Conservation of genetic diversity hotspots of the high-valued relic yellowhorn (Xanthoceras sorbifolium) considering climate change predictions.

Genetic structure and major climate factors may contribute to the distribution of genetic diversity of a highly valued oil tree species Xanthoceras sorbifolium (yellowhorn). Long-term over utilization along with climate change is affecting the viability of yellowhorn wild populations. To preserve the species known and unknown valuable gene pools, the identification of genetic diversity "hotspots" is a prerequisite for their consideration as in situ conservation high priority. Chloroplast DNA (cpDNA) diversity was high among 38 natural populations (H d = 0.717, K = 4.616, Tajmas' D = -0.22) and characterized by high genetic divergence (F ST = 0.765) and relatively low gene flow (N m = 0.03), indicating populations isolation reflecting the species' habitat fragmentation and inbreeding depression. Six out of the studied 38 populations are defined as genetic diversity "hotspots." The number and geographic direction of cpDNA mutation steps supported the species southwest to northeast migration history. Climatic factors such as extreme minimum temperature over 30 years indicated that the identified genetic "hotspots" are expected to experience 5°C temperature increase in next following 50 years. The results identified vulnerable genetic diversity "hotspots" and provided fundamental information for the species' future conservation and breeding activities under the anticipated climate change. More specifically, the role of breeding as a component of a gene resource management strategy aimed at fulfilling both utilization and conservation goals.

Chi-Ju-Di-Huang-Wan protects rats against retinal ischemia by downregulating matrix metalloproteinase-9 and inhibiting p38 mitogen-activated protein kinase.

BACKGROUND: Retinal ischemia is a retinal disorder related to retinal vascular occlusion, glaucoma, diabetic retinopathy and age-related macular degeneration. The study aimed to evaluate the protective effects and underlying mechanisms of Chi-Ju-Di-Huang-Wan (CJDHW) against retinal ischemia in rats. METHODS: High intraocular pressure (HIOP)-induced retinal ischemia was established in Wistar rats by raising their intraocular pressure to 120 mmHg for 60 min with in an eye whose anterior chamber was cannulated with a 30-guage needle adapted to a normal saline bottle through an intravenous line. This ischemic insult was followed by 1 or 7 days of reperfusion. The effects of CJDHW were studied by (i) electroretinogram (ERG); (ii) real-time polymerase chain reaction to determine the retinal mRNA levels of Thy-1 and matrix metalloproteinase-9 (MMP-9); (iii) Western blot analysis to determine the retinal protein levels of B cell lymphoma 2 (Bcl-2), heme oxygenase-1 (HO-1), phosphorylated-p38 mitogen-activated protein kinase (P-p38 MAPK) and MMP-9; (iv) hematoxylin and eosin (HE) staining; (v) fluorogold retrograde labeling; and (vi) terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) apoptosis assay. Moreover, after fixation with 4 % paraformaldehyde and 30 % sucrose, the isolated retinas were sectioned and immunolabeled with goat anti-choline acetyltransferase (ChAT) polyclonal antibody, mouse anti-vimentin monoclonal antibody and rabbit anti-glial fibrillary acidic protein (GFAP) polyclonal antibody. The retinal sections were then incubated with rhodamine-conjugated rabbit anti-goat antibody, fluorescein isothiocyanate (FITC)-conjugated goat anti-mouse IgG or FITC-conjugated goat anti-rabbit IgG. A daily oral intake of 3 mL of water (vehicle; Group 2) or CJDHW (2.8 or 4.2 g/kg/day; CJDHW2.8 or CJDHW4.2; Group 3 or 4) was given for 7 consecutive days either before (preischemic drug administration) or after HIOP-induced retinal ischemic injury (postischemic drug administration). In Group 5, an intravitreal injection of 4 µL of 0.5 mM SB203580 (p38 MAPK inhibitor) was performed on the ischemic eye 15 min before retinal ischemia. The control rats received a sham procedure (Group 1) where the saline reservoir was not raised. RESULTS: The ischemia-induced changes (Group 2) were significantly modulated by pretreating the rats with 4.2 g/kg/day of CJDHW (Group 4; ERG: P < 0.001 on I/R day 7; HE stain: P < 0.001 on I/R day 7; TUNEL: P = 0.05 on I/R day 7; retrograde labeling: P = 0.007 on I/R day 7; Thy-1 mRNA: P = 0.02; MMP-9 mRNA: P < 0.001; Bcl-2 protein: P = 0.02; HO-1 protein: P = 0.03; P-p38 MAPK protein: P < 0.001; MMP-9 protein: P = 0.02). These modulations included the following features (Group 2 vs. 4), increased ERG b-wave amplitudes (0.38 ± 0.04 vs. 0.81 ± 0.03), increased inner retinal thickness (45.08 ± 2.85 vs. 67.98 ± 5.48 µm), increased ChAT immunolabeling, decreased vimentin/GFAP immunoreactivity, less numerous apoptotic cells in the ganglion cell layer (1.40 ± 0.55 vs. 0.60 ± 0.55), and more numerous retinal ganglion cells (887.73 ± 158.18 vs. 1389.02 ± 53.20). Moreover, increased Thy-1 (0.31 ± 0.15 vs. 0.78 ± 0.32) and decreased MMP-9 mRNA levels were found (4.44 ± 0.84 vs. 1.13 ± 0.34), respectively. Furthermore, the Bcl-2 protein level (0.78 ± 0.08 vs. 1.80 ± 0.34) was increased while the HO-1 (0.99 ± 0.20 vs. 4.15 ± 2.08), P-p38 MAPK (1.12 ± 0.18 vs. 0.57 ± 0.18) and MMP-9 levels were decreased (0.70 ± 0.23 vs. 0.39 ± 0.10). The ischemia-associated increases in P-p38 and MMP-9 protein levels were also attenuated by 0.5 mM SB203580 (P-p38 MAPK: 1.12 ± 0.18 vs. 0.18 ± 0.07, P < 0.001; MMP-9: 0.70 ± 0.23 vs. 0.21 ± 0.07, P = 0.002). This was also the case to the MMP_enzyme activity (Group 2 vs. 4: 5.03 ± 1.57 vs. 1.59 ± 0.47, P = 0.002; Group 2 vs. 5: 5.03 ± 1.57 vs. 1.35 ± 0.41, P = 0.001). CONCLUSION: Treatment of the rats suffering from retinal ischemia with CJDHW inhibited apoptosis, increased antioxidative activity, downregulated MMP-9 and inhibited p38 MAPK.

