Background PM_2.5 pollution has become a widely concerned environmental health problem. Polycyclic aromatic hydrocarbons(PAHs) are the main harmful components of PM_2.5, and their sources and carcinogenic risk deserve attention. Objective To analyze the source apportionment of PAHs in ambient PM_2.5 in Fuzhou, and to evaluate the potential carcinogenic risk through inhalation due to exposure to PAHs. Methods In this study, two sampling sites were set up in Cangshan (industrial area) and Taijiang (commercial and residential area) districts in Fuzhou City. PM_2.5 was collected from 10th to 16th of each month from 2017 to 2020 by membrane filtration method. The concentrations of ambient PM_2.5 were measured by weighing, and the concentrations of 16 PAHs, including naphthalene(NAP), acenaphthylene(ACY), acenaphthene(ACE), fluorene(FLU), phenanthrene(PHE), anthracene(ANT), fluoranthene(FLT), pyrene(PYR), benzo[a]anthracene(BaA), chrysene(CHR), benzo[b]fluoranthene(BbF), benzo[k]fluoranthene(BkF), benzo[a]pyrene(BaP), indeno[1,2,3-cd]pyrene(IcdP), dibenzo[a,h]anthracene(DahA), and benzo[g,h,i]perylene(BghiP), were determined by ultra-high performance liquid chromatography coupled with diode array detector and fluorescence detector. The concentrations of PM_2.5 and PAHs were compared in the two districts and the concentrations of PAHs were also compared in different seasons. The diagnostic ratio [FLT/(FLT+PYR), IcdP/(IcdP+BghiP), BaA/(BaA+CHR), and BaP/BghiP] method and positive matrix factorization (PMF) analysis were used to determine the sources of PAHs in PM_2.5 in Fuzhou. The excess carcinogenic risk (ECR) model was used to assess the potential health risk of inhalation exposure to PAHs. Results During 2017–2020, the M (P₂₅, P₇₅) concentration of ambient PM_2.5 in Cangshan and Taijiang districts of Fuzhou were 35.0 (25.0, 47.5) and 34.0 (25.5, 46.0) μg·m⁻³ respectively, and the percentages of PM_2.5 exceeding the national standard in Cangshan and Taijiang were 2.68% and 4.17%, respectively, without significant differences (P＞0.05). The M (P₂₅, P₇₅) concentrations of ΣPAHs in Cangshan was 5.03 (3.07, 7.67) ng·m⁻³, higher than that in Taijiang, 3.20 (2.05, 5.59) ng·m⁻³ (P＜0.05). The M (P₂₅, P₇₅) concentrations of PAHs monomers except ACY, FLU, and ACE in Cangshan were higher than those in Taijiang (P＜0.05). The concentrations of ΣPAHs in PM_2.5 in four seasons in Cangshan were higher than those in Taijiang (P＜0.05). In both districts, the concentration of ΣPAHs in winter was higher than those in spring, summer, and autumn (P＜0.05). According to the diagnostic ratio method, the median ratios of FLT/(FLT+PYR) in the two districts ranged from 0.4 to 0.5, and those of IcdP/(IcdP+BghiP), BaA/(BaA+CHR), and BaP/BghiP were from 0.2 to 0.5, from 0.2 to 0.35, and less than 0.6, respectively. The results of PMF analysis showed the proportions of four factors in Cangshan were 37.9%, 13.2%, 24.0%, and 24.9%, respectively. The major load contributors to factor 1 included FLT, PHE, and PYR; to factor 2, FLU, ACY, and ACE; to factor 3, DahA; to factor 4, BghiP, IcdP, and BaP. The proportions of four factors in Taijiang were 23.6%, 19.3%, 22.0%, and 35.1%, respectively. The main load contributor to factor 1 was DahA; to factor 2, BghiP; to factor 3, FLT, PHE, and PYR; to factor 4, IcdP, BaP, BbF, BkF, CHR, and BaA. The benzo[a]pyrene equivalences (BEQ) in Cangshan and Taijiang districts were 1.87 ng·m⁻³ and 1.61 ng·m⁻³, respectively. The excess carcinogenic risks of PAHs through inhalation exposure was 3.83×10⁻⁶ and 3.30×10⁻⁶, respectively. Conclusion The complex sources of PAHs in ambient PM_2.5 include dust, vehicle emissions, industrial emissions in Fuzhou, and are different in selected two districts. The level of PAHs in ambient PM_2.5 may pose a potential carcinogenic risk to local population.

