The DNA-instability test as a specific marker of malignancy and its application to detect cancer clones in borderline malignancy

Recent progress in cytogenetic and biochemical mutation assay technologies has enabled us to detect single gene alterations and gross chromosomal rearrangements, and it became clear that all cancer cells are genetically unstable. In order to detect the genome-wide instability of cancer cells, a new simple method, the DNA-instability test, was developed. The methods to detect genomic instability so far reported have only demonstrated the presence of qualitative and quantitative alterations in certain specific genomic loci. In contrast to these commonly used methods to reveal the genomic instability at certain specific DNA regions, the newly introduced DNA-instability test revealed the presence of physical DNA-instability in the entire DNA molecule of a cancer cell nucleus as revealed by increased liability to denature upon HCl hydrolysis or formamide exposure. When this test was applied to borderline malignancies, cancer clones were detected in all cases at an early-stage of cancer progression. We proposed a new concept of "procancer" clones to define those cancer clones with "functional atypia" showing positivities for various cancer markers, as well as DNA-instability testing, but showing no remarkable ordinary "morphological atypia" which is commonly used as the basis of histopathological diagnosis of malignancy.

A phase III comparison of prophylactic cranial irradiation versus observation in patients with locally advanced non-small cell lung cancer: Initial analysis of Radiation Therapy Oncology Group 0214

7506

Background: The incidence of central nervous system (CNS) metastases is high in patients with locally advanced non-small cell lung cancer. Brain as an only site of relapse appears increasingly common as loco-regional and extra-cranial systemic treatment improves. There is not standard agreement as to how to address this risk. Methods: Patients with stage III NSCLC without progression of disease after loco-regional treatment with surgery and/or radiation therapy with or without chemotherapy were eligible. Participants were randomized to prophylactic cranial irradiation (PCI) or observation and stratified by stage (IIIA or B), histology (non-squamous or squamous) and therapy (surgery or no surgery). PCI was delivered once daily at 2Gy per fraction to 30Gy. The primary endpoint of the study was overall survival (OS). Secondary endpoints were disease free survival (DFS) and the impact of PCI on incidence of CNS metastases, neuropsychological function, and quality of life (QoL). Kaplan- Meier estimation with the log-rank test was used for OS and DFS and the logistic regression model was used for calculating the incidence of CNS metastasis. Results: Total accrual was 356 patients of the targeted 1058 between 9/19/02 and 8/30/07. The study was closed early due to slow accrual. 340 patients were evaluable. One year OS (p=0.86, 75.6 % and 76.9% for PCI and observation) and one year DFS (p=0.11, 56.4% and 51.2% for PCI and observation) were not statistically significantly different. However, CNS metastatic rate at 1 year was statistically significantly different with CNS relapse 7.7% vs. 18% for PCI vs. observation (p=0.004). Logistic regression showed that the patients in the observation arm are 2.52 times more likely to develop CNS metastases than those in the PCI arm (odds ratio=2.52, 95% CI=(1.32–4.80)). Conclusions: PCI in patients without progressive disease after loco-regional therapy for III NSCLC significantly decreases the rate of CNS metastases. This study did not show a statistically significant difference in OS or DFS. Forthcoming analysis of the impact of PCI on neuropsychological function and QoL will influence the recommendations regarding the standard use of PCI.

No significant financial relationships to disclose.

Impact of positron emission tomography (PET) in stage III non-small cell lung cancer (NSCLC): A prospective randomized trial (PET START)

