism by which ATM might prevent human breast tumorigenesis, namely a direct inhibitory effect on the basal proliferation of normal mammary epithelial cells.

Prevalence of burnout among Swiss cancer clinicians, paediatricians and general practitioners: who are most at risk?

GOALS OF WORK: Increasing economical and administrative constraints and changes in health-care systems constitute a risk for burnout, especially for cancer physicians. However, little is known about differences across medical specialties and the importance of work characteristics. METHODS: A postal questionnaire addressing burnout, psychiatric morbidity, sociodemographics and work characteristics was administered to 180 cancer physicians, 184 paediatricians and 197 general practitioners in Switzerland. RESULTS: A total of 371 (66%) physicians participated in the survey. Overall, one third of the respondents expressed signs indicative of psychiatric morbidity and of burnout, including high levels of emotional exhaustion (33%) and depersonalisation/cynicism (28%) and a reduced feeling of personal accomplishment (20%). Workload (>50 h/week), lack of continuing education (<6 h/month) and working in a public institution were significantly associated with an increased risk of burnout. After adjustment for these characteristics, general practitioners had a higher risk for emotional exhaustion (OR: 2.0, 95% CI: 1.1 to 3.6) and depersonalisation (OR: 2.7, 95% CI: 1.4 to 5.3). CONCLUSION: In this Swiss sample, cancer clinicians had a significant lower risk of burnout, despite a more important workload. Among possible explanations, involvement in research and teaching activities and access to continuing education may have protected them.

Detection of ATM gene deletion/duplication by multiplex ligation-dependant probe amplification in childhood lymphoid malignancies: a report from the Children's Oncology Group.

ATM gene alterations have been described in various lymphoproliferative malignancies suggesting that ATM contributes to lymphomagenesis. Using multiplex ligation-dependant probe amplification (MLPA), we screened 61 childhood lymphoid malignancies for ATM genomic deletion/duplication. Five samples were found to have a complete deletion or duplication. All the three deletions were found in B-precursor ALL (15%), two were submicroscopic, not detected by standard cytogenetic studies. These observations indicate that as in adult ALL, complete ATM submicroscopic deletion is frequent in childhood B-precursor ALL. As previously hypothesized, these results suggest that ATM may act as a tumor suppressor gene in the pathogenesis of childhood B-precursor ALL.

Percutaneous cementoplasty in multiple myeloma: a valuable adjunct for pain control and ambulation maintenance.

GOALS OF WORK: Bone pain and functional impairment are major concerns for multiple myeloma (MM) patients. The goal of this study was to better define the role of percutaneous cementoplasty (PC) in improving their quality of life. MATERIALS AND METHODS: This retrospective analysis included 28 consecutive heavily pretreated MM patients managed at our institution between 1996 and 2002. They underwent a total of 34 PC procedures for the treatment of 117 vertebrae and 2 iliac sites and were evaluated at 1 month. MAIN RESULTS: Significant pain reduction of >50% was obtained after 83% of the procedures, with a mean visual analogous score decreasing from 7.48/10 to 2.1/10 (p < 0.001). It resulted in a complete interruption of opiate analgesic consumption after 59.3% of the procedures, with a mean decrease of 70.4% in the opiate dose. Functional impairment was evaluated with the Eastern Cooperative Oncology Group (ECOG) performance status scale, with mean scores improving from 1.9 to 0.86 after the procedures (p = 0.001). There was no major complication. CONCLUSION: PC is a safe, feasible, and efficient approach for the treatment of bone pain and disability in MM patients.

Tumor location of the lower-inner quadrant is associated with an impaired survival for women with early-stage breast cancer.

BACKGROUND: There is growing evidence that tumors of the inner quadrants (especially the lower-inner quadrant) metastasize more often to the internal mammary chain (IMC). As these metastases are not investigated, patients with lower-inner quadrant tumors have an increased risk of being under-staged and under-treated and may therefore have a higher risk of death from breast cancer. METHODS: We identified all 1522 women operated for stage I breast cancer between 1984 and 2002 recorded at the population-based Geneva Cancer Registry. We compared breast cancer mortality risk by tumor location with multivariate Cox regression analysis that accounted for all factors linked to tumor location and survival. RESULTS: Ten-year disease-specific survival was 93% (95%CI: 91-94%). Patients with breast cancer of the lower-inner quadrant (n = 118; 7.8%) had an importantly increased risk of dying of breast cancer compared to women with breast cancer of the upper-outer quadrant (multiadjusted Hazard Ratio: 2.3, 95%CI: 1.1-4.5, P = 0.0206). The over-mortality associated with this quadrant was particularly evident for tumors >10 mm (multiadjusted HR: 3.6, 95%CI: 1.6-7.9, P = 0.0016). There was no increased breast cancer mortality risk for tumors located in other quadrants. CONCLUSIONS: Tumor location in the lower-inner quadrant is an independent and important prognostic factor of stage I breast cancer. Further research is needed to evaluate if the over-mortality of patients with stage I cancer of the lower-inner quadrant is indeed a result of under-treatment due to undetected IMC metastases. If so, patients with stage I breast cancer of the lower-inner quadrant are good candidates for systematic IMC investigation.