Niche and Neutral Processes Together Determine Diversity Loss in Response to Fertilization in an Alpine Meadow Community.

Fertilization via nutrient deposition and agricultural inputs is one of the most important factors driving decreases in plant diversity. However, we still do not fully understand which processes (niche process or neutral process) are more important in leading to decreases in plant diversity caused by fertilization. A hypothesis-based approach was used to test the relative importance of niche versus neutral processes along a fertilization gradient in an alpine meadow community on the eastern Tibetan plateau, China. Niche overlap values were calculated for species biomass, and the null model was used to generate the values of niche overlap expected at random. A linear regression modeling was used to evaluate the relationship between functional traits (specific leaf area, leaf dry matter content, and leaf total nitrogen concentration) and species relative abundance. Our results demonstrated that observed niche overlap for species biomass was significantly higher than expected at lower fertilization gradients. Moreover, we also found a significantly negative correlation between species relative abundance and specific leaf area and leaf dry matter content, but a significantly positive correlation between relative abundance and leaf nitrogen concentration at lower fertilization gradients. However, these relationships were not significant at higher fertilization gradients. We concluded that community assembly is dynamic progression along the environmental gradients, and niche and neutral processes may together determine species diversity loss in response to fertilization.

Plant Functional Diversity Can Be Independent of Species Diversity: Observations Based on the Impact of 4-Yrs of Nitrogen and Phosphorus Additions in an Alpine Meadow.

