Ionizing radiation-induced γ-H2AX activity in whole blood culture and the risk of lung cancer

BACKGROUND

Phenotypic biomarkers of DNA damage repair may enhance cancer risk prediction. The γ-H2AX formed at the sites of double-strand break (DSB) after ionizing radiation is a specific marker of DNA damage.

METHODS

In an ongoing case-control study, the baseline and ionizing radiation-induced γ-H2AX levels in peripheral blood lymphocytes (PBL) from frequency-matched 306 untreated patients with lung cancer and 306 controls were measured by a laser scanning cytometer-based immunocytochemical method. The ratio of ionizing radiation-induced γ-H2AX level to the baseline was used to evaluate interindividual variation of DSB damage response and to assess the risk of lung cancer by using unconditional multivariable logistic regression with adjustment of age, sex, ethnicity, smoking status, family history of lung cancer, dust exposure, and emphysema.

RESULTS

The mean γ-H2AX ratio was significantly higher in cases than controls (1.46 ± 0.14 vs. 1.41 ± 0.12, P < 0.001). Dichotomized at the median in controls, high γ-H2AX ratio was significantly associated with increased risk of lung cancer [OR = 2.43; 95% confidence interval (CI): 1.66-3.56]. There was also a significant dose-response relationship between γ-H2AX ratio and lung cancer risk in quartile analysis. Analysis of joint effects with other epidemiologic risk factors revealed elevated risk with increasing number of risk factors.

CONCLUSION

γ-H2AX activity as shown by measuring DSB damage in ionizing radiation-irradiated PBLs may be a novel phenotypic marker of lung cancer risk.

IMPACT

γ-H2AX assay is a robust and quantifiable image-based cytometer method that measures mutagen-induced DSB response in PBLs as a potential biomarker in lung cancer risk assessment.

Lymphaticovenular bypass surgery for lymphedema management in breast cancer patients

Historically, the reported incidence of upper extremity lymphedema in breast cancer survivors who have undergone axillary lymph node dissection has ranged from 9% to 41%. In the past 2 decades, sentinel lymph node biopsy has become popular as a way to minimize the morbidity associated with axillary dissection without compromising the cure rate for breast cancer patients. However, even with sentinel node biopsy, the postoperative incidence of upper limb lymphedema in breast cancer patients remains at 4-10%. Lymphedema occasionally emerges immediately after surgery but most often appears after a latent period. Obesity, postoperative seroma, and radiation therapy have been reported as major risk factors for upper extremity lymphedema, but the etiology of lymphedema is still not fully understood. Common symptoms of upper limb lymphedema are increased volume and weight of the affected limb and increased skin tension. The increased volume of the affected limb not only causes physical impairments in wearing clothes and in dexterity but also affects patients' emotional and mental status. Surgical management of lymphedema can be broadly categorized into physiologic methods and reductive techniques. Physiologic methods such as flap interposition, lymph node transfers, and lymphatic bypass procedures aim to decrease lymphedema by restoring lymphatic drainage. In contrast, reductive techniques such as direct excision or liposuction aim to remove fibrofatty tissue generated as a consequence of sustained lymphatic fluid stasis. Currently, microsurgical variations of lymphatic bypass, in which excess lymph trapped within the lymphedematous limb is redirected into other lymphatic basins or into the venous circulation, have gained popularity.

Association of polymorphisms in oxidative stress genes with clinical outcomes for bladder cancer treated with Bacillus Calmette-Guérin

Genetic polymorphisms in oxidative stress pathway genes may contribute to carcinogenesis, disease recurrence, treatment response, and clinical outcomes. We applied a pathway-based approach to determine the effects of multiple single nucleotide polymorphisms (SNPs) within this pathway on clinical outcomes in non-muscle-invasive bladder cancer (NMIBC) patients treated with Bacillus Calmette-Guérin (BCG). We genotyped 276 SNPs in 38 genes and evaluated their associations with clinical outcomes in 421 NMIBC patients. Twenty-eight SNPs were associated with recurrence in the BCG-treated group (P<0.05). Six SNPs, including five in NEIL2 gene from the overall and BCG group remained significantly associated with recurrence after multiple comparison adjustments (q<0.1). Cumulative unfavorable genotype analysis showed that the risk of recurrence increased with increasing number of unfavorable genotypes. In the analysis of risk factors associated with progression to disease, rs3890995 in UNG, remained significant after adjustment for multiple comparison (q<0.1). These results support the hypothesis that genetic variations in host oxidative stress genes in NMIBC patients may affect response to therapy with BCG.

