False Positive Uptake in Bilateral Gynecomastia on 68Ga-PSMA PET/CT Scan.

A 66-year-old man on hormonal therapy with prostate cancer was referred for Ga-PSMA PET/CT scan for biochemical recurrence. Ga-PSMA PET/CT scan detected moderate heterogeneous tracer concentration in bilateral breast parenchyma, in addition to the abnormal tracer concentration in enlarged prostate gland, right external iliac lymph node, and sclerotic lesion in L4 vertebra. On clinical examination, he was found to have bilateral gynecomastia. Abnormal concentration of Ga-PSMA in breast cancer is now well known, and in this context, it is important to know that tracer localization can occur in gynecomastia as well, as evidenced in this case.

Diagnostic Value of 68Ga PSMA-11 PET/CT Imaging of Brain Tumors-Preliminary Analysis.

OBJECTIVE: To evaluate the feasibility of using Ga PSMA-11 PET/CT for imaging brain lesions and its comparison with F-FDG. METHODS: Ten patients with brain lesions were included in the study. Five patients were treated cases of glioblastoma with suspected recurrence. F-FDG and Ga PSMA-11 brain scans were done for these patients. Five patients were sent for assessing the nature (primary lesion/metastasis) of space occupying lesion in brain. They underwent whole body F-FDG PET/CT scan and a primary site elsewhere in the body was ruled out. Subsequently they underwent Ga PSMA-11 brain PET/CT imaging. Target to background ratios (TBR) for the brain lesions were calculated using contralateral cerebellar uptake as background. RESULTS: In five treated cases of glioblastoma with suspected recurrence the findings of Ga PSMA-11 PET/CT showed good correlation with that of F-FDG PET/CT scan. Compared to the F-FDG, Ga PSMA-11 PET/CT showed better visualization of the recurrent lesion (presence/absence) owing to its significantly high TBR. Among the five cases evaluated for lesion characterization glioma and atypical meningioma patients showed higher SUVmax in the lesion with Ga PSMA-11 than with F-FDG and converse in cases of lymphoma. TBR was better with Ga PSMA PET/CT in all cases. CONCLUSION: Ga PSMA-11 PET/CT brain imaging is a potentially useful imaging tool in the evaluation of brain lesions. Absence of physiological uptake of Ga PSMA-11 in the normal brain parenchyma results in high TBR values and consequently better visualization of metabolically active disease in brain.

Fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography in a rare case of carcinoma stomach with concomitant silicosis.

The role of fluorine-18 fluorodeoxyglucose. (18F-FDG) positron emission tomography. (PET)/computed tomography. (CT) in the initial staging of various malignancies is now well established. However, nonspecificity of FDG occasionally results in tracer uptake in benign lung lesions. The authors describe a complicated case of carcinoma stomach with multiple nodules and a cavitary lesion in lungs where 18F-FDG PET CT done for initial staging revealed FDG avid mass in stomach, FDG avid multiple mediastinal lymph nodes and multiple intensely FDG avid bilateral lung lesions. The FDG avid lung lesions turned out to be due to silicosis as confirmed by histopathology.

Quality of life in patients with advanced non-small-cell lung cancer given maintenance treatment with pemetrexed versus placebo (H3E-MC-JMEN): results from a randomised, double-blind, phase 3 study.