Past studies have widely documented the decrease in species diversity in response to addition of nutrients, however functional diversity is often independent from species diversity. In this study, we conducted a field experiment to examine the effect of nitrogen and phosphorus fertilization ((NH4)2 HPO4) at 0, 15, 30 and 60 g m-2 yr-1 (F0, F15, F30 and F60) after 4 years of continuous fertilization on functional diversity and species diversity, and its relationship with productivity in an alpine meadow community on the Tibetan Plateau. To this purpose, three community-weighted mean trait values (specific leaf area, SLA; mature plant height, MPH; and seed size, SS) for 30 common species in each fertilization level were determined; three components of functional diversity (functional richness, FRic; functional evenness, FEve; and Rao's index of quadratic entropy, FRao) were quantified. Our results showed that: (i) species diversity sharply decreased, but functional diversity remained stable with fertilization; (ii) community-weighted mean traits (SLA and MPH) had a significant increase along the fertilization level; (iii) aboveground biomass was not correlated with functional diversity, but it was significantly correlated with species diversity and MPH. Our results suggest that decreases in species diversity due to fertilization do not result in corresponding changes in functional diversity. Functional identity of species may be more important than functional diversity in influencing aboveground productivity in this alpine meadow community, and our results also support the mass ratio hypothesis; that is, the traits of the dominant species influenced the community biomass production.

[Carbon sequestration status of forest ecosystems in Ningxia Hui Autonomous Region].

Based on the data of Ningxia Hui Autonomous Region forest resources inventory, field investigation and laboratory analysis, this paper studied the carbon sequestration status of forest ecosystems in Ningxia region, estimated the carbon density and storage of forest ecosystems, and analyzed their spatial distribution characteristics. The results showed that the biomass of each forest vegetation component was in the order of arbor layer (46.64 Mg x hm(-2)) > litterfall layer (7.34 Mg x hm(-2)) > fine root layer (6.67 Mg x hm(-2)) > shrub-grass layer (0.73 Mg x hm(-2)). Spruce (115.43 Mg x hm(-2)) and Pinus tabuliformis (94.55 Mg x hm(-2)) had higher vegetation biomasses per unit area than other tree species. Over-mature forest had the highest arbor carbon density among the forests with different ages. However, the young forest had the highest arbor carbon storage (1.90 Tg C) due to its widest planted area. Overall, the average carbon density of forest ecosystems in Ningxia region was 265.74 Mg C x hm(-2), and the carbon storage was 43.54 Tg C. Carbon density and storage of vegetation were 27.24 Mg C x hm(-2) and 4.46 Tg C, respectively. Carbon storage in the soil was 8.76 times of that in the vegetation. In the southern part of Ningxia region, the forest carbon storage was higher than in the northern part, where the low C storage was mainly related to the small forest area and young forest age structure. With the improvement of forest age structure and the further implementation of forestry ecoengineering, the forest ecosystems in Ningxia region would achieve a huge carbon sequestration potential.

Value of postoperative radiation therapy for regional control after dissection in head and neck squamous cell carcinoma cases.

OBJECTIVE: We aimed to define clinicopathologic risk factors associated with regional recurrence (RR) and thus the effectiveness of postoperative radiotherapy (PORT) for neck control for head and neck squamous cell carcinomas (HNSCCs) with differing cervical lymph node status. METHODS: A retrospective study was performed in 196 HNSCC patients with pathologically positive neck node (N+) to evaluate the high-risk factors for RR and to define the role of PORT in control after neck dissection and postoperative radiotherapy (PORT). RESULTS: Overall, the RR rate after neck dissection and PORT was 29%. Extracapsular spread (ECS) was confirmed to be the only independent risk factor for RR. There were no significant risk factors associated with RR in the ECS- group. The 5-year disease-specific survival rate was 45%, which descended to 10% with the emergence of RR. CONCLUSIONS: ECS remains a determined risk factor for RR after neck dissection and PORT in patients with N+. PORT alone is not adequate for preventing RR in the neck with ECS after neck dissection. More intensive postoperative adjuvant therapies, especially combined chemotherapy and radiotherapy, are needed to prevent regional failure in HNSCC patients with ECS.

[Fine root biomass of four main vegetation types in Daluo Mountain of Ningxia, Northwest China].