7548

Background: Patients with stage III NSCLC are potentially curable using combined modality therapy (CMT) with chemotherapy and radical radiation (RT). The use of PET-CT rather than conventional imaging (CI) may better identify patients for CMT by enhanced tumor staging and improved definition of RT treatment volumes. Methods: Patients with stage III NSCLC (based on histology/cytology, brain CT/MRI, CT thorax, CT/US abdomen, and bone scan) who were considered candidates for CMT were randomized to either PET-CT or CT for RT treatment planning. The primary outcome was the proportion of patients who did not receive CMT because their tumor was upstaged to Stage 4 or their intrathoracic tumor was too extensive for radical RT. Overall survival (OS) and alteration of RT treatment planning volume were secondary outcomes. Target sample size was 400 patients based on a hazard rate reduction of 30% in OS at 2 years in favor of PET-CT with 2-sided alpha = 0.05 and 80% power. We also postulated that 200 patients would be required to detect a 20% difference between arms for the primary endpoint. 5 centers in Ontario participated. Results: The trial commenced in August 2004. In November 2008 after a planned interim analysis for the primary outcome, the Data Safety Monitoring Board recommended stopping recruitment because of superior efficacy with PET-CT. 304 patients were randomized and 289 had analyzable data. 25 patients were unsuitable for CMT: 21 in the PET-CT arm (16 upstaged to Stage 4 and 5 unsuitable for radical RT) and 4 in the CT arm (unsuitable for radical RT). Thus, 21 of 140 (15%) patients in the PET-CT arm achieved the primary outcome compared with 4 of 149 (2.7%) in the CT arm, P= 0.0002. Conclusions: This is the first randomized trial in stage III NSCLC showing that PET-CT is superior to CT planning alone in selecting appropriate patients for CMT. Longer patient follow-up will determine potential impact on OS.

No significant financial relationships to disclose.

Development of a breast cancer brain metastases model to study 131I radioablative therapy

Abstract #2011

Background: An increasing number of women develop brain metastases (BM) after breast cancer (BC) treatment. A large proportion of these are estrogen/progesterone receptor-negative (ER-/PR-) and/or Her-2/neu overexpressing tumors. 131I radioablative therapy may provide a therapeutic alternative to treat metastases at this anatomic sanctuary since over 70% of invasive breast cancers, including a majority of ER- tumors and some brain metastases (unpublished data) express the sodium-iodide symporter (NIS). This approach relies on the success of radioiodide as a targeted treatment for thyroid cancers. To test this concept, we developed a BC BM model using tumor cells engineered to express NIS.
 Methods: MDAMB231 and SKBr3 cell lines were transduced with a lentiviral vector carrying a bicistronic cassette with NIS and the firefly luciferase (Fluc) genes separated by an internal ribosomal entry site. Single cell clones were selected and characterized for iodide uptake and bioluminescence. NIS-Fluc-MDAMB231 or NIS-Fluc SKBr3 cells (2.5 x 106 cells) were implanted subcutaneously (sc) in the mammary fat pad (mfp) of nude mice (NCr nude; 5-6 weeks old; n=5). NIS-Fluc mfp tumor xenografts were then explanted, 1x1 mm pieces excised and inserted stereotactically into the basal ganglia of the animal. All tumor development was monitored by serial in vivo bioluminescent imaging. Once established, brain tumors were excised, dissociated, established in tissue culture and re-implanted sc in the mfp of a new set of mice. Successive passages in the mfp then in the brain were performed in an attempt to increase tumor take. A second strategy tested with MDAMB231 cells consisted of direct implantation of cells into the basal ganglia. NIS expression was evaluated on tissue sections with a polyclonal antibody raised against the C-terminus of the human NIS.
 Results: All mice survived and were healthy in appearance. Intracranial implantation of mfp xenografts was highly successful with 66% take in both MDAMB231 (after two passages) and SKBr3 (after first passage). Bioluminescent imaging revealed sustained growth of tumors for more than 4 weeks. Microscopically, the explanted brain tumors had a cellular appearance without stromal cell or lymphocytic infiltration and were congruent with the histology of mfp xenografts. However, the tumor cell population was heterogeneous as NIS expression was present with plasma membrane staining in about 50% of SKBr3 and 15% of MDAMB231 cells. Direct cell implantations failed as no discernible bioluminescence was noted over a period of 3 weeks and no visible tumor at necropsy.
 Conclusions: A BCBM model has been developed by implanting intracranially mfp xenografts obtained with ER-/PR- +/- Her-2/neu overexpressing cells. Using this model, it will be possible to evaluate the effects of 131I on NIS-expressing BCBM.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2011.