Systematic evaluation of apoptotic pathway gene polymorphisms and lung cancer risk

We adopted a two-stage study design to screen 927 single nucleotide polymorphisms (SNPs) located in 73 apoptotic-pathway genes in a case-control study and then performed a fast-track validation of the significant SNPs in a replication population to identify sequence variations in the apoptotic pathway modulating lung cancer risk. Fifty-five SNPs showed significant associations in the discovery population comprised of 661 lung cancer cases and 959 controls. Six of these SNPs located in three genes (Bcl-2, CASP9 and ANKS1B) were validated in a replication population with 1154 cases and 1373 controls. Additive model was the best-fitting model for five SNPs (rs1462129 and rs255102 of Bcl-2, rs6685648 of CASP9 and rs1549102, rs11110099 of ANKS1B) and recessive model was the best fit for one SNP (rs10745877 of ANKS1B). In the analysis of joint effects with subjects carrying no unfavorable genotypes as the reference group, those carrying one, two, and three or more unfavorable genotypes had an odds ratio (OR) of 2.22 [95% confidence interval (CI) = 1.08-4.57, P = 0.03], 2.70 (95% CI = 1.33-5.49; P = 0.006) and 4.13 (95% CI = 2.00-8.57; P = 0.0001), respectively (P for trend = 6.05E-06). The joint effect of unfavorable genotypes was also validated in the replication population. The SNPs identified are located in or near key genes known to play important roles in apoptosis regulation, supporting the strong biological relevance of our findings. Future studies are needed to identify the causal SNPs and elucidate the underlying molecular mechanisms.

Female urethral reconstruction using a tubed rectus abdominis myocutaneous flap

We describe the novel use of a rectus abdominis myocutaneous flap for reconstruction of the female urethra following an oncological pelvic resection. Reconstruction of the female urethra from the bladder neck to external urethral orifice was successfully performed, avoiding the need for a urostomy. To our knowledge, the myocutaneous flap has never been described for complete urethral reconstruction.

Multistage analysis of variants in the inflammation pathway and lung cancer risk in smokers

BACKGROUND

Tobacco-induced lung cancer is characterized by a deregulated inflammatory microenvironment. Variants in multiple genes in inflammation pathways may contribute to risk of lung cancer.

METHODS

We therefore conducted a three-stage comprehensive pathway analysis (discovery, replication, and meta-analysis) of inflammation gene variants in ever-smoking lung cancer cases and controls. A discovery set (1,096 cases and 727 controls) and an independent and nonoverlapping internal replication set (1,154 cases and 1,137 controls) were derived from an ongoing case-control study. For discovery, we used an iSelect BeadChip to interrogate a comprehensive panel of 11,737 inflammation pathway single-nucleotide polymorphisms (SNP) and selected nominally significant (P < 0.05) SNPs for internal replication.

RESULTS

There were six SNPs that achieved statistical significance (P < 0.05) in the internal replication data set with concordant risk estimates for former smokers and five concordant and replicated SNPs in current smokers. Replicated hits were further tested in a subsequent meta-analysis using external data derived from two published genome-wide association studies (GWAS) and a case-control study. Two of these variants (a BCL2L14 SNP in former smokers and an SNP in IL2RB in current smokers) were further validated. In risk score analyses, there was a 26% increase in risk with each additional adverse allele when we combined the genotyped SNP and the most significant imputed SNP in IL2RB in current smokers and a 36% similar increase in risk for former smokers associated with genotyped and imputed BCL2L14 SNPs. CONCLUSIONS/IMPACT: Before they can be applied for risk prediction efforts, these SNPs should be subject to further external replication and more extensive fine mapping studies.