By the method of soil core sampling, this paper studied the fine root biomass, soil water content, and soil bulk density in 0-40 cm soil layer of four main vegetation types (Picea crassifolia forest, Pinus tabulaeformis forest, deciduous shrubs, and desert grassland) in Daluo Mountain of Ningxia, and the fine root biomass in the 0-40 cm soil layer of P. crassifolia forests with the ages of 50-, 70-, and 100 a. The fine root biomass of the four vegetation types was mainly distributed in 0-20 cm soil layer, with the rank of P. tabulaeformis forest > P. crassifolia forest > deciduous shrubs > desert grassland, and the fine root biomass of P. tabulaeformis forest was significantly higher than that of the other three vegetation types. The fine root biomass of the P. crassifolia forests with different ages was 70 a > 100 a > 50 a, and there were no significant differences in the live fine root biomass ratio and dead fine root biomass ratio among the three P. crassifolia forests. The soil water content in the 0-40 cm soil layer of the four vegetation types was P. crassifolia forest > P. tabulaeformis forest > deciduous shrubs > desert grassland, while the soil bulk density followed an opposite pattern, and was significantly negatively correlated with the fine root biomass.

[Allelopathic effects of Artemisia sacrorum population in typical steppe based on niche theory].

By using modified Levins niche width index and Pianka niche overlap index, this paper analyzed the ecological competition between constructive and dominant species in a typical steppe. The stem- and leaf extracts from the constructive species (Artemisia sacrorum) were utilized to study their allelopathic potential on the seed germination and plant growth of the dominant species (Stipa bungeana, Thymus mongolicus, S. grandis, and Leymus secalinus), and the ecological position of A. sacrorum in the steppe succession. In the steppe, S. bungeana had the widest niche width (0.99), followed by T. mongolicus (0.94), A. sacrorum (0.82), S. grandis (0.76), and L. secalinus (0.73). The niche overlap value between A. sacrorum and S. bungeana, S. bungeana and T. mongolicus, T. mongolicus and S. grandis, and A. sacrorum and T. mongolicus was 0.90, 0.95, 0.94, and 0.86, respectively. The allelopathic effects of A. sacrorum extracts varied with their concentration. For the seed germination, root growth, and shoot growth of the dominant species, A. sacrorum extracts showed a trend of promoting at low concentrations and inhibiting at high concentrations. The extracts of A. sacrorum had a stronger promotion effect on the root growth of S. bungeana than on that of T. mongolicus, but a stronger inhibition effect on the shoot growth of T. mongolicus than on that of S. bungeana. Methanol extracts had stronger allelopathic effects than aqueous extracts. The high niche overlap between A. sacrorum and S. bungeana, and T. mongolicus and S. grandis indicated that the steppe community would continue succession to S. bungeana, while A. sacrorum population was only an important transitional stage during the succession. The allelopathic effect of A. sacrorum played a driving role in the succession process.

[Outcomes of salvage laryngectomy after initial radiation failure in laryngeal squamous cell carcinoma].

OBJECTIVE: To investigate survival outcomes of salvage surgery preformed for laryngeal squamous cell carcinoma that recurred or progressed after radiotherapy alone. METHODS: A review of 72 patients who underwent salvage laryngectomy for laryngeal cancer failed in initial radiation therapy between 1996 and 2005 was performed. The tumor persistence occurred in 50 cases and recurrence in 22 cases. All patients received salvage total laryngectomy and radical neck dissection. Survival analysis was performed by using Kaplan-Meier method, Log-rank test and Cox proportional hazard model. RESULTS: Thirty patients developed a postoperative complication after salvage surgery. Pharyngocutaneous fistula occurred in 15(20.8%) patients. During 5 years after salvage surgery, the rates of tumor recurrence, distant metastasis and second malignancy were 34.7%, 22.2% and 6.9%, respectively. Kaplan-Meier analysis showed that overall 3 year and 5 year survival rates of those patients after operation were 45.8% and 36.1%, respectively. Univariate analysis indicated that N restage, tumor persistence/recurrences after radiotherapy, surgical margin status, level of tumor invasion, pathologic N stage, extracapsular nodal spread and invasion of nonlymphotic structures were significantly associated with overall survival. Multivariate analysis showed the most significant prognostic factors were tumor persistence or recurrence after radiotherapy, surgical margin status and level of tumor invasion. CONCLUSIONS: Surgical salvage remains the gold standard for management after failure of initial radiation therapy. The extent of tumor invasion must be assessed sufficiently before operation, and the surgical margin status must be identified in operation by using a frozen sectioning approach, especially in patients with tumor invasion to muscle/cartilage and tumor persistence after radiotherapy.