Survival after bilateral breast cancer: results from a population-based study.

BACKGROUND: Controversy exists on the impact of bilaterality of breast cancer on survival. We used population-based data to compare survival of women with unilateral versus bilateral breast cancer. PATIENTS AND METHODS: At the Geneva cancer registry, we identified all 7,912 women diagnosed with invasive breast cancer between 1970 and 2002. Breast cancers were categorized as unilateral, synchronous bilateral (contralateral tumour diagnosed within six months after the first tumour) and metachronous bilateral (contralateral tumour diagnosed over six months after the first tumour). With multivariate modelling we compared characteristics and survival between women with unilateral and bilateral disease. RESULTS: Patients with synchronous bilateral tumours (n = 155, 2.0%) had more often lobular histology and less frequently stage I disease than women with unilateral disease. Women with metachronous breast cancer (n = 219, 2.8%) received less often chemotherapy or hormone therapy for their first tumours. Ten-year disease-specific survival was similar (66%) after unilateral and metachronous bilateral breast cancer, but worse after synchronous bilateral cancer (51%). After adjustment, breast cancer mortality risks were not significantly increased for women with either synchronous or metachronous bilateral disease (Hazard ratios 1.1 (0.8-1.5) and 0.8 (0.5-1.4), respectively). CONCLUSION: This large population-based study indicates that bilaterality of breast cancer is not associated with impaired survival.

Twenty-three novel BRCA1 and BRCA2 sequence variations identified in a cohort of Swiss breast and ovarian cancer families.

BRCA1 and BRCA2 are the major genes predisposing to breast-ovarian cancer (i.e., breast or ovarian cancer or both). Since 1994, hundreds of distinct germline alterations have been reported in these two genes. Besides pathogenic mutations resulting in loss of function of the protein, an increased number of variants of unknown clinical significance have been described. In a cohort of 350 Swiss breast-ovarian cancer families, the systematic search for BRCA1/BRCA2 germline mutations was carried out using denaturating high-performance liquid chromatography as the first screening procedure. The screening strategy resulted in the identification of 23 alterations not previously reported: 9 in BRCA1 and 14 in BRCA2. By using the available tools to assign a functional role to newly identified sequence variations, 5 (22%) of these were classified as new disease-causing mutations, 5 (22%) were classified as benign polymorphisms, and the remaining 13 (56%) alterations were considered as unclassified variants. These data illustrate the major challenge for clinical oncologists currently facing the interpretation of alterations identified in BRCA1 or BRCA2. The key points are to classify these genetic variations as pathogenic mutations, benign polymorphisms, or variants of unknown clinical significance and to adequately use this information for the management of high-risk individuals and their families.

Complete excision of primary breast tumor improves survival of patients with metastatic breast cancer at diagnosis.

PURPOSE: Surgery of the primary tumor usually is not advised for patients with metastatic breast cancer at diagnosis because the disease is considered incurable. In this population-based study, we evaluate the impact of local surgery on survival of patients with metastatic breast cancer at diagnosis. METHODS: We included all 300 metastatic breast cancer patients recorded at the Geneva Cancer Registry between 1977 and 1996. We compared mortality risks from breast cancer between patients who had surgery of the primary breast tumor to those who had not and adjusted these risks for other prognostic factors. RESULTS: Women who had complete excision of the primary breast tumor with negative surgical margins had a 40% reduced risk of death as a result of breast cancer (multiadjusted hazard ratio [HR], 0.6; 95% CI, 0.4 to 1.0) compared with women who did not have surgery (P = .049). This mortality reduction was not significantly different among patients with different sites of metastasis, but in the stratified analysis the effect was particularly evident for women with bone metastasis only (HR, 0.2; 95% CI, 0.1 to 0.4; P = .001). Survival of women who had surgery with positive surgical margins was not different from that of women who did not have surgery. CONCLUSION: Complete surgical excision of the primary tumor improves survival of patients with metastatic breast cancer at diagnosis, particularly among women with only bone metastases.

ATM alterations in childhood non-Hodgkin lymphoma.

ATM gene alterations and impaired ATM protein expression have been described in various adult lymphoproliferative malignancies, suggesting that ATM contributes to lymphomagenesis. The present study investigated the prevalence of ATM gene and ATM protein expression alterations in sporadic childhood non-Hodgkin lymphoma (NHL). Twenty-seven cases of NHL were screened for ATM mutations by denaturing high-performance liquid chromatography (DHPLC). Direct and indirect criteria, including in silico tools, were used to classify the gene alterations. The methylation status of the ATM promoter CpG island was determined in 25 samples; ATM protein expression was assessed by Western blot in 9 lymphomas. ATM alterations were detected in 12 NHLs (44%). Ten different heterozygous base substitutions were identified in 10 NHLs (37%). Five samples (19%) were found to harbor a gene alteration considered to be a mutation or a rare variant potentially pathogenic. In one case, an ATM mutation was found in the germline. Four NHLs (44%) showed reduced or absent ATM protein expression. Except for one sample, no definite genetic or epigenetic alteration was identified to account for impaired ATM protein expression. These observations document a high prevalence of ATM gene and protein expression alterations, suggesting that ATM is involved in childhood NHL.