Abstract 4484: A novel objective, image-based phenotypic assay reveals higher α-radiation-induced γ-H2AX level in peripheral blood lymphocytes as a risk predictor for lung cancer

Intermediate phenotypic biomarker measures the summary results of genetic variations and may enhance predictive power in cancer risk assessment. In this study, we developed a novel objective, image-based phenotypic assay to measure α-radiation induced DNA double strand breaks (DSBs) in peripheral blood lymphocytes (PBLs) and used it as a potential biomarker for lung cancer risk prediction. γ-H2AX formation in the chromatin flanking DNA DSBs is one of the most sensitive DNA damage markers. In an ongoing lung cancer case-control study, the baseline and α-radiation-induced γ-H2AX immunofluorescence intensities in the PBLs from 403 untreated lung cancer patients and 307 controls subjects were assessed, and the ratio of the induced γ-H2AX level to the baseline γ-H2AX level was used as a variable to evaluate the sensitivity to mutagen challenge. The mean γ-H2AX ratio was significantly higher in cases than controls (case vs. control: 1.46±0.14 vs. 1.41±0.12, p &lt; 0.001). A significantly decreasing trend in γ-H2AX ratio with age was observed for both cases (p for trend =0.003) and controls (p for trend =0.011). Dichotomized at the median level of the γ-H2AX ratio in controls, individuals with high ratio exhibited a significantly increased risk of lung cancer (OR=2.33, 95%CI: 1.67-3.23). There was also a dose-response relationship with lung cancer risk in tertile and quartile analysis (p for trend &lt; 0.001 for both). Analysis of the joint effects of risk factors revealed an apparently elevated risk of lung cancer for subjects with a higher γ-H2AX ratio who were ever smokers, compared with subjects with a low ratio who were never smokers (OR=12.68, 95%CI: 6.84-23.51, p &lt; 0.001). This is the first study applying relative quantification of the γ-H2AX level in PBL to assess the risk for developing lung cancer. Susceptibility to DNA DSBs might help to identify individuals at high risk for this cancer. α-radiation-induced DNA damage as determined with the new γ-H2AX assay could be a novel phenotypic risk factor of lung cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4484. doi:1538-7445.AM2012-4484

Surgical management of lymphedema: past, present, and future

Recent advances in surgical management of lymphedema have provided options for patients who have failed conservative management with manual lymphatic massage and/or compression garments. The purpose of this review is to provide a historical background to the surgical treatment of lymphedema and how these options have evolved over time. In addition, we aim to delineate the various types of surgical approaches available, indications for surgery, and reported outcomes. Our goal is to increase awareness of these options and foster research to improve their outcomes.

Genetic variants in TGF-β pathway are associated with ovarian cancer risk

The transforming growth factor-β (TGF-β) signaling pathway is involved in a diverse array of cellular processes responsible for tumorigenesis. In this case-control study, we applied a pathway-based approach to evaluate single-nucleotide polymorphisms (SNPs) in the TGF-β signaling pathway as predictors of ovarian cancer risk. We systematically genotyped 218 SNPs from 21 genes in the TGF-β signaling pathway in 417 ovarian cancer cases and 417 matched control subjects. We analyzed the associations of these SNPs with ovarian cancer risk, performed haplotype analysis and identified potential cumulative effects of genetic variants. We also performed analysis to identify higher-order gene-gene interactions influencing ovarian cancer risk. Individual SNP analysis showed that the most significant SNP was SMAD6: rs4147407, with an adjusted odds ratio (OR) of 1.60 (95% confidence interval [CI], 1.14–2.24, P = 0.0066). Cumulative genotype analysis of 13 SNPs with significant main effects exhibited a clear dose-response trend of escalating risk with increasing number of unfavorable genotypes. In gene-based analysis, SMAD6 was identified as the most significant gene associated with ovarian cancer risk. Haplotype analysis further revealed that two haplotype blocks within SMAD6 were significantly associated with decreased ovarian cancer risk, as compared to the most common haplotype. Gene-gene interaction analysis further categorized the study population into subgroups with different ovarian cancer risk. Our findings suggest that genetic variants in the TGF-β signaling pathway are associated with ovarian cancer risk and may facilitate the identification of high-risk subgroups in the general population.

Percutaneous selective radiofrequency nerve ablation for glabellar frown lines

BACKGROUND

The dynamic muscles of the glabellar region can be overactive, giving patients a "scowling" look and making them appear angry, worried, or stressed.

OBJECTIVE

The authors describe percutaneous selective nerve ablation, a minimally-invasive procedure for treatment of glabellar frown lines, and report results from a series of patients treated with the technique.