BACKGROUND: Pemetrexed maintenance therapy significantly improved overall survival and progression-free survival compared with placebo, and had a good safety profile in a phase 3 placebo-controlled study in patients with advanced non-small-cell lung cancer (NSCLC). Results for quality of life, symptom palliation, and tolerability are presented here. METHODS: After four cycles of platinum-based induction therapy, 663 patients with stage IIIB or stage IV NSCLC and Eastern Cooperative Oncology Group performance status of 0 or 1 were randomly assigned (in a 2:1 ratio) from March 15, 2005, to July 20, 2007, using the Pocock and Simon minimisation method to receive pemetrexed (500 mg/m(2) every 21 days; n=441) or placebo (n=222) plus best supportive care until disease progression. The primary efficacy data have been reported previously. Patients completed the Lung Cancer Symptom Scale (LCSS) at baseline, after each cycle, and post-discontinuation. Worsening of symptoms was defined as an increase of 15 mm or more from baseline on a 100 mm scale for each LCSS item. The primary outcome for these quality-of-life analyses was time to worsening of symptoms, analysed for all randomised patients. This study is registered with ClinicalTrials.gov, number NCT00102804. FINDINGS: Baseline characteristics, including LCSS scores, were well balanced between groups. Baseline LCSS scores were low, indicating low symptom burden for patients without disease progression after completion of first-line treatment. Longer time to worsening was recorded for pain (hazard ratio [HR] 0·76, 95% CI 0·59-0·99; p=0·041) and haemoptysis (HR 0·58, 95% CI 0·34-0·97; p=0·038) with pemetrexed than with placebo; no other significant differences in analyses of time to worsening were noted. Additional longitudinal analyses showed a greater increase in loss of appetite in the pemetrexed group than in the placebo group (4·3 mm vs 0·2 mm; p=0·028). Rates of resource use were statistically higher for pemetrexed than for placebo: admissions to hospital for drug-related adverse events (19 [4%] vs none; p=0·001), transfusions (42 [10%] vs seven [3%]; p=0·003), and erythropoiesis-stimulating agents (26 [6%] vs four [2%]; p=0·017). INTERPRETATION: Quality of life during maintenance therapy with pemetrexed is similar to placebo, except for a small increase in loss of appetite, and significantly delayed worsening of pain and haemoptysis. In view of the improvements in overall and progression-free survival noted with pemetrexed maintenance therapy, such treatment is an option for patients with advanced non-squamous NSCLC who have not progressed after platinum-based induction therapy. FUNDING: Eli Lilly.

Randomized, double-blind, placebo-controlled phase II study of single-agent oral talactoferrin in patients with locally advanced or metastatic non-small-cell lung cancer that progressed after chemotherapy.

PURPOSE: To investigate the activity and safety of oral talactoferrin (TLF) in patients with stages IIIB to IV non-small-cell lung cancer (NSCLC) for whom one or two prior lines of systemic anticancer therapy had failed. PATIENTS AND METHODS: Patients (n = 100) were randomly assigned to receive either oral TLF (1.5 g in 15 mL phosphate-based buffer) or placebo (15 mL phosphate-based buffer) twice per day in addition to supportive care. Oral TLF or placebo was administered for a maximum of three 14-week cycles with dosing for 12 consecutive weeks followed by 2 weeks off. The primary objective was overall survival (OS) in the intent-to-treat (ITT) patient population. Secondary objectives included progression-free survival (PFS), disease control rate (DCR), and safety. RESULTS: TLF was associated with improvement in OS in the ITT patient population, meeting the protocol-specified level of significance of a one-tailed P = .05. Compared with the placebo group, median OS increased by 65% in the TLF group (3.7 to 6.1 months; hazard ratio, 0.68; 90% CI, 0.47 to 0.98; P = .04 with one-tailed log-rank test). Supportive trends were also observed for PFS and DCR. TLF was well tolerated and, generally, there were fewer adverse events (AEs) and grade ≥ 3 AEs reported in the TLF arm. AEs were consistent with those expected in late-stage NSCLC. CONCLUSION: TLF demonstrated an apparent improvement in OS in patients with stages IIIB to IV NSCLC for whom one or two prior lines of systemic anticancer therapy had failed and was well tolerated. These results should be confirmed in a global phase III trial.

A randomized, double-blind, placebo-controlled, phase II study of oral talactoferrin in combination with carboplatin and paclitaxel in previously untreated locally advanced or metastatic non-small cell lung cancer.

INTRODUCTION: The aim of the study is to investigate the activity and safety of oral talactoferrin (TLF) plus carboplatin and paclitaxel (C/P) in patients with previously untreated stage IIIB/IV non-small cell lung cancer. METHODS: Patients (n = 110) were randomly assigned to receive C/P plus either TLF (C/P/T) or placebo (C/P/P). The primary objective of this exploratory study was assessment of confirmed response rate (RR) in the prospectively defined evaluable population with a one-tailed p = 0.05. Secondary objectives included assessment of progression-free survival (PFS), duration of response, overall survival (OS), and safety. RESULTS: The trial met the primary end point of improvement in confirmed RR in the prospectively defined evaluable population. Compared with the C/P/P group, RR increased in the C/P/T group by 18% (29-47%; p = 0.05) and 15% (27-42%; p = 0.08) in the evaluable and intent-to-treat populations, respectively. Compared with the C/P/P group, the C/P/T group had a longer median PFS (4.2 versus 7.0 months), OS (8.5 versus 10.4 months), and duration of response (5.5 versus 7.6 months), although the differences were not statistically significant. Adverse events (AEs) were consistent with C/P therapy. There were fewer total AEs (472 versus 569; two-tailed p = 0.003) and grade 3/4 AEs (78 versus 105; p = 0.05) in the C/P/T group compared with the C/P/P group. CONCLUSION: TLF, in combination with C/P, demonstrated an apparent improvement in RR, PFS, and OS in patients with previously untreated stage IIIB/IV non-small cell lung cancer and appears to enhance activity without significant additional toxicity. These results need to be confirmed in a phase III trial.

