Radiotherapy with or without mitomycin c in the treatment of locally advanced head and neck cancer: results of the IAEA multicentre randomised trial.

BACKGROUND AND PURPOSE: Single agent mitomycin c (MMC) has been shown to improve the outcome of radiotherapy in single institution trials. In order to confirm these findings in a broader worldwide setting, the International Atomic Energy Agency (IAEA) initiated a multicentre trial randomising between radiotherapy alone versus radiotherapy plus MMC. MATERIAL AND METHODS: Patients with advanced head and neck cancer were treated with primary curative radiotherapy (66 Gy in 33 fractions with five fractions per week) +/-a single injection (15 mg/m(2)) of MMC at the end of the first week of radiotherapy. Stratification parameters were tumour localization, T-stage, N-stage, and institution. A total of 558 patients were recruited in the trial from February 1996 to December 1999. Insufficient accrual and reporting led to the exclusion of three centres. The final study population consisted of 478 patients from seven centres. Patients had stage III (n=223) or stage IV (n=255) squamous cell carcinoma of the oral cavity (n=230), oropharynx (n=140), hypopharynx (n=65) or larynx (n=43). Prognostic factors like age, gender, site, size, differentiation and stage were well balanced between the two arms. RESULTS: The haematological side effects of MMC were very modest (<5% grade 3-4) and did not require any specific interventions. Furthermore, MMC did not enhance the incidence or severity of acute and late radiation side effects. Confluent mucositis and dry skin desquamation was common, occurring in 56% and 62% of patients, respectively. The overall 3-year primary locoregional tumour control, disease-specific and overall survival rates were 19, 36 and 30%, respectively. Gender, haemoglobin drop, tumour site, tumour and nodal stage were significant parameters for loco-regional tumour control. There was no significant effect of MMC on locoregional control or survival, except for the 161 N0 patients, where MMC resulted in a better loco-regional control (3-year estimate 16% vs. 29%, P=0.01). CONCLUSIONS: The study did not show any major influence of MMC on loco-regional tumour control, survival or morbidity after primary radiotherapy in stage III-IV head and neck cancer except in N0 patients where loco-regional control was significantly improved.     

Polymorphism in CYP1A1 and CYP2E1 genes and susceptibility to leukoplakia in Indian tobacco users

Inter-individual genetic differences may contribute to differences in susceptibility to human diseases triggered by environmental exposures. In this study, we investigated polymorphisms at two sites in the CYP1A1 and three sites in the CYP2E1 genes in 99 leukoplakia patients and 227 controls from one Indian population. The frequencies of genotypes at these polymorphic sites (MspI and Ileu/Val) in the CYP1A1 and (PstI, RsaI and DraI) in the CYP2E1 genes, were similar in patient and control groups. But the combined rare and heterozygous genotypes (CC+CD) at the DraI site in the CYP2E1 gene were over-represented among patients compared with controls (age-adjusted odds ratio (OR)=2.02, 95% confidence interval (CI)=1.21-3.35). Light tobacco smokers (i.e. <21 pack-year) and light tobacco chewers (i.e. <104 chewing-year) with a "rare" C allele at the DraI site had high risk of leukoplakia (OR=2.88, 95% CI=1.16-7.22; OR=2.94, 95% CI=1.15-7.65, respectively). The "mixed tobacco" users with "rare" C allele are more susceptible to the disease than "exclusive" tobacco smokers and chewers. The results indicate that the "rare" C allele at the DraI polymorphic site in CYP2E1 gene may enhance susceptibility to leukoplakia among tobacco users in this population. But the low sample size limited the power to precisely estimate the tobacco-genotype interactions.     

p16(INK4a) is a useful marker of human papillomavirus integration allowing risk stratification for cervical malignancies