Involvement of notch and RUNX pathways in human breast cancer

Abstract #6021

Background: Recent studies have demonstrated that the Notch signaling and the RUNX-mediated transcription pathways converge in mammalian hematopoiesis where they regulate proliferation and development. Evidence from in vitro experiments, mouse models and human tumors demonstrate that Notch signaling plays an oncogenic role in human breast cancer. Studies of RUNX factors involvement in human breast cancer suggest that the Core Binding Factor [CBF, a heterodimeric transcription factor composed of a RUNX DNA binding protein (RUNX1, RUNX2, or RUNX3) and a single non-DNA binding component termed CBFβ] participates in regulating the malignant phenotype of the tumor. Thus, the RUNX factors are primarily important to Notch signaling, and it seems likely that Notch:RUNX cross-talk will be important to cellular function and disease in a variety of tissue types. Here, we present our findings on cross-talk between Notch and RUNX pathways, which will lead to a better understanding of Notch and RUNX regulated transcription in breast carcinogenesis.
 Material and Methods: The expression and localization of the Notch1 NICD and RUNX2 in normal breast tissue and breast tumor were determined by immunohistochemistry on human breast tissue microarray obtained from Feist-Weiller Cancer Center. The expression profiles of Notch and RUNX were evaluated by real-time RT-PCR, Western Immunoblot, and electrophoretic mobility shift assay (EMSA).
 Results and Discussion: We found activated Notch1 and RUNX2 predominantly expressed in the cytoplasm and nucleus of cells in human normal breast tissues, respectively. However, in human breast cancer tissue samples, activated Notch1 was found in the nucleus in a high proportion of the cancer cells, while RUNX2 presence in the nucleus was much reduced and this could be due to mislocalization, over-expression or delayed degradation of the proteins. The major transcript in the breast cancer cell lines is RUNX1, but by EMSA, RUNX2 factor is the predominant biologically active and functional form of RUNX factors associated with breast cancer cell line-derived CBF. Transcript degradation and protein stability may play significant role in the regulation of RUNX factors in breast carcinogenesis. Down-regulation of CBFβ was found to affect Notch signaling in breast cancer cells and this may lead to the identification of new therapeutic targets for the successful treatment of breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 6021.

Controlled trials in hepatitis B virus-related decompensate liver cirrhosis: peripheral blood monocyte transplant versus granulocyte-colony-stimulating factor mobilization therapy

BACKGROUND

Liver cirrhosis represents the end stage of chronic liver injury. Currently, liver transplantation provides the only definite cure but it is beset with many problems, including lack of donors and risk of rejection. Stem cell therapy is very attractive in this setting because it has the potential to help tissue regeneration. In this study, we aimed to investigate the therapeutic effect of peripheral blood monocyte cell (PBMC) transplantation in decompensated liver cirrhosis.

METHODS

A total of 40 subjects (31 men and nine females, age range 21-71 years) was recruited to two groups. Group 1 received granulocyte-colony-stimulating factor (G-CSF) mobilization, PBMC collection by leukapheresis and PBMC transplant therapy. Group 2 received G-CSF mobilization for 4 days. At baseline and 6 months after treatment, liver function of the two groups was monitored by blood examination and ultrasonagraphy.

RESULTS

Both groups gained significant improvement in liver synthetic function, such as serum albumin and prothrombin time, from baseline to 6 months after treatment (P<0.01). However, there was no significant difference in alanine aminotransferase, aspartate aminotransferase and total bilirubin in both groups (P>0.05). Compared with group 2, a significantly improved liver function was observed in group 1, including elevated serum albumin level and a decreased CTP score (P<0.05). No major adverse effects were noted.

DISCUSSION

Autologous PBMC transplantation could be considered as a novel and alternative treatment for patients with decompensated liver cirrhosis.