[Distribution responses of Lespedeza davurica community on Loess Plateau to climate change].

Field survey and position monitoring were conducted from 2000 to 2009 to study the effects of climate change on the distribution and growth of Lespedeza davurica community on Loess Plateau. As affected by air temperature, the appropriate growth region of L. davurica community on the Plateau had an obvious zonal distribution from northwest to southeast. For the distribution of L. davurica community, the suitable air temperature was 7.4 degrees C-10 degrees C, average population density was 13.9 plants x m(-2), and reproductive branch was averagely 11.4 per cluster. As affected by precipitation gradient, the horizontal distribution of L. davurica community changed from a constructive or predominant species in typical grassland region into a companion species in forest steppe region, and then, the community gradually became dominant species. The L. davurica community appeared as an occasional species on the half sunny slope of gullies and valleys and the sand dunes in desert steppe region, and extended gradually from its optimal region with yearly precipitation 300 -500 mm to the region with yearly precipitation 270-600 mm. Also, the L. davurica community extended from its optimal altitude 1100-1700 m to 600-1950 m. Under the background of global climate change, the eco-breadth of L. davurica community expanded gradually.

[Clinicopathologic aspects of locoregional recurrence of hypopharyngeal cancer and their implication on the survival of patients].

OBJECTIVE: To investigate the clinicopathologic aspects of locoregional recurrence and their implication on the survival in patients with hypopharyngeal cancer. METHODS: A retrospective review of 101 patients with hypopharyngeal cancer that were treated with surgical management and postoperative radiotherapy from 1998 to 2004 was performed. The clinicopathologic risk factors for locoregional recurrence were evaluated by using univariate chi(2) tests and multiple stepwise Logistic regression models. Survival analysis was performed by using Kaplan-Meier method, Log-Rank test and Cox proportional hazard model. RESULTS: The overall incidence of locoregional recurrence in this series of hypopharyngeal cancer was 43.6% (44/101). The rates of recurrence were local 13.9% (14/101), regional 31.7% (32/101). In a multivariate Logistic regression analysis, it was confirmed that number of levels with pathologic lymph node (OR = 0.334, P = 0.0242) was the most significant risk factors for locoregional recurrence. The same for regional recurrence was capsule rupture of pathologic lymph node (OR = 0.353, P = 0.0389) and multilevel positive nodal involvement in neck (OR = 0.259, P = 0.0069). The overall survival of hypopharyngeal cancer was 23.2%, and reduced to 11.4% for locoregional recurrence. The recurrences were managed by salvage surgery in 12 cases, which included local recurrences after partial pharyngolaryngectomy, ipsilateral regional recurrences after selective neck dissection, and contralateral regional recurrences at initially uninvolved neck. The overall survival of those patients sustained 33.3%. A multivariate Cox regression analysis revealed that the factors impacting the prognosis were recurrent time (RR = 0.317, P < 0.0001) and treatment modality after locoregional recurrence (RR = 6.119, P = 0.0001). CONCLUSIONS: Locoregional recurrences are frequent and have a very negative impact on patient survival in hypopharyngeal cancer, which most commonly have a regional recurrence. Salvage surgery in suitable cases seems to improve survival rates. Much attention should be paid to cervical pathological factors for locoregional recurrences in hypopharyngeal cancer, especially multilevel and capsule rupture of pathologic lymph node.

[Water potential productivity and soil desiccation effect of alfalfa grasslands in different type arid areas of Loess Plateau: a simulation study].

