Clinicopathologic predictors of distant metastasis in head and neck cancer

6086

Background: Despite advances in achieving improved locoregional control for patients with head and neck cancer (HNC), overall survival has not improved in the last 30 years. Several studies have implicated distant metastasis as a potential cause, hindering progress in the treatment of HNC. However, little is known about which patients fail systemically. We therefore sought to identify clinico-pathological factors that are associated with distant metastasis as the only cite of failure. Methods: We retrospectively studied 389 patients with head neck squamous cell carcinomas with distant metastases as the primary site of failure excluding all patients with locoregional recurrence and those receiving chemotherapy at primary presentation. The median follow up period was 5.3 years. An estimate of the risk of DM and DM free survival by prognostic factors was calculated using multivariate analysis and Cox proportional modeling. Results: Overall, 11% (43/389) of the patients developed DM. With univariate analysis, site of the tumor arising within the laryngopharynx, T stage (T3–4), N stage>2, and metastasis to level IV were significantly associated with DM. However, using Cox proportional hazards regression modeling, two clinicopathologic variables, N classification >N2b and diminishing degree of histologic differenention, were found to be most significantly associated with the development of systemic, distant metastasis. For patients staged as N2b or N2c, there was a relative risk (RR) of 6.13 (95% CI: 2.61 - 14.38; p < 0.0001) for developing DM. For patients staged as N3, the RR was 8.23 (95% CI: 2.39 - 28.38; p < 0.001). For patients with poorly differently HNSCC, RR was 11.01 (95% CI: 1.42 - 85.15; p = 0.022) Conclusions: Recognizing patients at primary presentation with tumors with the highest risk for the development of DM might le us to selectively treat them aggressively with systemic therapy to eradicate the tumor, thus improving overall survival rates.

No significant financial relationships to disclose.

Expression of c-kit Protein and Mutational Status of the c-kit Gene in Osteosarcoma and Their Clinicopathological Significance

We examined c-kit protein expression and mutations of the c-kit gene in 40 human osteosarcoma samples to their relationship with clinicopathology and prognosis of the disease. The expression of c-kit protein was evaluated by immunohistochemistry and single-strand conformational polymorphism was performed to evaluate c-kit gene mutations in exons 11 and 17. Expression of c-kit protein occurred in 25 (62.5%) osteosarcoma samples. Patients with osteosarcomas with higher c-kit protein expression levels were significantly more likely to experience local disease recurrence and had a significantly lower survival time than patients with lower c-kit expression. We found no evidence of mutations in exons 11 or 17. This study suggests that c-kit protein expression might serve as a prognostic marker for osteosarcoma, however exons 11 and 17 might not be suitable targets for osteosarcoma treatments based on suppression of c-kit tyrosine kinase activity.

Drug delivery to the spinal cord tagged with nanowire enhances neuroprotective efficacy and functional recovery following trauma to the rat spinal cord

The possibility that drugs attached to innocuous nanowires enhance their delivery within the central nervous system (CNS) and thereby increase their therapeutic efficacy was examined in a rat model of spinal cord injury (SCI). Three compounds--AP173 (SCI-1), AP713 (SCI-2), and AP364 (SCI-5) (Acure Pharma, Uppsala, Sweden)--were tagged with TiO(2)-based nanowires using standard procedure. Normal compounds were used for comparison. SCI was produced by making a longitudinal incision into the right dorsal horn of the T10-T11 segments under Equithesin anesthesia. The compounds, either alone or tagged with nanowires, were applied topically within 5 to 10 min after SCI. In these rats, behavioral outcome, blood-spinal cord barrier (BSCB) permeability, edema formation, and cell injury were examined at 5 h after injury. Topical application of normal compounds in high quantity (10 microg in 20 microL) attenuated behavioral dysfunction (3 h after trauma), edema formation, and cell injury, as well as reducing BSCB permeability to Evans blue albumin and (131)I. These beneficial effects are most pronounced with AP713 (SCI-2) treatment. Interestingly, when these compounds were administered in identical conditions after tagging with nanowires, their beneficial effects on functional recovery and spinal cord pathology were further enhanced. However, topical administration of nanowires alone did not influence trauma-induced spinal cord pathology or motor functions. Taken together, our results, probably for the first time, indicate that drug delivery and therapeutic efficacy are enhanced when the compounds are administered with nanowires.

