Synthesis and biological evaluation of panitumumab-IRDye800 conjugate as a fluorescence imaging probe for EGFR-expressing cancers

To investigate panitumumab-IRDye800 as an intraoperative optical imaging agent for epidermal growth factor receptor (EGFR)-expressing cancers, we developed clinical-quality panitumumab-IRDye800 and evaluated its specificity and sensitivity to visualize tumors by fluorescence imaging in a variety of mouse xenograft models with different levels of EGFR-expression. Panitumumab was chemically conjugated to NIR-dye (Li-COR 800CW) at well-defined and limited substitution ratio (1:1-2) for the characterization of fluorescence signals. Yield and purity of the conjugate was 80±5% and 95±2% respectively (n= 6). Quality control (QC) tests showed that product was suitable for clinical development. Female athymic nude xenograft tumor bearing mice (n=5 per tumor model) with very low (BT-474), moderate (MDA-MB-231), and high (MDA-MB-468) EGFR-expression levels were administered panitumumab-IRDye800 formulations (100 μg of mAb in 100 μL of 0.9% saline) via tail-vein injection. Animal imaging and biodistribution experiments were conducted on the FMT 2500 (Perkin Elmer) fluorescence scanner at 24, 48, 72, 96, and 144 hours post injection. Immuno-fluorescence images of panitumumab-IRDye conjugate recorded in mouse xenograft models showed a good correlation (R2 = 0.91) between EGFR-expression level and tumor uptake. Uptake of panitumumab labeled with IR-Dye or [89Zr] in different tumor xenografts with high, medium, and low EGFR expression, as measured by fluorescence or radioactive counts are highly correlated (r2= 0.99). This preclinical in-vivo study proved that panitumumab-IRDye800 is specific and optical imaging in conjunction with this probe is sensitive enough to detect EGFR-expressing tumors.

Correlation of echocardiographic and angiographic measurements of the pulmonary valve annulus in pulmonary stenosis

OBJECTIVES

The pulmonary valve (PV) annulus is routinely measured angiographically in PV stenosis prior to balloon dilation. We sought to establish whether this radiation exposure is justified, or whether echocardiographic measurements prior to the procedure are sufficient to guide balloon selection.

BACKGROUND

Previous studies have found a strong correlation between echocardiographic and angiographic measurements of the PV annulus. However, error of measurement and its implication for procedural practice has not been explored.

METHODS

A total of 90 procedures in 84 patients were analyzed, at a median age 7.6 months (range 1 day to 14.2 years). The contemporaneous echocardiographic and angiographic measurements were recorded, and the original echocardiograms were re-measured in the 72 available cases by two independent reviewers.

RESULTS

There was a good correlation between the two measurement methods (R(2)  = 0.87). However, the echocardiographic PV measurements were smaller on average, with a significant variation in that discrepancy (mean ratio 0.941 (±0.16)). There was no significant reduction in error if extreme measurements (PV annulus z-score <-3) were excluded (P = 0.09), or if the reviewed echocardiographic measurements were used (P = 0.58).

CONCLUSIONS

There is an unacceptable discrepancy between the measurement techniques: 95% of patients are predicted to have an echocardiographic measurement error between -37% and +26%. Therefore, there is no correction factor that could be employed to allow safe selection of balloon size, and balloon pulmonary valvoplasty without angiographic PV measurement cannot be advocated.

Co-existence of clonal expanded autologous and transplacental-acquired maternal T cells in recombination activating gene-deficient severe combined immunodeficiency

It is commonly accepted that the presence of high amounts of maternal T cells excludes Omenn syndrome (OS) in severe combined immunodeficiency (SCID). We report a SCID patient with a novel mutation in the recombination activating gene (RAG)1 gene (4-BP DEL.1406 TTGC) who presented with immunodeficiency and OS. Several assays, including representatives of specific T cell receptors (TCR), Vβ families and TCR-γ rearrangements, were performed in order to understand more clearly the nature and origin of the patient's T cells. The patient had oligoclonal T cells which, based on the patient-mother human leucocyte antigen (HLA)-B50 mismatch, were either autologous or of maternal origin. These cell populations were different in their numbers of regulatory T cells (T(reg)) and the diversity of TCR repertoires. This is the first description of the co-existence of large amounts of clonal expanded autologous and transplacental-acquired maternal T cells in RAG1-deficient SCID.