In vivo temporal evolution of ALA-induced normalized fluorescence at different anatomical locations of oral cavity: application to improve cancer diagnostic contrast and potential.

BACKGROUND: The focal goal of this study is to identify optimal accumulation periods for ALA-induced PpIX in different healthy anatomical sites of human oral cavity and different types of abnormal mucosa to improve the accuracy of the clinical applications such as photodiagnosis and tissue grading. MATERIALS AND METHODS: Laser-induced fluorescence (LIF) emission spectra, with excitation at 404 nm from a diode laser, were recorded with a miniature fiber-optics spectrometer from 13 anatomical sites of oral mucosa in 15 healthy volunteers and 30 suspicious sites in 15 patients after topical application of 0.4% 5-ALA solution for 15 min. The optimal accumulation time in different anatomical sites of healthy subjects and abnormal tissues were determined by studying the temporal variation in normalized fluorescence intensities (NFI) at 635, 685 and 705 nm. RESULTS AND DISCUSSIONS: In masticatory anatomical locations such as (gingival and hard palate) and in lining mucosa (inner lip, soft palate, floor of mouth, transition to floor of mouth, alveolus and ventral tongue) except vermillion border of lip (VBL) of healthy subjects (designated as group I), it was observed that optimum time for maximum accumulation of PpIX is 90 min. In comparison, for lateral side of tongue (LST) and dorsal side of tongue (DST) tissues (designated as group II), maximum accumulation of PpIX was observed in 150 min of ALA application. For diverse grade lesions of group I mucosa in patients, maximum accumulation of PpIX was observed in 90 min, whereas, in group II mucosa the optimum accumulation time was 150 min as in the case of healthy mucosa. Further, between different grades oral mucosa, maximum variation in NFI take place at these optimal time periods. CONCLUSIONS: The determination of the optimum accumulation time of ALA in oral mucosa based on NFI helps to improve the diagnostic contrast and accuracy of oral cancer diagnosis, and to plan appropriate timing for ensuing PDT.

Diffuse reflection spectroscopy: an alternative to autofluorescence spectroscopy in tongue cancer detection.

Laser-induced autofluorescence (LIAF) and diffuse reflection spectroscopy (DRS) are two emerging noninvasive optical tools that have shown immense potential to detect oral cavity pre-cancer. In a recent study, we have used spectral ratio reference standards (SRRS) of LIAF intensity ratios F500/F635, F500/F685, and F500/F705 for grading of tissues belonging to sites other than dorsal side of tongue (DST), lateral side of tongue (LST), and vermillion border of lip (VBL) that exhibited similar spectral shape for normal and abnormal tissues. This led to dismal diagnostic accuracies, and for the three LIAF-SRRS, normal tissue values were often misclassified as squamous cell carcinoma (SCC), which means that the true negatives were being wrongly identified as true positives. This study examines the applicability of the site-specific diffuse reflection spectral intensity ratio (R545/R575) of the oxygenated hemoglobin bands to classify different DST lesions and compares the results obtained with those obtained using LIAF-SRRS. DRS-SRRS of R545/R575 differentiated benign hyperplastic DST tissues from normal tissue with a sensitivity of 86% and specificity of 80%, which were indistinguishable using LIAF-SRRS. Further, in distinguishing hyperplastic tissues from premalignant dysplastic lesions, DRS-SRRS gave a sensitivity of 90% and a specificity of 86%, as compared to sensitivity of 89% and specificity of 72% shown by the three LIAF-SRRS together. The diagnostic accuracy and statistical adequacy of the two techniques were assessed by receiver operating characteristic curve (ROC-Curve) analysis. Three LIAF ratios gave a low overall ROC area under curve (ROC-AUCs) of 0.521, whereas the DR ratio (R545/R575) has shown an improved accuracy of 0.970 in differentiating different tissue types. While distinguishing hyperplastic from dysplastic tissues, the DR ratio gave a higher discrimination accuracy of 0.9. Based on these findings, it can be concluded that the DRS-SRRS technique by virtue of its low cost and higher diagnostic accuracies could be a viable alternate to LIAF-SRRS for in vivo screening of tongue pre-cancers and grading of different tissue types.