Administration of intracoronary bone marrow mononuclear cells on chronic myocardial infarction improves diastolic function

BACKGROUND

Regeneration of the myocardium and improved ventricular function have been demonstrated in patients with acute myocardial infarction (MI) treated by intracoronary delivery of autologous bone marrow mononuclear cells (BMC) a few days after successful myocardial reperfusion by percutaneous coronary intervention (PCI); however, the effects of intracoronary cell infusion in chronic MI patients are still unknown.

AIMS

To investigate whether intracoronary infusion of BMC into the infarct-related artery in patients with healed MI could lead to improvement in left ventricular (LV) function.

METHODS

Among 47 patients with stable ischaemic heart disease due to a previous MI (13 (SD 8) months previously), 24 were randomised to intracoronary infusion of BMC (BMC group) and 23 to a saline infusion (control group) into the target vessel after successful PCI within 12 hours after chest pain occurred. LV systolic and diastolic function, infarct size and myocardial perfusion defect were assessed with the use of echocardiography, magnetic resonance imaging (MRI) or (201)Tl single-photon-emission computed tomography (SPECT) at baseline and repeated at the 6-month follow-up examination.

RESULTS

BMC treatment did not result in a significant increase in LV ejection fraction in any of the groups by any of the methods used, and the apparent tendency of an improvement was not statistically different between the two groups. The two groups also did not differ significantly in changes of LV end-diastolic and systolic volume, infarct size or myocardial perfusion. However, there was an overall effect of BMC transfer compared with the control group with respect to early/late (E/A) (p<0.001), early diastolic velocity/late diastolic (Aa) velocity (Ea/Aa) ratio (p = 0.002) and isovolumetric relaxation time (p = 0.038) after 6 months, as evaluated by tissue Doppler echocardiography. We noted no complications associated with BMS transfer.

CONCLUSION

Intracoronary transfer of autologous BMC in patients with healed MI did not lead to significant improvement of cardiac systolic function, infarct size or myocardial perfusion, but did lead to improvement in diastolic function.

Serological evidence of hepatitis E virus infection in an indigenous North American population

BACKGROUND

Hepatitis E virus (HEV) infections are thought to be uncommon in North America. Recently, HEV transmission has been reported following the consumption of deer meat. Because deer are closely related to caribou and caribou meat is a staple of the Canadian Inuit and the American Eskimo diet, the present study explored the seroprevalence of HEV infection in an isolated Canadian Inuit community.

METHODS

Stored sera were thawed and tested for immunoglobulin (Ig) G and IgM anti-HEV by ELISA, and tested for HEV-RNA by reverse transcriptase polymerase chain reaction.

RESULTS

The study consisted of 393 sera (representing approximately 50% of the community's inhabitants). Eleven samples (3%) were IgG anti-HEV-positive. Their mean age was 29+/-8 years and three were male. Two of 11 (18%) were also IgM anti-HEV-positive. All IgG anti-HEV-positive individuals were HEV-RNA-negative. Liver biochemistry was normal in all. Seven of 11 (64%) were also positive for anti-hepatitis A virus, five (46%) were hepatitis B virus seropositive and none (0%) were positive for anti-hepatitis C virus. There were no associations between infections with HEV and other hepatropic viruses. Serological testing was negative for HEV infection in 25 caribou from an adjacent region.

CONCLUSION

The results of the present study showed that serological evidence of HEV infection was present in 3% of the observed Canadian Inuit population; the presence of IgM anti-HEV suggested recent infection and HEV did not appear to coinfect with other common hepatotropic viruses. The source of HEV infection in the population remains unclear. These findings are interesting but preliminary. Additional data are required to determine whether HEV infections are responsible for otherwise unexplained acute hepatitis in the Canadian Inuit population and visitors returning from northern North American communities.