Ultrasound-stimulated drug delivery for treatment of residual disease after incomplete resection of head and neck cancer

Microbubbles triggered with localized ultrasound (US) can improve tumor drug delivery and retention. Termed US-stimulated drug delivery, this strategy was applied to head and neck cancer (HNC) in a post-surgical tumor resection model. Luciferase-positive HNC squamous cell carcinoma (SCC) was implanted in the flanks of nude athymic mice (N = 24) that underwent various degrees of surgical tumor resection (0%, 50% or 100%). After surgery, animals received adjuvant therapy with cetuximab-IRDye alone, or cetuximab-IRDye in combination with US-stimulated drug delivery or saline injections (control) on days 4, 7 and 10. Tumor drug delivery was assessed on days 0, 4, 7, 10, 14 and 17 with an in vivo fluorescence imaging system, and tumor viability was evaluated at the same times with in vivo bioluminescence imaging. Tumor caliper measurements occurred two times per week for 24 d. Optical imaging revealed that in the 50% tumor resection group, US-stimulated drug delivery resulted in a significant increase in cetuximab delivery compared with administration of drug alone on day 10 (day of peak fluorescence) (p = 0.03). Tumor viability decreased in all groups that received cetuximab-IRDye in combination with US-stimulated drug delivery, compared with the group that received only the drug. After various degrees of surgical resection, this novel study reports positive improvements in drug uptake in the residual cancer cells when drug delivery is stimulated with US.

Impact of pharyngeal closure technique on fistula after salvage laryngectomy

IMPORTANCE

No consensus exists as to the best technique, or techniques, to optimize wound healing, decrease pharyngocutaneous fistula formation, and shorten both hospital length of stay and time to initiation of oral intake after salvage laryngectomy. We sought to combine the recent experience of multiple high-volume institutions, with different reconstructive preferences, in the management of pharyngeal closure technique for post-radiation therapy salvage total laryngectomy in an effort to bring clarity to this clinical challenge.

OBJECTIVE

To determine if the use of vascularized flaps in either an onlay or interposed fashion reduces the incidence or duration of pharyngocutaneous fistula after salvage laryngectomy compared with simple primary closure of the pharynx.

DESIGN

Multi-institutional retrospective review of all patients undergoing total laryngectomy after having received definitive radiation therapy with or without chemotherapy between January 2005 and January 2012, conducted at 7 academic medical centers.

SETTING

Academic, tertiary referral centers.

PATIENTS

The study population comprised 359 patients from 8 institutions. All patients had a history of laryngeal irradiation and underwent laryngectomy between 2005 and 2012. They were grouped as primary closure, pectoralis myofascial onlay flap, or interposed free tissue. All patients had a minimum of 4 months follow-up.

MAIN OUTCOMES AND MEASURES

Fistula incidence, severity, and predictors of fistula.

RESULTS

Of the 359 patients, fistula occurred in 94 (27%). For patients with fistula, hospital stay increased from 8.9 to 12.1 days (P < .001) and oral diet initiation was delayed from 10.5 days to 29.9 days (P < .001). Patients were grouped according to closure technique: primary closure (n = 99), pectoralis onlay flap (n = 40), and interposed free tissue (n = 220). Incidence of fistula with primary closure was 34%. For the interposed free flap group, the fistula rate was lower at 25% (P = .07). Incidence of fistula was the lowest for the pectoralis onlay group at 15% (P = .02). Multivariate analysis confirmed a significantly lower fistula rate with either flap technique. For patients who developed fistula, mean duration of fistula was significantly prolonged with primary closure (14.0 weeks) compared with pectoralis flap (9.0 weeks) and free flap (6.5 weeks).

CONCLUSIONS AND RELEVANCE

Pharyngocutaneous fistula remains a significant problem following salvage laryngectomy. Use of nonirradiated, vascularized flaps reduced the incidence and duration of fistula and should be considered during salvage laryngectomy.

A comprehensive laboratory-based program for classification of variants of uncertain significance in hereditary cancer genes

Genetic testing has the potential to guide the prevention and treatment of disease in a variety of settings, and recent technical advances have greatly increased our ability to acquire large amounts of genetic data. The interpretation of this data remains challenging, as the clinical significance of genetic variation detected in the laboratory is not always clear. Although regulatory agencies and professional societies provide some guidance regarding the classification, reporting, and long-term follow-up of variants, few protocols for the implementation of these guidelines have been described. Because the primary aim of clinical testing is to provide results to inform medical management, a variant classification program that offers timely, accurate, confident and cost-effective interpretation of variants should be an integral component of the laboratory process. Here we describe the components of our laboratory's current variant classification program (VCP), based on 20 years of experience and over one million samples tested, using the BRCA1/2 genes as a model. Our VCP has lowered the percentage of tests in which one or more BRCA1/2 variants of uncertain significance (VUSs) are detected to 2.1% in the absence of a pathogenic mutation, demonstrating how the coordinated application of resources toward classification and reclassification significantly impacts the clinical utility of testing.