METHODS

From November 2007 to December 2009, 27 patients (22 women and five men) underwent percutaneous selective nerve ablation to improve glabellar frown lines. Initially, the surface pathway of the nerve to the corrugator supercilii and procerus was checked with a peripheral nerve stimulator. For percutaneous localization, a 22-gauge monopolar electrode was introduced into the lateral brow and cheek skin without incision. Short electrical stimulation (0.3-0.5 mA) was delivered to identify the proper lesion sites. Synchronous contraction of corrugator supercilii was elicited and radiofrequency nerve ablation performed (85°C, 70 seconds). In all patients, the frontal branch of the facial nerve and angular nerve were treated bilaterally. The improvement was evaluated with the Wrinkle Assessment Scale.

RESULTS

Mean patient age was 54.5 years, and mean follow-up time was 18 months (range, 12-26 months). One patient had superficial second-degree burns to the brow skin, which healed with conservative treatment. Two patients had temporary paresthesia that completely resolved in a few weeks without sequelae. The Wrinkle Assessment Scale indicated a statistically significant improvement in the glabellar frown lines (preoperative vs postoperative mean, 3.7 vs 1.8; P < .05).

CONCLUSIONS

Although long-term studies are necessary to determine the ideal amount of energy delivery for maximum efficacy and time for treatment of glabellar frown lines, the study lends support for the safety and efficacy of percutaneous selective nerve ablation.

Variants in inflammation genes are implicated in risk of lung cancer in never smokers exposed to second-hand smoke

Lung cancer in lifetime never smokers is distinct from that in smokers, but the role of separate or overlapping carcinogenic pathways has not been explored. We therefore evaluated a comprehensive panel of 11,737 single-nucleotide polymorphisms (SNP) in inflammatory-pathway genes in a discovery phase (451 lung cancer cases, 508 controls from Texas). SNPs that were significant were evaluated in a second external population (303 cases, 311 controls from the Mayo Clinic). An intronic SNP in the ACVR1B gene, rs12809597, was replicated with significance and restricted to those reporting adult exposure to environmental tobacco smoke. Another promising candidate was an SNP in NR4A1, although the replication OR did not achieve statistical significance. ACVR1B belongs to the TGFR-β superfamily, contributing to resolution of inflammation and initiation of airway remodeling. An inflammatory microenvironment (second-hand smoking, asthma, or hay fever) is necessary for risk from these gene variants to be expressed. These findings require further replication, followed by targeted resequencing, and functional validation.

Skull base reconstruction in the pediatric patient

Tumors of the skull base are rare in children and adolescents and present a complicated management problem for oncologists and surgeons alike. Surgical resection is an integral component of the management of many pediatric neoplasms, especially those that are benign or, though not frankly malignant, are locally invasive. The general principles of skull base reconstruction following tumor ablation are applicable to nearly all patients; the reconstructive algorithm, however, is particularly complex in the pediatric population and the potential benefits of therapy must be balanced against the cumulative impact on craniofacial growth and maturity and the donor site morbidity. A retrospective analysis of all patients less than 19 years of age who underwent resection of a skull base tumor was performed. Particular emphasis was placed on the 12 patients who required complex reconstruction by the plastic surgical service. This represents approximately a third of the operated patients. Data were recorded on patient age, tumor pathology and location, prior therapies, surgical approach, extent of resection, margin status, defect components, details of reconstructive methods employed, complications, additional procedures or interventions, and the use and timing of adjuvant therapies. Patient outcome at most recent follow-up was recorded. All patients were followed clinically and by MRI and/or CT scan of the skull base. The reconstructive details recorded included flap choice, recipient vessels, and any concomitant procedures performed. The indications for and details of any staged surgical revisions or prosthetics were also noted. Complications recorded included partial or total flap loss, cerebrospinal fluid leakage, meningitis, infection, abscess, hematoma or seroma formation, delayed healing, and donor site dysfunction. The vertical rectus abdominis myocutaneous free flap was the most common means of reconstruction utilized in this series. Three of 12 patients had reconstruction related complications. Delayed reconstructive procedures or prosthetic interventions have been performed in 6 of the 12 patients who underwent complex reconstructions. On the basis of our experience and previous reports in the literature, we offer the following guidelines for the successful multidisciplinary care of children and adolescents undergoing skull base reconstruction after tumor resection: (1) skull base reconstruction may be safely performed in children and adolescents using free tissue transfer or local flaps; (2) larger defects and those involving more than one anatomic region of the skull base should be repaired with soft-tissue free flaps; and (3) because of the versatility and reliability of free flaps, pedicled flaps should be reserved for limited defects. Because of the potentially synergistic effects of multimodality treatment for skull base malignancies on craniofacial growth and development, we advocate soft-tissue reconstruction as the primary technique, reserving bony flaps for definitive procedures in survivors who have reached skeletal maturity.