The present study was conducted to assess utility of p16(INK4a) immunopositivity as a surrogate marker for genomic integration of high-risk human papillomavirus infection (hrHPV). A total of 29 formalin-fixed, paraffin-embedded cervical low-grade squamous intraepithelial lesions (LSILs), 27 high-grade squamous intraepithelial lesions (HSILs) and 53 invasive squamous cell carcinomas (SCCs), histologically-diagnosed between 1st January 2006 to 31st December 2008 at the University of Malaya Medical Centre were stained for p16(INK4a) (CINtec Histology Kit (REF 9511, mtm laboratories AG, Heidelberg, Germany). Immunopositvity was defined as diffuse staining of the squamous cell cytoplasm and or nucleus (involving > 75% of the intraepithelial lesions or SCCs). Staining of basal and parabasal layers of intraepithelial lesions was pre-requisite. One (3.4%) LSIL, 24 (88.9%) HSIL and 46 (86.8%) SCC were p16(INK4a) immunopositive. All normal squamous epithelium did not express p16(INK4). p16(INK4a) expression was significantly lower (p<0.05) in LSIL compared with HSIL and SCC with no difference in expression between HSIL and SCC.The increased p16(INK4a) immunopositivity in HSIL and SCC appears in line with the integrated existence of the hrHPV and may provide more insightful information on risk of malignant transformation of cervical squamous intraepithelial lesions than mere hrHPV detection.     

Quality of Life of Family Caregivers of Cancer Patients in a Developing Nation

Background: Quality of life (QOL) of family caregivers of cancer patients is usually affected due to increase in caregiver burden. Their QOL has not garnered much attention by many including the health professionals and community. This study aims to explore the QOL of family caregivers of cancer patients in a multi-ethnic country in Asia and to investigate its associate factors. Methods: This is a cross-sectional study where family caregivers and patients who were diagnosed of cancers within 12 months were recruited. QOL of caregivers were measured using The Caregiver Quality of Life Index-Cancer (CQOLC). Psychological distress was measured using Hospital anxiety and depressive scale. Logistic regression analysis was performed to determine the related factors of QOL of caregivers. Results: A total of 458 patients/caregiver pairs were included. Symptoms of anxiety and depression reported by caregivers were 24.9% and 24.2% respectively. Caregivers of patients with solid tumors have better CQOLC score compared to those who cared for patients with hematological cancers (91.25 vs 86.75). Caregivers of non-Malay ethnicity, those caring for patients with advanced stage cancer and with hematological cancers had significantly poorer QOL. QOL of caregivers are also significantly affected when patients demonstrated anxiety symptoms. Conclusion: This study provides detailed evaluation of the QOL of caregivers of cancer patients in Malaysia. The significant psychological distress and low caregiver QOL indicate the urgent need for comprehensive supports for caregivers with cancer patients, especially those caring for patients with haematological cancers.     

Down Regulated Expression Levels of miR-27b and miR-451a as a Potential Biomarker for Triple Negative Breast Cancer Patients Undergoing TAC Chemotherapy

Background: Triple negative breast cancer (TNBC) is associated with poor prognosis, aggressive phenotype(s) of tumours, partial chemotherapy response, and lack of clinically proven therapies. MicroRNAs (miRNAs) can target and modulate key genes that are involved in TNBC chemotherapy. Deregulated miRNA expression is highly involved in anti-cancer drug resistance phenotype and thus, miRNAs tend to be promising candidates for prediction of chemotherapy response and recurrence. Aim: This study aimed to investigate the expression levels of selected miRNAs (miR-21, miR-27b, miR-34a, miR-182, miR-200c and miR-451a) in cancerous and normal adjacent tissues of TNBC patients and to correlate with the clinicopathological data. Methods: Forty-one (41) FFPE tissue block of histopathologically confirmed TNBC patients was collected. Total RNA from the cancerous and adjacent non-cancerous tissues were isolated, transcribed, and pre-amplified. The relative expression level of miRNAs in tumour and normal adjacent tissues of TNBC patients was analysed using qRT-PCR. Results: Out of six miRNAs studied, the relative expression of miR-27b and miR-451a were found to be significantly lower in cancerous as compared to normal adjacent tissues of TNBC patients. In addition, a significant down regulation of miR-451a was also observed in infiltrating ductal carcinoma subtype, stages I and II, in both grade II and III, premenopausal and postmenopausal as well as in those with positive axillary lymph node metastases. Conclusion: The results suggest the possible utilization of miR-27b and miR-451a expression levels as potential predictive risk markers for TNBC patients undergoing TAC chemotherapy.     