Clinical grading of oral mucosa by curve-fitting of corrected autofluorescence using diffuse reflectance spectra.

BACKGROUND: Laser-induced autofluorescence (LIAF) and diffuse reflectance (DR) were collectively used in this clinical study to improve early oral cancer diagnosis and tissue grading. METHODS: LIAF and DR emission from oral mucosa were recorded on a fiber-optic spectrometer by illumination with a 404-nm diode laser and tungsten halogen lamp in 36 healthy volunteers and 40 lesions of 20 patients. RESULTS: Absorption dips in LIAF spectra at 545 and 575 nm resulting from changes in oxygenated hemoglobin were corrected using DR spectra of the same site. These corrected spectra were curve-fitted using Gaussian spectral functions to determine constituent emission peaks and their relative contribution. The Gaussian peak intensity and area ratios F500/F635 and F500/F685 were found to be useful indicators of tissue transformation. The diagnostic capability of various ratios in differentiating healthy, hyperplastic, dysplastic, and squamous cell carcinomas (SCCs) were examined using discrimination scatterplots. CONCLUSIONS: The LIAF/DR technique, in conjunction with curve-fitting, differentiates different grades of dysplasia and SCC in this clinical trial and proves its potential for early detection of oral cavity cancer and tissue grading.

Maintenance pemetrexed plus best supportive care versus placebo plus best supportive care for non-small-cell lung cancer: a randomised, double-blind, phase 3 study.

BACKGROUND: Several studies have shown the efficacy, tolerability, and ease of administration of pemetrexed-an antifolate antineoplastic agent-in patients with advanced non-small-cell lung cancer. We assessed pemetrexed as maintenance therapy in patients with this disease. METHODS: This randomised double-blind study was undertaken in 83 centres in 20 countries. 663 patients with stage IIIB or IV disease who had not progressed on four cycles of platinum-based chemotherapy were randomly assigned (2:1 ratio) to receive pemetrexed (500 mg/m(2), day 1) plus best supportive care (n=441) or placebo plus best supportive care (n=222) in 21-day cycles until disease progression. Treatment was randomised with the Simon and Pocock minimisation method. Patients and investigators were masked to treatment. All patients received vitamin B(12), folic acid, and dexamethasone. The primary endpoint of progression-free survival and the secondary endpoint of overall survival were analysed by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00102804. FINDINGS: All randomly assigned participants were analysed. Pemetrexed significantly improved progression-free survival (4.3 months [95% CI 4.1-4.7] vs 2.6 months [1.7-2.8]; hazard ratio [HR] 0.50, 95% CI 0.42-0.61, p<0.0001) and overall survival (13.4 months [11.9-15.9] vs 10.6 months [8.7-12.0]; HR 0.79, 0.65-0.95, p=0.012) compared with placebo. Treatment discontinuations due to drug-related toxic effects were higher in the pemetrexed group than in the placebo group (21 [5%] vs three [1%]). Drug-related grade three or higher toxic effects were higher with pemetrexed than with placebo (70 [16%] vs nine [4%]; p<0.0001), specifically fatigue (22 [5%] vs one [1%], p=0.001) and neutropenia (13 [3%] vs 0, p=0.006). No pemetrexed-related deaths occurred. Relatively fewer patients in the pemetrexed group than in the placebo group received systemic post-discontinuation therapy (227 [51%] vs 149 [67%]; p=0.0001). INTERPRETATION: Maintenance therapy with pemetrexed is well tolerated and offers improved progression-free and overall survival compared with placebo in patients with advanced non-small-cell lung cancer. FUNDING: Eli Lilly.