Abstract 5475: Wnt pathway pharmacogenetics in lung cancer patients treated with platinum regimens

Background: The Wnt/β-catenin signaling is important in the development and progression of non-small cell lung cancer (NSCLC). Expression of Wnt pathway components was common in resected NSCLC and was associated with poor prognosis. Moreover, Wnt pathway expression in NSCLC cell lines correlated with increased cell growth and resistance to therapy. The host genotype may modulate the effect of individual biological factors on treatment and clinical outcome. Hence, we assessed Wnt pathway pharmacogenetics in patients with advanced NSCLC receiving platinum-based therapy.

Method: Peripheral blood mononuclear cells (PBMCs) were collected from 598 inoperable stage III-IV NSCLC patients receiving platinum regimens. Genomic DNA was extracted from PBMCs and stored at -80o C. Illumina's Infinium iSelect HD Custom Genotyping BeadChip (Illumina, San Diego, CA) standard 3 day protocol was used to assess 441 host SNPs in 50 candidate Wnt pathway genes. BeadStudio software was used to autocall genotypes. SNPs with a call rate &lt;95% were excluded from further analysis. Cox's proportional hazards model was used to estimate Hazard Ratios (HRs), with adjustment for age, sex, ethnicity, smoking status, clinical stage, performance status and therapy modality. The most common genotype served as the reference group. To correct for the effect of multiple comparisons, q values (a false discovery rate [FDR] adjusted P-value) were calculated by a method implemented in the R package. SNPs with q&lt;0.10 were then used in the assessments of the combined effects of unfavorable genotypes. Survival tree analysis was performed to assess higher-order gene-gene interactions,

Results: Survival correlated with 57 SNPs from 21 genes. After correcting for multiple comparisons, five SNPs remained significant in multivariate analysis, including the AXIN2 SNPs rs11868547 (Hazard Ratio [HR] for variant vs. reference SNP =0.77 [95% CI, 0.66-0.89], p=0.0006) and rs4541111 (HR=0.77 [0.68-0.91], p&lt;0.002), as well as rs12819505 (Wnt-5B, HR=1.58 [1.19-2.09], p&lt;0.002), rs4413407 (CXXC4, HR=1.28 [1.10-1.50], p&lt;0.002), and rs10878232 (WIF-1, HR=1.36 [1.12-1.66], p&lt;0.003). Cumulative analysis of these SNPs showed the joint effects of unfavorable genotypes on patient survival. Survival tree analysis based on four of these SNPs revealed higher order gene-gene interactions and classified patients into two groups of low and high death risk, with median survival time of 17.3 and 11.3 months respectively (log rank p&lt; 5 × 10−8).

Conclusions: Wnt pathway SNPs were significantly associated with survival of NSCLC patients treated with platinum-based chemotherapy. This supports published data suggesting that the Wnt pathway plays an important role in affecting clinical outcome for NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5475. doi:10.1158/1538-7445.AM2011-5475

The use of free flap for limb salvage in children with tumors of the extremities

BACKGROUND

The purpose of this study was to evaluate long-term functional outcomes in pediatric oncology patients who underwent limb salvage using free flaps.

METHODS

All 22 pediatric oncology patients treated with a free flap for extremity salvage were included in the study from 1999 to 2008.

RESULTS

The median patient age was 13.5 years. All but one patient had sarcoma, which involved lower extremity in 45% and upper extremity in 55%. The median bone defect length was 13.9 cm: reconstructed with vascularized free fibula in 68% (in 23% osseous allograft was also used) and used fibula growth plate transfer in 23%. The mean soft tissue defect area was 108 cm(2): reconstructed with latissimus dorsi flap in 4 patients, vertical rectus abdominus muscle flap in 2, and anterolateral thigh flap in 1. The majority of the complications were nonunion (14%) and wound infection/dehiscence (14%). The median Musculoskeletal Tumor Society score was 70. Patients with tumors in the upper extremity had significantly higher Musculoskeletal Tumor Society scores compared with lower extremity tumor patients (80 vs 50, P = .04); and among those with lower extremity tumors, patients with distal defects had better outcomes than patients with proximal defects (70 vs 40, P = .03).

