Alok Thakar

iTRAQ-multidimensional liquid chromatography and tandem mass spectrometry-based identification of potential biomarkers of oral epithelial dysplasia and novel networks between inflammation and premalignancy.

Chronic exposure of the oral mucosa to carcinogens in tobacco is linked to inflammation and development of oral premalignant lesions (OPLs) with high risk of progression to cancer; there is currently no clinical methodology to identify high-risk lesions. We hypothesized that identification of differentially expressed proteins in OPLs in relation to normal oral tissues using proteomic approach will reveal changes in multiple cellular pathways and aid in biomarker discovery. Isobaric mass tags (iTRAQ)-labeled oral dysplasias and normal tissues were compared against pooled normal control by online liquid chromatography and tandem mass spectrometry. Verification of biomarkers was carried out in an independent set of samples by immunohistochemistry, immunoblotting, and RT-PCR. We identified 459 nonredundant proteins in OPLs, including structural proteins, signaling components, enzymes, receptors, transcription factors, and chaperones. A panel of three best-performing biomarkers identified by iTRAQ analysis and verified by immunohistochemistrystratifin (SFN), YWHAZ, and hnRNPKachieved a sensitivity of 0.83, 0.91, specificity of 0.74, 0.95, and predictive value of 0.87 and 0.96, respectively, in discriminating dysplasias from normal tissues, thereby confirming their utility as potential OPL biomarkers. Pathway analysis revealed direct interactions between all the three biomarkers and their involvement in two major networks involved in inflammation, signaling, proliferation, regulation of gene expression, and cancer. In conclusion, our work on determining the OPL proteome unraveled novel networks linking inflammation and development of epithelial dysplasia and their key regulatory proteins may serve as novel chemopreventive/therapeutic targets for early intervention. Additionally, we identified and verified a panel of OPL biomarkers that hold promise for large-scale validation for ultimate clinical use.

Heterogeneous ribonucleoprotein K is a marker of oral leukoplakia and correlates with poor prognosis of squamous cell carcinoma

Oral leukoplakia is a heterogeneous lesion with risk of cancer development; there are no biomarkers to predict its potential of malignant transformation. Tissue proteomic analysis of oral leukoplakia using iTRAQ labeling liquid chromatography–mass spectrometry showed overexpression of heterogeneous ribonucleoprotein K (hnRNP K), a transformation‐related RNA‐binding protein, in leukoplakia in comparison with normal tissue. Herein, we investigated the clinical significance of hnRNP K in identification of oral leukoplakic lesions in early stages and as a prognostic marker in head‐and‐neck/oral squamous cell carcinomas (HNOSCCs). Immunohistochemical analysis of hnRNP K was performed in 100 HNOSCCs, 199 leukoplakias and 55 nonmalignant tissues and correlated with clinicopathologic parameters and disease prognosis over 6 years for HNOSCCs. hnRNP K nuclear expression increased from normal tissues to leukoplakia, and frank malignancy (p < 0.001). Cytoplasmic hnRNP K increased significantly from leukoplakia to HNOSCCs (p < 0.001) and was associated with poor prognosis of HNOSCCs (p = 0.011) by Kaplan–Meier analysis. The most important finding of our follow‐up study is that cytoplasmic hnRNP K is an independent predictor of disease recurrence in HNOSCC patients. In conclusion, nuclear hnRNP K may serve as a potential marker for early diagnosis, whereas its cytoplasmic accumulation can help to identify a subgroup of HNOSCC patients with poor prognosis, suggesting its putative utility in clinical management of HNOSCC.

Delayed Optic Nerve Decompression for Indirect Optic Nerve Injury

Objective To test the efficacy of delayed optic nerve decompression in traumatic optic nerve injury.

Vertigo syndromes and mechanisms in migraine

This paper attempts to define and categorize the vertigo associated with migraine. A retrospective chart review of 344 cases of vertigo identified 19 cases with headaches characteristic of migraine as per strictly defined criteria (International Headache Society, 1988). Four distinct types of vertiginous syndromes were noted. The commonest syndrome (Group I) manifested transient episodes of imbalance with additional momentary subjective rotary vertigo worsened by movement. The attacks lasted a few hours and evaluation in the inter-episode interval demonstrated no vestibular deficit. Group II manifested transient objective rotatory vertigo of from 10 minutes to a few hours but no demonstrable permanent vestibular deficit. Group III displayed symptoms and signs characteristic of benign paroxysmal positional vertigo (BPPV) and Group IV manifested a permanent unilateral labyrinthine weakness. Causation of vertigo by migraine was implied in 10 of 19 cases where the headache and vertigo occurred simultaneously and in two other cases where the vertigo improved with anti-migraine prophylactic treatment. Four distinct and characteristic vertigo syndromes have been noted with migraine. Their spectrum ranges from a transient reversible dysfunction to a more permanent destruction, and includes involvement of both the peripheral and the central vestibular systems.