Based on model validation and database establishment, the dynamic changes of water potential productivity, available water amount in 0-10 m soil layer, and moisture distribution in soil profiles on the alfalfa grasslands at Changwu of semi-humid area, Guyuan of semi-arid area, and Haiyuan of semi-arid prone drought area on Loess Plateau were simulated with WinEPIC model in a 20-30 years period. The results showed that the simulated water potential productivity of alfalfa grasslands at Changwu, Guyuan and Haiyuan fluctuated but declined with precipitation, and the mean value was 8.81, 3.83 and 2.48 t x hm(-2), respectively. The simulated monthly available water amount in 0-10 m soil layer also declined obviously but with fluctuation. On the 4-8 years old alfalfa grasslands, soil desiccation was quite serious, and soil available water amount fluctuated at low level with precipitation for a long period. With the increasing year of alfalfa growth, the thickness and distribution depth of desiccated soil layer increased gradually, and the duration for the desiccated soil depth over 10 m was 6 years at Changwu, 6 years at Guyuan, and 4 years at Haiyuan. After then, the soil layer beneath rainfall infiltration depth lasted permanently in a desiccated status. The reasonable duration for water sustainable use on alfalfa grasslands was 8-10 years on semi-humid area, 6-8 years on semi-arid years, and 4-6 years on semi-arid prone drought area.

[Clinicopathologic features and prognostic factors of cervical lymph node metastasis in oral squamous cell carcinoma].

BACKGROUND & OBJECTIVE: The cervical lymphatic meta-static rate of oral squamous carcinoma is 50%-59%. The management of cervical lymphatic metastasis relates with prognosis of patients with oral squamous carcinoma. This study was to investigate the clinicopathologic features and prognosis factors of cervical lymph node metastasis in oral squamous cell carcinoma. METHODS: Clinicopathologic data of 191 patients with oral squamous cell carcinoma were retrospectively reviewed. The relationship between histopathologic factors and cervical lymph node metastasis was evaluated by univariate Chi(2) test. Cox regression model was used to analyze impacts of pathologic factors of cervical lymph nodes, such as metastatic status, size and number of positive neck nodes,levels of positive nodes, the lowest involved nodal level, on prognosis. RESULTS: The overall 5-year survival rate of the 191 patients was 48.7%. Univariate Chi(2) test confirmed that only depth of primary tumor infiltration correlated to cervical lymph node metastasis. Cox regression analysis revealed that clinical N stage, cervical lymphatic metastatic status, number of involved levels, and the lowest involved nodal level affected prognosis of patients, the most significant prognostic factors of cervical lymph node were clinical N stage, and the lowest involved nodal level. CONCLUSIONS: Cervical lymph node metastasis is a significant prognostic factor of oral squamous cell carcinoma. The identification of metastatic patterns of cervical lymph nodes, and the management targeting pathologic factors of cervical lymph node affecting survival are critical for improving the treatment effect on oral squamous cell carcinoma.

[Clinical analysis of 71 cases of multiple primary cancers in head and neck squamous carcinomas].

OBJECTIVE: To study the location, treatment, life status of multiple primary cancers (MPCs) in head and neck squamous cell carcinomas. METHODS: The clinical data of 71 head and neck squamous carcinoma patients with MPCs were retrospectively analyzed. RESULTS: MPCs were seen in head and neck regions in 27 cases and in remote organs in 42 cases, two of which were triplicate primary cancers. Four cases were synchronous MPCs, including one patient with synchronous triplicate primary cancer. Other 67 cases were heterochronous MPCs, including one patient with heterochronous triplicate primary cancer. Of 67 heterochronous MPCs, the time interval between index tumor presentation and diagnosis of MPCs was eight months to twelve years. MPCs occurred in seventy percent index oral cavity squamous cancers, which were located in head and neck regions, and in sixty-two percent index hypopharynx cancers and seventy-nine percent index laryngeal cancers, which were located in remote organs. The incidence of MPCs in esophagus and lung was higher than that in other remote organs. Among the various MPCs in this serials, the incidence of the disease appeared to be the highest in esophagus, accounting for twenty-four percent of all cases. The total three- and five-year survival rates were 32.4% and 22.5%, respectively. Of all MPCs patients, the three-year survival rate for patients who received different therapies for their MPCs was obviously higher than that of untreated patients (P < 0.01, Chi-square test). CONCLUSIONS: Esophageal carcinoma is the most common second primary cancer among the various MPCs of the head and neck squamous carcinomas. Oral cavity cancers tend to have more MPCs in the head and neck regions, and laryngeal and hypopharyngeal cancers are easily to be associated with MPCs in the remote organs. Regular follow-up and early diagnosis with effective treatment can help to improve the survival of MPC patients in head and neck squamous cell carcinomas.