Survival Rate and Prognostic Factors for Colorectal Cancer in Sabah,Borneo, Malaysia: A Retrospective Cohort of a Population-Based Study

Background: Colorectal cancer is a major public health problem with significant number of cases and death in the population. This study aimed to determine the 5-year overall survival rate and the prognostic factors for colorectal cancer patients in Sabah. Methods: This was a retrospective cohort study conducted using secondary data from Malaysian National Cancer Registry (MNCR) database. A 5-year overall survival and the median survival time were determined with Kaplan-Meier survival curve. Cox regression analysis was done to determine the prognostic factors on survival. Results: A total of 1,152 patients were included in this study. The majority of the patients had colon cancer and presented at late stage (stage III and IV) as compared to early stage (stage I and II). From the analysis, the 5-year overall survival for colorectal cancer was 23.2% (95% CI: 21.8, 24.6) and the median survival time was 16 months (95% CI: 14.3, 17.7).  Higher survivals are seen in males (23.6%, 95% CI: 20.4, 24.7), aged 50-74 years old (24.2%, 95% CI: 22.4, 26.0), Chinese (25.5%, 95% CI: 23.0, 28.0), lived in Keningau (25.6%, 95% CI: 20.8, 30.4), colon as primary tumor site (24.5%, 95% CI: 22.5, 26.4), diagnosed with stage I (55.6%, 95% CI: 48.7, 62.5) and received surgery with chemotherapy or radiotherapy (31.3%, 95% CI: 27.8, 34.8). The significant prognostic factor was the stage at diagnosis. Patients with stage IV colorectal cancer (HR: 11.18; 95% CI: 3.48, 35.93) had eleven times risk of dying as compared to stage I. Conclusion: The survival rate for colorectal cancer patients in Sabah was comparatively lower than other states in Malaysia and in some Asian countries. Those patients who presented at later stage had poorer survival. Health promotion and community-based screening program should be emphasized in addition to encouraging early diagnosis to improve survival.     

Potentiation of the antiproliferative activity of MKT-077 by loperamide, diltiazem and tamoxifen

MKT-077, a delocalized lipophilic cation, selectively targets cancer cells. MKT-077 has been reported to inhibit the growth of several tumor types and has undergone phase I clinical testing. We have examined the effect of MKT-077, alone and in combination with the antidiarrheal drug loperamide. Ten human cancer cell lines, four prostate (PC3, DU145, LNCaP, MDA-PCA-2B), two breast (MCF-7 and MDA-MB-231) and four colon (LoVo, Colo320DM, SW1116 and LS174t) were tested in vitro. Cells were grown to confluency prior to treatment. Loperamide potentiated the antiproliferative effect of MKT-077 in all ten cell lines, in a dose-dependent manner. The sensitivity of MDA-PCA-2B cells, the two breast and four colon cancer cell lines to MKT-077 was relatively low (>2.5 microg/ml MKT-077 required to inhibit growth by 95%). In these cell lines, 0.5-5 microg/ml (1-10 microM) loperamide caused a marked increase in the response to MKT-077. Loperamide is known to activate micro-opioid receptors at nanomolar concentrations and block voltage-gated calcium channels at micromolar doses. We found that calcium channel-blockers diltiazem and nifedipine (10-20 microg/ml), as well as tamoxifen (1.5-2.5 microg/ml) can also potentiate the growth-inhibitory effects of MKT-077. These synergistic interactions could be exploited for therapeutic benefit.     

Induction of p21 by p53 following DNA damage inhibits both Cdk4 and Cdk2 activities