Salvage surgery for recurrent cancers of the oropharynx: comparing TORS with standard open surgical approaches

IMPORTANCE

Surgical salvage may be the only viable treatment option for recurrent tumors of the oropharynx. To our knowledge, there have been no published reports directly comparing the oncologic and functional outcomes of patients with recurrent oropharyngeal squamous cell carcinoma (SCC) treated with transoral robotic-assisted surgery (TORS) with those treated with traditional open surgical approaches.

OBJECTIVE

To compare the oncologic and functional outcomes of patients with recurrent oropharyngeal SCC treated with TORS with those treated with traditional open surgical approaches.

DESIGN

Retrospective multi-institutional case-control study; study dates, March 2003 through October 2011.

SETTING

Four tertiary care institutions (University of Alabama at Birmingham; M. D. Anderson Cancer Center, Houston, Texas; Mayo Clinic, Rochester, Minnesota; and Henry Ford Hospital, Detroit, Michigan). PARTICIPANTS Sixty-four patients who underwent salvage TORS for recurrent oropharyngeal SCC were matched by TNM stage to 64 patients who underwent open salvage resection. INTERVENTION OR EXPOSURE: Salvage TORS for recurrent SCC of the oropharynx.

MAIN OUTCOME AND MEASURES

Patient demographics, operative data, functional, and oncologic outcomes were recorded and compared with a similarly TNM-matched patient group that underwent salvage surgical resection by traditional open surgical approaches. RESULTS Patients treated with TORS were found to have a significantly lower incidence of tracheostomy use (n = 14 vs n = 50; P < .001), feeding tube use (n = 23 vs n = 48; P < .001), shorter overall hospital stays (3.8 days vs 8.0 days; P < .001), decreased operative time (111 minutes vs 350 minutes; P < .001), less blood loss (49 mL vs 331 mL; P < .001), and significantly decreased incidence of positive margins (n = 6 vs n = 19; P = .007). The 2-year recurrence-free survival rate was significantly higher in the TORS group than in the open approach group (74% and 43%, respectively) (P = .01).

CONCLUSIONS AND RELEVANCE

This study demonstrates that TORS offers an alternative surgical approach to recurrent tumors of the oropharynx with acceptable oncologic outcomes and better functional outcomes than traditional open surgical approaches. This adds to the growing amount of clinical evidence to support the use of TORS in selected patients with recurrent oropharyngeal SCC as a feasible and oncologically sound method of treatment.

A century of leishmaniasis in Alpes-Maritimes, France

A century of publications on leishmaniasis in Alpes-Maritimes, in southern France, is here reviewed. Autochtonous human and canine leishmaniasis were first recognised in this département, which lies by the Mediterranean Sea and near the Italian border, in 1918 and 1925, respectively. The parasite responsible for the leishmaniasis, Leishmania infantum, is transmitted by Phlebotomus perniciosus and P. ariasi. The human leishmaniasis is zoonotic, with domestic dogs acting as the main 'reservoir' hosts. In prospective surveys over the last two decades, a mean of 12% of the domestic dogs checked in Alpes-Maritimes have been found seropositive for L. infantum but only about 50% of the seropositive animals showed any clinical signs of infection at the time of the surveys. During the last 30 years, 178 cases of human visceral leishmaniasis have been recorded in the area. Such cases are sporadic and often opportunistic, occurring predominantly in children (29% of the 178 cases) or HIV-positive subjects (31%). Recently, it has been demonstrated that, in Alpes-Maritimes, approximately 20% of those found seropositive in leishmanin skin tests are asymptomatic carriers, with amastigotes in their peripheral blood.

Preexposure prophylaxis (PrEP) of HIV infection in France: a nationwide cross-sectional study (PREVIC study)