Nuclear S100A7 Is Associated with Poor Prognosis in Head and Neck Cancer

Background Tissue proteomic analysis of head and neck squamous cell carcinoma (HNSCC) and normal oral mucosa using iTRAQ (isobaric tag for relative and absolute quantitation) labeling and liquid chromatography-mass spectrometry, led to the identification of a panel of biomarkers including S100A7. In the multi-step process of head and neck tumorigenesis, the presence of dysplastic areas in the epithelium is proposed to be associated with a likely progression to cancer; however there are no established biomarkers to predict their potential of malignant transformation. This study aimed to determine the clinical significance of S100A7 overexpression in HNSCC. Methodology Immunohistochemical analysis of S100A7 expression in HNSCC (100 cases), oral lesions (166 cases) and 100 histologically normal tissues was carried out and correlated with clinicopathological parameters and disease prognosis over 7 years for HNSCC patients. Overexpression of S100A7 protein was significant in oral lesions (squamous cell hyperplasia/dysplasia) and sustained in HNSCC in comparison with oral normal mucosa (ptrend<0.001). Significant increase in nuclear S100A7 was observed in HNSCC as compared to dysplastic lesions (p = 0.005) and associated with well differentiated squamous cell carcinoma (p = 0.031). Notably, nuclear accumulation of S100A7 also emerged as an independent predictor of reduced disease free survival (p = 0.006, Hazard ratio (HR = 7.6), 95% CI = 1.3−5.1) in multivariate analysis underscoring its relevance as a poor prognosticator of HNSCC patients. Conclusions Our study demonstrated nuclear accumulation of S100A7 may serve as predictor of poor prognosis in HNSCC patients. Further, increased nuclear accumulation of S100A7 in HNSCC as compared to dysplastic lesions warrants a large-scale longitudinal study of patients with dysplasia to evaluate its potential as a determinant of increased risk of transformation of oral premalignant lesions.

SIGNIFICANCE OF PROMOTER HYPERMETHYLATION OF p16 GENE FOR MARGIN ASSESSMENT IN CARCINOMA TONGUE

Loss of p16 expression by promoter hypermethylation has been reported as an early event in the development of oral cancer. The aim of our study was to explore the prognostic implications of presence of promoter hypermethylation of p16 gene in surgical margins in carcinoma tongue.

68Ga-DOTANOC PET/CT for Baseline Evaluation of Patients with Head and Neck Paraganglioma

The purpose of this study was to evaluate the role of 68Ga-labeled DOTANOC PET/CT for baseline evaluation of patients with head and neck paragangliomas (HNPs). Methods: The data for 26 patients (mean age ± SD, 34.3 ± 10.4 y; 50% men) with known or suspected HNPs who underwent 68Ga-DOTANOC PET/CT for staging were retrospectively analyzed. PET/CT was performed after intravenous injection of 132–222 MBq of 68Ga-DOTANOC. The images were evaluated by 2 experienced nuclear medicine physicians in consensus, both qualitatively and quantitatively. The PET/CT findings were grouped as HNPs, paraganglioma at other sites (non-HNPs), and metastatic disease. The size and maximum standardized uptake values (SUVmax) were measured for all lesions. All of the patients also underwent whole-body 131I-metaiodobenzylgunanidine (131I-MIBG) scintigraphy and conventional imaging (CT/MR imaging) of the head and neck region. Their results were compared with those of 68Ga-DOTANOC PET/CT. Results: 68Ga-DOTANOC PET/CT findings were positive in all 26 patients, and 78 lesions were detected. PET/CT imaging demonstrated 45 HNPS, 10 non-HNPs, and 23 metastatic sites. Fifteen patients (57.6%) had more than one site of disease on PET/CT. Among 45 HNPs, 26 were carotid body tumors (CBTs), 15 glomus jugulare, 3 glomus tympanicum, and 1 laryngeal paraganglioma. A positive correlation was seen between size and SUVmax of HNPs (ρ = 0.323; P = 0.030). The SUVmax of the CBTs was higher than that of jugulotympanic paragangliomas (P = 0.026). No correlation was seen between size and SUVmax (ρ = 0.069; P = 0.854) of non-HNPs. The size and SUVmax of non-HNPs were significantly less than those of HNPs (P = 0.029 and 0.047, respectively). 131I-MIBG scintigraphy showed only 30 of the 78 lesions and was inferior to PET/CT (P < 0.0001). Conventional imaging (CT/MR imaging) was positive for 42 of 49 head and neck lesions and was inferior to PET/CT on direct comparison (P = 0.015). A combination of CT/MR imaging and 131I-MIBG scintigraphy detected only 53 of 78 (67.9%) lesions and was also inferior to PET/CT (P < 0.0001). Conclusion: 68Ga-DOTANOC PET/CT is useful for the baseline evaluation of patients with HNPs and can demonstrate synchronous paragangliomas at other sites and distant metastases. It is superior to 131I-MIBG scintigraphy and conventional imaging (CT/MR imaging) for this purpose.