DNA damage often activates the p53-p21 pathway and causes G(1)-phase arrest in mammalian cells. Although there is ample evidence that p21 induction by p53 leads to Cdk2 inhibition, it is unclear whether this checkpoint event also leads to Cdk4 inhibition. Diaminocyclohexane(trans-diacetato)(dichloro) platinum(IV) (DAP), a platinum-based coordination complex, is a DNA-damaging agent that is effective against a variety of tumor cells resistant to the parental drug cisplatin. Our previous studies established that treatment of human cancer cells with low effective concentrations of DAP specifically activates the G(1)-phase checkpoint and simultaneously inhibit Cdk4 and Cdk2 activities. Here we demonstrate that DAP treatment of human cancer cells activates the p53-p21 pathway without activating other known mechanisms that inhibit Cdk4 and Cdk2 activities. The induced p21 binds to both the Cdk4/cyclin D and Cdk2/cyclin E complexes and inhibits both of their kinase activities. Conversely, inhibition of p21 induction by cycloheximide or by p21 gene deletion prevents DAP-induced inhibition of Cdk4 and Cdk2 activities. Attenuated p53 expression and p21 induction also eliminates DAP-induced G(1)-phase arrest and inhibition of Cdk4 and Cdk2 activities. Together, these findings establish that activation of the p53-p21 pathway is responsible for the DAP-induced G(1)-phase checkpoint response and provide the first solid evidence that p21 induction by p53 during a DNA damage-induced G(1)-phase checkpoint response inhibits both Cdk4 and Cdk2 activities.     

Structure of the d(CGCGAATTCGCG)2 complex of the minor groove binding alkylating agent alkamin studied by mass spectrometry

Nitrogen mustard alkylating agents are important cancer drugs. Much interest has been focused on redirecting their covalent adducts from the N7 atoms of guanine in the major groove of DNA to the N3 atoms of adenine in the minor groove by attaching mustard groups to AT-selective minor groove binding ligands. Here we describe the use of electrospray ionization and matrix-assisted laser desorption ionization/time-of-flight mass spectrometry to study the structure of the DNA complexes of two minor groove binding polybenzamide mustards, alkamin and alkamini; the former is a bis-half-mustard in which reactive groups are disposed at each end of the ligand, and the latter is its monofunctional analog. Alkamin is potently cytotoxic and active in experimental mouse tumor models, whereas alkamini is not. We have studied their interaction with the DNA dodecamer d(CGCGAATTCGCG)(2), designated A2T2, and we provide a detailed analysis of the observed DNA-ligand adduct ions and their fragmentation products. We find that alkamini alkylates A2T2 at guanine G4 and adenines A5 and A6 in a manner consistent with covalent attack on purine N3 atoms from the minor groove of the AT tract. Alkamin also forms monofunctional adducts at G4 and both adenines in which the second mustard arm is hydrolyzed but, in addition, forms a variety of interstrand cross-links between adenines A5/A6 and A5'/A6', an interstrand cross-link between G4 and A6', and an intrastrand cross-link between G4 and A6. We conclude that the marked cytotoxicity of alkamin and its experimental antitumor activity could be the consequence of its ability to cross-link cellular DNA at AT tract sequences.     

Cigarette smoke-induced biochemical perturbations in human erythrocytes and attenuation by epigallocatechin-3-gallate--tea catechin

The protective effect of epigallocatechin-3-gallate (EGCG) against cigarette smoke (CS) induced alterations in human erythrocyte was studied using an in vitro model. Hemolysis, carboxyhemoglobin, osmotic fragility, hemin, lipid peroxidation (LPO), protein thiol, protein carbonyl, glutathione, antioxidant enzymes, membrane bound ATPases and erythrocyte ghost protein were assessed to investigate the effect of EGCG. Erythrocytes were incubated with CS and/or 10 μM EGCG under physiological conditions of temperature and pH for 2 h. CS significantly increased the percentage of hemolysis, carboxyhemoglobin, hemin, LPO and osmotic fragility in human erythrocytes whereas EGCG pretreatment significantly reduced all the above parameters. The levels of protein carbonyls significantly increased whereas the level of protein thiol decreased significantly in erythrocytes incubated with CS. EGCG pretreatment significantly decreased the levels of carbonyls and increased the level of protein thiol. The level of glutathione, antioxidant enzyme and membrane bound ATPases were decreased significantly in erythrocytes incubated with CS. However, EGCG pretreatment significantly increased the activities of GSH, antioxidant enzymes and membrane bound ATPases. CS incubated erythrocytes showed a progressive loss of the cytoskeleton proteins and formation of low molecular weight bands and protein aggregates. EGCG pretreatment of CS incubated erythrocytes showed a near normal protein profile compared to that of control erythrocytes. The present study divulges that EGCG can reduce the abnormalities of cigarette smoking by ameliorating the oxidative stress. This finding raises the possibility that EGCG may provide protection from CS induced toxicity.