Although preliminary studies showed that preexposure prophylaxis (PrEP) lowers the HIV transmission in individuals with HIV, confirmative trials are ongoing and PrEP is not routinely recommended. The aim of this study was to assess whether individuals with HIV share antiretroviral (ARV) drugs for PrEP and to describe awareness and discussion on PrEP in this population. A cross-sectional survey was conducted in France in 23 representative departments of infectious diseases and internal medicine. Physicians administered an anonymous standardized questionnaire to all individuals with HIV receiving ARVs and followed between 24 and 31 October 2011. The questionnaire included items regarding PrEP (awareness; discussion with their close circle, physician or patients' association; experience), personal sociodemographic characteristics, risk behaviors and HIV status of the participants. Five hundred and ninety three participants were recruited: male 74.2% (men who have sex with men 52.4%, heterosexuals 21.6%), member of patient's association 9.8%. Half of them (50.6%) lived with a stable partner and 35.2% with an HIV-negative partner. Almost half (41.8%) were aware and 29.5% had had discussion about PrEP. In logistic regression, awareness and discussion on PrEP were more frequent: (1) among males, in patients' association members (p< 0.001 for both) and in nonheterosexuals (p=0.023 and 0.057, respectively); (2) among women, in those not living with a stable partner (p=0.035 and p=0.03, respectively) or living with an HIV-negative partner (p=0.049 and p=0.083, respectively). One percent of the participants declared having shared ARVs with someone and 8.3% reported PrEP in their close circle. Men reporting PrEP in their close circle shared ARVs more frequently than those who did not (10.3% vs. 0.2%, p < 0.001). Today, individuals with HIV do not seem to widely share personal ARVs for PrEP with seronegative people. A significant number of individuals with HIV are aware of and commonly discuss PrEP.

Optical fluorescent imaging to monitor temporal effects of microbubble-mediated ultrasound therapy

Microbubble-mediated ultrasound therapy can noninvasively enhance drug delivery to localized regions in the body. This technique can be beneficial in cancer therapy, but currently there are limitations to tracking the therapeutic effects. The purpose of this experiment was to investigate the potential of fluorescent imaging for monitoring the temporal effects of microbubble-mediated ultrasound therapy. Mice were implanted with 2LMP breast cancer cells. The animals underwent microbubble-mediated ultrasound therapy in the presence of Cy5.5 fluorescent-labeled IgG antibody (large molecule) or Cy5.5 dye (small molecule) and microbubble contrast agents. Control animals were administered fluorescent molecules only. Animals were transiently imaged in vivo at 1, 10, 30, and 60 min post therapy using a small animal optical imaging system. Tumors were excised and analyzed ex vivo. Tumors were homogenized and emulsion imaged for Cy5.5 fluorescence. Monitoring in vivo results showed significant influx of dye into the tumor (p < 0.05) using the small molecule, but not in the large molecule group (p > 0.05). However, after tumor emulsion, significantly higher dye concentration was detected in therapy group tumors for both small and large molecule groups in comparison to their control counterparts (p <0.01). This paper explores a noninvasive optical imaging method for monitoring the effects of microbubble-mediated ultrasound therapy in a cancer model. It provides temporal information following the process of increasing extravasation of molecules into target tumors.

Validation of the risk model: high-risk classification and tumor pattern of invasion predict outcome for patients with low-stage oral cavity squamous cell carcinoma

The risk model is a validated outcome predictor for patients with head and neck squamous cell carcinoma (Brandwein-Gensler et al. in Am j surg pathol 20:167-178, 2005; Am J Surg Pathol 34:676-688, 2010). This model may potentially shift treatment paradigms for patients with low-stage cancers, as current protocols dictate that they might receive only primary surgery. Here we test the hypothesis that the Risk Model has added prognostic value for low-stage oral cavity squamous cell carcinoma (OCSCC) patients. 299 patients with Stage I/II OCSCC were characterized according to the risk model (Brandwein-Gensler et al. in Am J Surg Pathol 20:167-178, 2005; Am J Surg Pathol 34:676-688, 2010). Cumulative incidence and competing risk analysis were performed for locoregional recurrence (LRR) and disease-specific survival (DSS). Receiver operating characteristic analyses were performed for worst pattern of invasion (WPOI) and the risk categories. 292 patients were analyzed; 30 T1N0 patients (17%) and 26 T2N0 patients (23%) developed LRR. Disease-specific mortality occurred in 9 T1N0 patients (6%) and 9 T2N0 patients (10%). On multivariable analysis, the risk model was significantly predictive of LRR (p = 0.0012, HR 2.41, 95% CI 1.42, 4.11) and DSS (p = 0.0005, HR 9.16, 95% CI 2.65, 31.66) adjusted for potential confounders. WPOI alone was also significantly predictive for LRR adjusted for potential confounders with a cut-point of either WPOI-4 (p = 0.0029, HR 3.63, 95% CI 1.56, 8.47) or WPOI-5 (p = 0.0008, HR 2.55, 95% CI 1.48, 4.41) and for DSS (cut point WPOI-5, p = 0.0001, HR 6.34, 95% CI 2.50, 16.09). Given a WPOI-5, the probability of developing locoregional recurrence is 42%. Given a high-risk classification for a combination of features other than WPOI-5, the probability of developing locoregional recurrence is 32%. The Risk Model is the first validated model that is significantly predictive for the important niche group of low-stage OCSCC patients.