Discriminant analysis of autofluorescence spectra for classification of oral lesions in vivo.

BACKGROUND AND OBJECTIVES: Low survival rate of individuals with oral cancer emphasize the significance of early detection and treatment. Optical spectroscopic techniques are under various stages of development for diagnosis of epithelial neoplasm. This study evaluates the potential of a multivariate statistical algorithm to classify oral mucosa from autofluorescence spectral features recorded in vivo. STUDY DESIGN/METHODS: Autofluorescence spectra were recorded in a clinical trial from 15 healthy volunteers and 34 patients with diode laser excitation (404 nm) and pre-processed by normalization, mean-scaling and its combination. Linear discriminant analysis (LDA) based on leave-one-out (LOO) method of cross validation was performed on spectral data for tissue characterization. The sensitivity and specificity were determined for different lesion pairs from the scatter plot of discriminant function scores. RESULTS: Autofluorescence spectra of healthy volunteers consists of a broad emission at 500 nm that is characteristic of endogenous fluorophores, whereas in malignant lesions three additional peaks are observed at 635, 685, and 705 nm due to the accumulation of porphyrins in oral lesions. It was observed that classification design based on discriminant function scores obtained by LDA-LOO method was able to differentiate pre-malignant dysplasia from squamous cell carcinoma (SCC), benign hyperplasia from dysplasia and hyperplasia from normal with overall sensitivities of 86%, 78%, and 92%, and specificities of 90%, 100%, and 100%, respectively. CONCLUSIONS: The application of LDA-LOO method on the autofluorescence spectra recorded during a clinical trial in patients was found suitable to discriminate oral mucosal alterations during tissue transformation towards malignancy with improved diagnostic accuracies.

Oxygenated hemoglobin diffuse reflectance ratio for in vivo detection of oral pre-cancer.

Diffuse reflectance (DR) spectroscopy is a simple, low-cost, and noninvasive modality with potential for distinguishing oral precancer. Recently, in an ex vivo study, the DR spectral ratio (R545/R575) of oxygenated hemoglobin bands at 545 and 575 nm was used for grading malignancy. This work presents the results of clinical trials conducted in 29 patients to detect oral precancer using this ratio. We use site-specific normal spectra from a group of 36 healthy volunteers for comparison with those of patients. Toward this, in vivo DR spectra from 14 anatomical sites of the oral cavity of healthy volunteers are recorded on a miniature fiber optic spectrometer with white light excitation. The R545/R575 ratio is lowest for healthy tissues and appears to increase with the grade of malignancy. As compared to scatter plots that use the mean DR ratio from all anatomical sites, those using site-specific data show improved sensitivity and specificity for early diagnosis and grading of oral cancer. In the case of buccal mucosa, using scatter plots of R545/R575 ratio, we obtain a sensitivity of 100% and specificity of 86% for discriminating precancer (dysplasia) from hyperplasia, and a sensitivity of 97% and specificity of 86% for discriminating hyperplasia from normal.

Primary Adenoid Cystic Carcinoma Presenting as an Orbital Apex Tumor.

Primary adenoid cystic carcinoma occurring in the orbital apex is rare. We present the clinical features of a patient who initially presented with the clinical and radiologic features of an orbital pseudotumor. He developed features of orbital apex syndrome and repeat imaging showed a tumor of the orbital apex with intracranial invasion. He underwent radical skull base surgery and pathologic examination revealed adenoid cystic carcinoma in the orbital apex with a normal lacrimal apparatus. He received post operative radiation and the outcome in the light of a review of available literature is being discussed.

Glutathione S-transferase M1, T1 and P1 polymorphisms: susceptibility and outcome in lung cancer patients.