Nijmegen breakage syndrome 1 (NBS1) gene polymorphism and chemotherapy-induced neutropenic fever in breast cancer patients

574

Background: Neutropenic fever (NF) is a serious complication of the chemotherapies given to breast cancer patients and often limits their use. Hence, identifying which patients are at increased risk to develop NF is very important. The NBS1 gene product is important for the repair of double-strand DNA breaks and is activated by chemotherapy. The objective of this study was to determine if genetic variations of NBS1 polymorphisms predict the risk of chemotherapy-induced NF in breast cancer patients. Methods: Blood from 306 newly diagnosed breast cancer patients treated with chemotherapy were prospectively collected on a study approved by the institutional review board. The relationship of chemotherapy administration (e.g. dose, timing) and growth factor use were correlated with the absolute neutrophil count (ANC) and NF development. For each patient, we assessed three polymorphisms (924T>C, 8360G>C, and 30537G>C) of NBS1 gene using polymerase chain reaction-restriction fragment length polymorphism method. Two-sided Chi-square test was used for univariate analysis and a multivariable logistical regression analysis was used to calculate odds ratios. Results: In total, 167 (55%) patients experienced ANC less than 1,000 cells/microliter (CIN1000) and 30 (10%) patients developed NF. For 8360G>C polymorphism, 9.7% of patients had a 8360CC variant genotype and these patients had increased risk of NF than the other genotypes (NF in CC 20.7% vs. in others 8.1%; Odds Ratio [OR] = 3.0; 95% confidence interval [CI] = 1.1 - 8.0, p = 0.034). In multivariable logistic regression model, 8360CC genotype (OR = 5.0, 95% CI = 1.6 - 16.1, p = 0.007) and growth factor support (OR = 19.6, 95% CI = 4.4 - 87.6, p < 0.001) were significantly associated with NF development. No genotypes of 924T>C and 30537G>C polymorphisms increased the risk of NF and there was no statistical association between the three NBS1 gene polymorphisms and CIN1000. Conclusions: Breast cancer patients with 8360CC variant polymorphism in NBS1 gene have increased risk in developing NF with systemic chemotherapy. Analysis of polymorphisms of NBS1 and other DNA repair genes could potentially help identify who will develop chemotherapy-induced bone marrow toxicities.

No significant financial relationships to disclose.

Patterns of practice in radiation therapy for non-small cell lung cancer among members of American Society of Therapeutic Radiology and Oncology

7693

Purpose: To investigate the dominant pattern of current practice in radiation therapy (RT) for lung cancer among members of American Society of Therapeutic Radiology and Oncology (ASTRO). Methods: A 35-item survey was designed by a panel of 8 board certified radiation oncologists regarding RT for lung cancer. Surveys were sent through email to 3,800 radiation oncologist members on September 10, 2006, with the results collected online on December 10, 2006. Here we report results on radiation decisions for non-small cell lung cancer (NSCLC). Results: The response rate was 19% (n = 727). The respondents saw an average of 8 consults (ranged 1–25) monthly during the survey time (summing up to a total of >60,000 new cases yearly). For stage I peripherally located NSCLC, 33%, 10% and 20% of respondents reported conventional fractionated, hypofractioned and stereotactic RT, respectively. Another 25% of respondents would have offered stereotactic RT if this technique were available at their center. For stage I centrally located tumors, 78% of respondents did not agree with, but 10% selected, stereotactic RT. For stage II and III, 76% of respondents selected 60–70 Gy in 1.8–2 Gy with chemotherapy. With regard to the combined modality approach for stage II and III disease, 76–77% of respondents selected concurrent chemoRT followed by adjuvant chemotherapy, and 11–16% sequential followed by concurrent chemoRT for patients with good performance status. For stage IV NSCLC with remarkable local disease, the consideration of RT ranged from 0 Gy, 3 Gyx10, 3 Gyx15, 2.5 Gyx20, to 2 Gyx30 in 27%, 17%, 8%, 13%, and 21% of respondents, respectively. Conclusions: The dominant pattern of practice for stage II/III disease is concurrent chemoRT, consistent with results of phase III trials. The treatment decisions for stage I and IV disease are diverse, partially due to technology advancement and the lack of large phase III trials.

No significant financial relationships to disclose.