CONCLUSION

In pediatric oncology patients who need limb salvage, use of free flaps can result in good long-term functional outcomes.

Muscle and omental flaps for chest wall reconstruction

Reconstruction of the chest wall represents an important part of a patient's treatment following resection of various thoracic tumors. Many different types of flaps, including both pedicled and free flaps, have been described for use in chest wall reconstruction. These reconstructions are most effectively managed with a multidisciplinary approach involving plastic and cardiothoracic surgery. The pectoralis major, latissimus dorsi, rectus abdominis, trapezius, and external oblique muscles and the omentum are all local options that can play an important role in the reconstruction of the chest wall.

Genetic variants in MicroRNA biosynthesis pathways and binding sites modify ovarian cancer risk, survival, and treatment response

MicroRNAs (miRNA) play important roles in tumorigenesis. Genetic variations in miRNA processing genes and miRNA binding sites may affect the biogenesis of miRNA and the regulatory effect of miRNAs to their target genes, hence promoting tumorigenesis. This study analyzed 226 single nucleotide polymorphisms (SNP) in miRNA processing genes and miRNA binding sites in 339 ovarian cancer cases and 349 healthy controls to assess association with cancer risk, overall survival, and treatment response. Thirteen polymorphisms were found to have significant association with risk. The most significant were 2 linked SNPs (r(2) = 0.99), rs2740351 and rs7813 in GEMIN4 [odds ratio (OR) = 0.71; 95% confidence interval (CI), 0.57-0.87 and OR = 0.71; 95% CI, 0.57-0.88, respectively]. Unfavorable genotype analysis showed the cumulative effect of these 13 SNPs on risk (P for trend < 0.0001). Potential higher order gene-gene interactions were identified, which categorized patients into different risk groups according to their genotypic signatures. In the clinical outcome study, 24 SNPs exhibited significant association with overall survival and 17 SNPs with treatment response. Notably, patients carrying a rare homozygous genotype of rs1425486 in PDGFC had poorer overall survival [hazard ratio (HR) = 2.69; 95% CI, 1.67-4.33] and worse treatment response (OR = 3.38; 95% CI, 1.39-8.19), compared to carriers of common homozygous and heterozygous genotypes. Unfavorable genotype analyses also showed a strong gene-dosage effect with decreased survival and increased risk of treatment nonresponse in patients with greater number of unfavorable genotypes (P for trend < 0.0001). Taken together, miRNA-related genetic polymorphisms may impact ovarian cancer predisposition and clinical outcome both individually and jointly.

Genetic variations in regulator of G-protein signaling genes as susceptibility loci for second primary tumor/recurrence in head and neck squamous cell carcinoma

Curatively treated patients with early-stage head and neck squamous cell carcinoma (HNSCC) are at high risks for second primary tumor (SPT) and recurrence. The regulator of G-protein signaling (RGS) is important in essential signaling transduction and cellular activities. We hypothesize that genetic variations of RGS may modulate the risk of SPT/recurrence in patients with early-stage HNSCC. In a nested case-control study, we evaluated 98 single-nucleotide polymorphisms (SNPs) in 17 RGS genes for the risk of SPT/recurrence among 450 HNSCC patients. Eight SNPs showed significant associations with the risk of SPT/recurrence, with the most significant one of rs2179653, which is located in the 5'-flanking region of RGS2 gene. Under a recessive genetic model, the homozygous variant genotype of this SNP was associated with 2.95-fold [95% confidence interval (CI): 1.52-5.74] increased risk of SPT/recurrence. This association remained significant after the adjustment for multiple comparisons. Cumulative effects analysis revealed that the risk increased significantly with the increasing numbers of unfavorable genotypes. Compared with subjects carrying 0-2 unfavorable genotypes, the hazard ratios (95% CIs) for those carrying 3 or 4+ were 1.73 (1.10-2.70) and 3.05 (1.92-4.83), respectively. Furthermore, survival tree analysis revealed potential higher order gene-gene interactions and indicated different outcomes based on distinct genotype profiles. Genetic variations of RGS genes may modulate the susceptibility to SPT/recurrence in early-stage HNSCC patients individually and cumulatively. Our results stressed the importance of taking a polygenic approach to evaluate the cumulative and interaction effects of genetic variations in the prediction of cancer risk and prognosis.