[Analysis of risk factors in the prediction of distant metastases of head and neck squamous cell carcinomas].

OBJECTIVE: To investigate the risk factors related with distant metastases (DM) from head and neck squamous cell carcinomas (HNSCC). METHODS: A retrospective study was carried out to review the histopathological data from 532 HNSCC patients treated in Bethune International Peace Hospital from February 1978 to February 1998. The incidence and the risk factor for DM were evaluated in a model that included the following factors: sex, age, clinical staging, T and N staging, site of primary tumor, depth of primary tumor infiltration, histological grade of primary tumor, presence of cervical lymph node metastasis, number of positive neck nodes and levels involved, and presence of extracapsular nodal spread. Univariate chi2 test and multivariate stepwise logistic regression model were used for the analysis. Statistical analysis of overall survival was performed using Kaplan-Meier method. RESULTS: Sixty cases (11.3%) presented distant metastases in 532 patients of head and neck squamous cell carcinomas. In a univariate analysis, it was confirmed that the following variables correlated to DM, i.e., clinical staging (P = 0.0126), T classification (P = 0.0082), site of primary tumor (P = 0.0011), depth of primary tumor infiltration (P = 0.0005) , presence of cervical metastasis (P = 0.0057), number of positive neck nodes (P = 0.0149) and levels involved (P = 0.0034), presence of extracapsular nodal spread (P = 0.0118). In a multivariate analysis, the most significant risk factors for DM were the site of primary tumor and the depth of primary tumor infiltration. Kaplan-Meier analysis showed that overall survival rates of 60 HNSCC patients who presented distant metastases were 51.7% at 1 year, 13.3% at 3 years, 6.5% at 5 years, respectively. CONCLUSION: The site of primary tumor and the depth of primary tumor infiltration are the key risk factors in determining the development of DM in HNSCC patients. Patients with laryngeal and hypopharyngeal carcinomas and patients with primary tumor infiltrating muscular, bone or cartilage level have the highest risk of developing DM.

[Clinical pathology feature and prognostic factors of cervical lymph node metastases in hypopharyngeal carcinoma].

OBJECTIVE: To investigate the risk clinicopathological factors of primary tumor in the prediction of cervical lymph node metastases and the cervical lymph node prognostic factors in hypopharyngeal squamous cell carcinoma. METHODS: A retrospective study was carried out to review the histopathological data from 98 hypopharyngeal squamous cell carcinoma patients. The relationship between histopathological parameters and cervical lymph node metastases were evaluated by means of a univariate chi2 test and multivariate stepwise logistic regression model. And the Cox regression model was used to define possible pathological parameters of neck node affecting survival including N staging, presence of cervical lymph node metastases and extracapsular nodal spread, size and number of positive neck nodes, and levels of positive neck nodes. RESULTS: The overall 5-year survival rate of patients with hypopharyngeal carcinoma was 28.6%. In a univariate and multivariate analysis, it was confirmed that size and growth pattern of primary tumor correlated to cervical lymph node metastases. In a multivariate Cox regression analysis, the most significant prognostic factors of cervical lymph node were the size of positive neck nodes and level involved. CONCLUSIONS: Cervical lymph node metastases were one of the most significant prognostic factors of hypopharyngeal carcinoma. The identification of patients at risk for cervical lymph node metastases and the management of the neck by coping with pathological factors of cervical lymph node affecting survival are very important to improve the treatment and prognosis of hypopharyngeal carcinoma.