The glutathione S-transferases (GSTs) are a superfamily of genes whose products are phase II enzymes, catalyzing the conjugation of reactive intermediates to soluble glutathione. Some of the GSTs are polymorphic and may play a role in lung cancer susceptibility. We investigated whether genetic polymorphisms of GSTM1, GSTP1 and GSTT1 genes modulated lung cancer risk and affect survival among lung cancer patients. We determined the GST genotypes in 422 study subjects, using polymerase chain reaction (PCR) and reverse PCR and restriction fragment length polymorphism (RFLP). Logistic Regression analysis was carried out to find the association of various polymorphisms and GSTs and lung cancer. The influence of the genetic polymorphisms on patient survival was estimated using the method of Kaplan-Meier survival function. Cox Proportional Hazard models were used to estimate hazard ratios (HR) for deaths. GSTT1 -/- genotype conferred a higher odds ratio of 2.9 (P = 0.001) compared to the GSTT1+/+. So also, the GSTP1 GG genotype too had higher risk compared to the GSTP1 AA genotype (OR = 2.3, P = 0.033). When the combined GST M1, GSTT1 and GSTP1 genotypes were examined, patients with the combinations GSTM1 null and GSTT1 null had a significant OR of 3.6. So also the combinations GSTT1-/- GSTP1 AA (P = 0.005) and GSTT1-/- GSTP1 AG/GG (P = 0.001) came out to be significant. There were some significant interactions between GST genotypes with tobacco smoking and also for clinicopathological factors. Regarding survival analysis, no association of GSTM1 or GSTP1 genes with survival was noted. The GSTT1 -/- genotype along with stage was significantly associated with overall survival and found to be an independent prognostic factors for shorter lung cancer survival.

Laser-induced autofluorescence spectral ratio reference standard for early discrimination of oral cancer.

BACKGROUND: Laser-induced autofluorescence (LIAF) is an emerging noninvasive technique in the biomedical field, especially for cancer detection. The goal of the study was to develop a spectral ratio reference standard (SRRS) to discriminate different grades of oral cancer. METHODS: LIAF emission spectra from oral mucosa were recorded in the 420-720 nm spectral range on a miniature fiberoptic spectrometer from 14 anatomical sites of 35 healthy volunteers and 91 sites of 44 patients, with excitation at 404 nm from a diode laser. RESULTS: Histopathologic analysis of biopsy samples showed that oral mucosa of adjoining malignant sites in patients are not usually normal, but showed various degrees of epithelial dysplasia and hyperplasia. Therefore, instead of using LIAF data from apparently normal lesions of patients as control, spectral data values of the oral mucosa of healthy volunteers were used as control. The autofluorescence emission at 500 nm is characteristic of oral mucosa, whereas in malignant lesions a new peak is seen at 685 nm in addition to the previously reported peaks at 635 and 705 nm. Three spectral ratio reference standard (SRRS) scatterplots were created to differentiate the normal mucosa from hyperplasia, hyperplasia from dysplasia, and dysplasia from squamous cell carcinoma (SCC) using the mean fluorescence intensity ratios (F500/F635, F500/705 and F500/F685) measured from 40 sites in 20 patients and 11 sites in 35 healthy volunteers. During blind tests at 21 sites in 17 patients all 3 SRRS plots showed 100% sensitivity and specificity to discriminate hyperplasia from dysplastic and normal tissues, whereas only the F500/F685 SRRS showed the same sensitivity and specificity to differentiate dysplasia from SCC. CONCLUSIONS: An SRRS criteria based on scatterplots of autofluorescence spectral intensity ratios is described to discriminate oral mucosal variations and screen early stages of tissue progression toward malignancy.

p53 Arg72Pro polymorphism predicts survival outcome in lung cancer patients in Indian population.

In response to many forms of cellular stress, including DNA damage, the p53 protein functions to induce growth arrest, DNA repair, or apoptosis. Common allele variants in the TP53 gene modulate pathways of lung carcinogenesis and susceptibility to or prognosis of lung cancer. The prognostic role of the polymorphism was assessed in 422 subjects using PCR-RFLP. Logistic regression analysis showed a dominant presentation of Pro/Pro homozygotes in lung carcinoma population than in control population (OR = 2.1, P = 0.003). We further investigated the association of p53 codon 72 polymorphism with prognosis in 170 lung cancer patients. Kaplan-Meier survival analyses showed a significant difference in survival between p53 variant genotypes and overall survival (P = 0.02). Cox regression analysis showed p53 Arg72Pro heterozygous genotype was overall an independent prognostic factor (Risk ratio of death, 2.2; P = 0.02), suggesting Pro72Pro genotype to be a potential risk factor favoring the development of lung carcinoma and that Arg72Pro genotype is independently associated with a poorer prognosis of lung cancer.

Prognostic importance of DNA repair gene polymorphisms of XRCC1 Arg399Gln and XPD Lys751Gln in lung cancer patients from India.