Randomized phase II trial evaluation of erectile function after attempted unilateral cavernous nerve-sparing retropubic radical prostatectomy with versus without unilateral sural nerve grafting for clinically localized prostate cancer

BACKGROUND

Nonrandomized studies of unilateral nerve-sparing (UNS) radical prostatectomy (RP) have reported improved recovery of erectile function if the sacrificed cavernous nerve is reconstructed with a sural nerve graft (SNG).

OBJECTIVE

To determine whether UNS RP plus SNG results in a 50% relative increase in potency at 2 yr compared to UNS RP alone.

DESIGN, SETTING, AND PARTICIPANTS

The study enrolled patients from October 2001-May 2006 from a single academic center and was randomized, open label. Participants were men with localized prostate cancer recommended for UNS RP, less than 66 yr old, normal baseline erectile function, and willing to participate in early erectile dysfunction (ED) therapy. Patients were followed up to 2 yr.

INTERVENTION

Patients underwent UNS RP and ED therapy starting at 6 wk: oral prostaglandin type-5 (PDE5) inhibitor, vacuum erection device (VED), and intracavernosal injection therapy. In the SNG group, a plastic surgeon performed the procedure at the time of RP.

MEASUREMENTS

The ability to have an erection suitable for intercourse with or without a PDE5 inhibitor at 2 yr. The hypothesis was that SNG would result in a 60% potency rate compared to 40% for controls (80% power, 5% two-way significance).

RESULTS AND LIMITATIONS

The trial planned to enroll 200 patients, but an interim analysis at 107 patients met criteria for futility and the trial was closed. For patients completing the protocol to 2 yr, potency was recovered in 32 of 45 (71%) of SNG and 14 of 21 (67%) of controls (p=0.777). By intent-to-treat analysis, potency recovered in 32 of 66 (48.5%) of SNG and 14 of 41 (34%) of controls (p=0.271). No differences were seen in time to potency or quality of life scores for ED and urinary function. Limitations included slower-than-expected accrual and poor compliance with ED therapy: <65% for VED and <40% for injections.

CONCLUSIONS

The addition of SNG to a UNS RP did not improve potency at 2 yr following surgery.

TRIAL REGISTRATION

ClinicalTrials.gov, Identifier: NCT00080808, http://www.clinicaltrials.gov/ct2/show/NCT00080808?term=NCT00080808&rank=1.

Pediatric mandibular reconstruction using a vascularized fibula flap

BACKGROUND

The purpose of this study was to address questions concerning the functional outcome following mandibular reconstruction with vascularized fibula flap in skeletally immature children

METHODS

Eleven patients 14 years old or younger who underwent mandibular reconstruction using a free fibula flap were evaluated.

RESULTS

The mean follow-up was 3.4 years. One flap loss occurred and required a second fibula flap. Panorex radiographs showed good bone union and growth in all patients. Functional outcomes were normal according to age in all patients. Two patients had long-term malocclusion. No patients had to undergo corrective orthognathic surgery. Donor-site morbidities consisted of great toe flexion contracture (n = 4) and a valgus deformity (n = 1). All patients had a normal gait, and there were no discrepancies in leg length.

CONCLUSION

A mandible reconstructed using a vascularized fibula flap appears to grow accordingly as the child grows, with minimal disturbance to the growth pattern of the midface.

Modulation of Notch signaling by antibodies specific for the extracellular negative regulatory region of NOTCH3

The Notch pathway regulates the development of many tissues and cell types and is involved in a variety of human diseases, making it an attractive potential therapeutic target. This promise has been limited by the absence of potent inhibitors or agonists that are specific for individual human Notch receptors (NOTCH1-4). Using an unbiased functional screening, we identified monoclonal antibodies that specifically inhibit or induce activating proteolytic cleavages in NOTCH3. Remarkably, the most potent inhibitory and activating antibodies bind to overlapping epitopes within a juxtamembrane negative regulatory region that protects NOTCH3 from proteolysis and activation in its resting autoinhibited state. The inhibitory antibodies revert phenotypes conveyed on 293T cells by NOTCH3 signaling, such as increased cellular proliferation, survival, and motility, whereas the activating antibody mimics some of the effects of ligand-induced Notch activation. These findings provide insights into the mechanisms of Notch autoinhibition and activation and pave the way for the further development of specific antibody-based modulators of the Notch receptors, which are likely to be of utility in a wide range of experimental and therapeutic settings.