Detection and localization of naturally transmitted avian leukosis subgroup J virus in egg-type chickens by in situ PCR hybridization

Avian leukosis virus (ALV) subgroup J (ALV-J) is an exogenous ALV and causes myeloid leukosis in meat-type chickens. We have previously reported the isolation and identification of ALV-J in commercial layer flocks from 12 farms in northern China. In this report, we further characterized this virus by in situ polymerase chain reaction (PCR) hybridization in various affected organs of chickens from six of the 12 farms. A routine method for hybridization of nucleic acid uses radioactive probe, such as a P32-labelled probe. We found that the non-radioactive digoxigenin (DIG) probe is sensitive enough to detect the nucleic acid of virus in chicken tissues. We used a pair of published primers (H5/H7) specific to the gp85 envelope gene and 3' region of pol gene of prototype ALV-J strain HPRS-103. The total RNA extracted from tumour, bone marrow, oviduct, liver and spleen of the diseased chickens from six commercial flocks, and cDNA was successfully amplified. Using the primers and cDNA, we obtained an ALV-J-specific cDNA probe of 545 bp in length by PCR. In situ PCR with H5/H7 primers was carried out in the paraffin sections from tissues of the diseased chickens, followed by in situ hybridization using the DIG-labelled cDNA probe. Positive hybridization signals were detected in the cytoplasm of paraffin sections of tumours and other organ tissues. The intensity of the signals was documented using an image analysis system measuring integral optical density (IOD). The IOD values for tissue sections treated by in situ PCR hybridization are significantly higher than that by in situ hybridization alone (P < 0.01). These data taken together suggest that in situ PCR hybridization is a more sensitive technique for detection of ALV-J in tissue sections.

Configurational and conformational classification of pyranose sugars

Automated cluster analysis is used to examine the conformation and configuration of pyranose sugars. Previous findings on this issue are confirmed, importantly from an analysis that requires no prior knowledge of the significant factors determining the conformational classification. The findings on the conformations adopted in the crystalline solid state are found to be different to existing quantum chemical calculations performed for D-glucose in the gas phase, but consistent with empirically determined conformations in the solution state. The use of this clustering analysis in studying chirality in the determined structures is discussed, as is the ability of this type of method to examine higher dimensions within the metric multi-dimensional scaling formalism.

Supporting evidence for reverse cochlear traveling waves

As a result of the cochlea's nonlinear mechanics, stimulation by two tones results in the generation of distortion products (DPs) at frequencies flanking the primary tones. DPs are measurable in the ear canal as oto-acoustic emissions, and are used to noninvasively explore cochlear mechanics and diagnose hearing loss. Theories of DP emissions generally include both forward and reverse cochlear traveling waves. However, a recent experiment failed to detect the reverse-traveling wave and concluded that the dominant emission path was directly through the fluid as a compression pressure [Ren, 2004, Nat. Neurosc.7, 333-334]. To explore this further, we measured intracochlear DPs simultaneously with emissions over a wide frequency range, both close to and remote from the basilar membrane. Our results support the existence of the reverse-traveling wave: (1) They show spatial variation in DPs that is at odds with a compression pressure. (2) Although they confirm a forward-traveling character of intraocochlear DPs in a broad frequency region of the best frequency, this behavior does not refute the existence of reverse-traveling waves. (3) Finally, the results show that, in cases in which it can be expected, the DP emission is delayed relative to the DP in a way that supports reverse-traveling-wave theory.

Systems biology of the neurospora biological clock

A major challenge of systems biology is explaining complex traits, such as the biological clock, in terms of the kinetics of macromolecules. The clock poses at least four challenges for systems biology: (i) identifying the genetic network to explain the clock mechanism quantitatively; (ii) specifying the clock's functional connection to a thousand or more genes and their products in the genome; (iii) explaining the clock's response to light and other environmental cues; and (iv) explaining how the clock's genetic network evolves. Here, the authors illustrate an approach to these problems by fitting an ensemble of genetic networks to microarray data derived from oligonucleotide arrays with approximately all 11 000 Neurospora crassa genes represented. A promising genetic network for the clock mechanism is identified.