PURPOSE: Inter individual variation in lung cancer susceptibility may be modulated in part through genetic polymorphisms in the DNA repair genes, especially the genes involved in the Base Excision Repair (BER) and nucleotide excision repair (NER) pathway. Two of the genetic polymorphisms, XRCC1Arg399Gln and XPD Lys751Gln have been extensively studied in the association with lung cancer risk, although published studies have been inconclusive. METHODS: In order to verify the role of the common variant alleles in the XPD gene, we have genotyped 211 lung cancer patients and 211 healthy controls using PCR-RFLP assays in a hospital based, case-control study in an Indian population. Logistic regression models were fit to examine the relationship between the log odds of lung cancer and each covariate. Overall Survival in relation to various genotypes and clinicopathological factors were analyzed using Kaplan Meier estimates and hazard ratios were calculated using Cox Regression analysis. RESULTS: The carriers of XRCC1 399 AA genotypes were at higher risk of lung cancer (OR = 2.1, 95% CI:1.224-3.669, P = 0.007) than carriers of GG genotype. Subjects carrying 751 AC genotype were at an increased risk of carcinoma of the lung (OR = 1.8; 95% CI:1.233-2.807, P = 0.003) than subjects with AA genotypes. Compared to the XRCC1 399 GG/ XPD 751 AA reference genotype, the combined variants, XRCC1 399 GG/ XPD 751 AC+CC (OR = 1.9, 95% CI: 1.037-3.481), P = 0.03), XRCC1 399 GA+AA/ XPD 751 AA (OR = 1.7, 95% CI: 1.020-2.833, P = 0.04), XRCC1 399 GA+AA/XPD 751 AC+CC (OR = 2.7, 95% CI: 1.582-4.864, P = 0.01), had significantly higher odds ratios. Increasing numbers of either XPD or XRCC1 variant alleles were associated with shorter overall survival, the risk being significant for the XRCC1 gene polymorphism (P = 0.01 by log-rank test). The hazard of dying was significant for the XRCC1 399 AA genotype (HR = 3.04, 95%CI: 1.393-6.670, P = 0.005). Higher tumour stage also came out as significant predictors of patient death. CONCLUSIONS: These findings suggest that genetic polymorphisms in the DNA repair genes may modulate overall lung cancer susceptibility and that pathological stage and XRCC1 Arg399Gln independently predicted overall survival among Indian lung cancer patients.

Possible risk modification by CYP1A1, GSTM1 and GSTT1 gene polymorphisms in lung cancer susceptibility in a South Indian population.

Susceptibility to lung cancer has been shown to be modulated by inheritance of polymorphic genes encoding cytochrome P450 1A1 (CYP1A1) and glutathione S transferases (GSTM1 and GSTT1), which are involved in the bioactivation and detoxification of environmental toxins. As the incidence of lung cancer is known to differ according to ethnicity, we have conducted a case-control study of 146 South Indian lung cancer patients along with 146 healthy controls, to assess any association between CYP1A1, GSTM1 and GSTT1 polymorphisms, either separately or in combination, with the likelihood of development of lung cancer in our population. The current weight of evidence from our study indicated that the frequency of CYP1A1 MspI homozygous variant alleles was significantly higher in cases (OR = 3.178). We observed a considerable difference in the GSTT1 null deletion frequency in this population when compared with other populations (OR = 2.472, 95% CI: 1.191-5.094, P = 0.014). There was no relative risk in GSTM1 null genotype when analysed singly (P = 0.453). Considering genotype combinations, risk of lung cancer increased remarkably significantly in individuals having one variant allele of CYP1A1, GSTM1, or GSTT1, suggesting gene-gene interactions. Rare genotypic combinations (such as CYP1A1 wild GSTM1 or GSTT1 either null; CYP1A1 variant both GSTM1 and GSTT1 present; CYP1A1 variant GSTM1 or GSTT1 either null), were at higher risk compared to the reference group. Moreover, patients who had smoked <20 pack years and harboured the CYP1A1 variant allele or the GSTT1 null genotype also had a significant risk of lung cancer. Hence our study-the first to analyse a South Indian population-suggests the importance of combined CYP1A1, GSTM1 and GSTT1 polymorphisms in the development of smoking-induced lung cancer.