Concomitant chemoradiation versus radical radiotherapy in advanced squamous cell carcinoma of oropharynx and nasopharynx using weekly cisplatin: a phase II randomized trial

BACKGROUND To know the effectiveness and tolerance of weekly cisplatin added to radiotherapy (RT) in advanced carcinoma of oropharynx and nasopharynx. PATIENTS AND METHODS Stage II-IV cancer patients were randomly assigned to either radical RT, 70 Gy/35 fractions over 7 weeks (RT arm), or chemoradiotherapy (CRT), cisplatin 40 mg/m² weekly for seven doses plus RT. Primary end points were (i) the responses, (ii) toxicity profile, and (iii) overall survival (OS) in two groups. Study period was from June 2003 to July 2005. RESULTS One hundred and fifty-three patients were randomly allocated to the study, 76 in RT arm and 77 in CRT arm. Seventy-one in each arm completed the planned treatment; complete response (CR): 67.1% versus 80.5% in RT and CRT arms (P = 0.04). Grade III and IV toxicity were 16% and 40% in RT and CRT arms, respectively (P = 0.01). There were frequent treatment interruptions (9.3% versus 28.9%; P = 0.003) and hospitalization (20% versus 40.8%) in the CRT group. OS was superior in the CRT arm (P = 0.02): 27 months [95% confidence interval (CI) 15.2-36.8] for RT versus not reached for CRT. Three-year OS was 42% for RT and 62% for CRT group. CRT and CR were independent prognostic factors. CONCLUSION This trial on Indian head and neck squamous cell carcinoma patients confirms that the use of weekly cisplatin is safe and CRT is superior to RT alone resulting in higher OS.

Allergic fungal sinusitis: expanding the clinicopathologic spectrum.

OBJECTIVE: We sought to determine whether histologic tissue invasion occurs in allergic fungal sinusitis (AFS) and, if so, to identify clinical indicators for the same. STUDY DESIGN AND SETTING: We conducted a retrospective case record review of all 28 AFS cases identified by histology over a 32-month period at a tertiary care referral center. All histologic specimens were reevaluated for features of invasive pathology, and case records were correlated for clinical, radiologic, or laboratory parameters associated with such invasion. RESULTS: In addition to the universal finding of the characteristic allergic mucin with fungal elements on histopathologic examination of the sinus luminal contents, 6 cases (21%) had additional evidence of mucosal invasion as indicated by granulomatous inflammation and branching septate fungal hyphae in the submucosal tissues. Such coexistent invasion was associated with advanced disease as indicated by a higher incidence of orbital involvement on clinical evaluation (P = 0.024), and extra-sinus spread (intraorbital or intracranial spread) on the computed tomography evaluation (P = 0.003). The single death that occurred on follow-up was in a patient with coexistent invasion. CONCLUSION: Advanced AFS may be complicated by histologic evidence of tissue invasion. SIGNIFICANCE: The noninvasive and invasive forms of fungal sinusitis are not necessarily discrete and may coexist in the same patient. Clinical features of orbital involvement or computed tomography manifestations of extrasinus spread should alert the clinician to the possibility of invasion.

Improving outcomes in rhinocerebral mucormycosis - early diagnostic pointers and prognostic factors

Rhinocerebral mucormycosis is an uncommon, rapidly progressive, highly fatal sinus infection, usually occurring in immunocompromised hosts. We describe our clinical experience with nine such consecutive cases managed at our centre, with emphasis on identifying early diagnostic and prognostic features. Perinasal cellulitis/paraesthesia was the most frequent early clinical sign of disease, being evident in at least six cases. Periorbital oedema, mucopurulent rhinorrhoea and nasal crusting were the other early manifestations. Concurrent computed tomography (CT) scan at this initial stage however revealed only minimal mucosal thickening of the sinuses in all four cases wherein it was done. Intracranial extension as evident on CT was the only adverse prognostic sign (p<0.05). The present report highlights the importance of early diagnosis and prompt institution of antifungal chemotherapy in ensuring a favourable outcome in rhinocerebral mucormycosis. However, initial CT is frequently near-normal and biopsy time-consuming and often not feasible. To optimize early diagnosis therefore, the clinician should be highly alert to certain subtle clinical signs, in the appropriate setting of an immunocompromised patient.