Objective:To investigate the safety and prognostic value of neoadjuvant chemotherapy and surgery for advanced gastric cancer patients with para-aortic lymph node metastasis.Methods:Clinicopathological data of 25 patients admitted to the Department of Gastrointestinal Surgery, Fujian Cancer Hospital from Jan 2015 to Jun 2017 were retrospectively analyzed. All patients were treated with SOX chemotherapy for 3 cycles. D 2 + paraaortic lymphadenectomy was performed in patients with stable disease (SD) . After operation, SOX regimen was used for 5 cycles of chemotherapy. Results:After 3 cycles of neoadjuvant chemotherapy, there were 2 cases with progressive disease, 6 cases of SD and 17 cases of partial remission. There was no treatment-related death. Twenty-three patients underwent surgery, including 19(76%) patients of R 0 resection. Tirty-four out of 128 para aortic lymph nodes were metastatic. Postoperative complications occurred in 5(22%) patients, with no mortality . The median progression free survival time and median overall survival time were 20 and 29 months respectively. The 1, 3-year overall survival rates were 80% and 48%, and the 1-year and 3-year progression free survival rates were 72% and 38%, respectively. For those with para-aortic lymph node metastasis the 1-year and 3-year OS rate were 70% and 17%, respectively. Multivariate analysis showed that the efficacy of neoadjuvant chemotherapy was an independent prognostic factor. Conclusion:Neoadjuvant chemotherapy is among others an independent prognostic factor affecting the post-op survival of advanced gastric carcinoma with para-aortic lymph node metastasis.

Objective:To evaluate the effects of ultrasound-guided quadratus lumborum block (QLB) on acute pain after total hip arthroplasty.Methods:A retrospective study was conducted of the 36 patients with hip osteoarthritis who had undergone selective one-side total hip arthroplasty under total intravenous anesthesia (TIVA) from January 2019 to January 2020. According to whether additional QLB was used or not they were divided into 2 equal groups ( n=18). The control group of 10 males and 8 females with an age of 60.5±9.4 years used mere TIVA while the QLB group of 7 males and 11 females with an age of 53.6±12.7 years used TIVA plus QLB. All patients accepted patient-controlled intravenous analgesia (PCIA) postoperatively. The 2 groups were compared in terms of visual analogue scale (VAS) at rest and during exercise and IL-6 level at 24 h postoperation, consumption of opioids and postoperative incidence of nausea and vomiting. Results:There were no significant differences between the 2 groups in their preoperative general data, indicating they were compatible ( P>0.05). The VAS scores at rest and during exercise in the QLB group (0.3 ± 0.5 and 0.8 ± 0.6) were significantly lower than in the control group (2.1 ± 0.7 and 2.7 ± 0.5), the IL-6 level in the former[40.9 (30.5, 56.3) pg/mL] was significantly lower than in the latter[165.0 (82.5, 276.5) pg/mL], the intraoperative total consumptions of sufentanil[6 (6, 7) μg] and remifentanil[1,370 (1,200, 1,485) μg] in the former were significantly lower than in the latter[35 (30, 40) μg and 1, 910 (1, 805, 2, 000) μg], and the postoperative incidenceof nausea and vomiting[27.8%(5/18)] in the former was significantly lower than in the latter[77.8%(14/18)] (all P<0.05). Conclusions:Ultrasound-guided quadratus lumborum block can effectively relieve acute pain in patients after total hip arthroplasty. It can suppress stress-related inflammatory factors, reduce consumption of opioids and incidence of postoperative nausea and vomiting.

Objective To analyze the risk factor of delayed gastric emptying (DGE) and the impact of DGE on prognosis after radical gastrectomy of distal gastric carcinoma.Methods The clinical and pathological data of 1 447 distal gastric cancer patients undergoing gastrectomy from Jul 2007 to Jan 2018 at Fujian Tumour Hospital was analyzed retrospectively.Result DGE was found in 101 patients (7.0％),occurring at a median of (6.0 ± 2.1) d after surgery.It was significantly correlated with age,diabetes,hypoproteinemia,preoperative pyloric obstruction,operation time,surgical mode,anastomotic procedure,postoperative analgesia(all P ＜ 0.05).Multivariate analysis showed that hypoproteinemia,diabetes,pyloric obstruction in preoperative period,surgical mode,postoperative analgesia,anastomotic procedure were independently associated with DGE.The average hospitalization time for DGE was significantly higher than patients with non DGE(16.3 ± 4.2) d vs.(8.1 ± 2.1) d,P ＜ 0.05.The five-year survival of patients with DGE and non DGE were 54.9％ and 54.2％ respectively(P ＞0.05) Conclusion DGE prolonged hospital stay,but did not influence patients' prognosis.

OBJECTIVETo evaluate the safty and feasibility of the D2 radical resection of omental bursa and No.12p and No.8p for gastric carcinoma (GC).

METHODSClinical data of 1801 GC patients undergoing D2 radical resection of omental bursa and No.12p and No.8p at Fujian Medical University Cancer Hospital from January 2000 to January 2010 were analyzed retrospectively. Inclusion case criteria: (1)age of 18 to 90 years;(2)pathologically diagnosed as GC and receiving D2 radical resection of omental bursa and No.12p and No.8p;(3)complete clinical, pathological and follow-up data; (4)operation performed by same leading surgeon;(5)exclusion of other gastric malignancies, postoperative relapse of GC, and other simultaneous or heterochronous primary malignancies. Surgical procedure points: (1)The outer part of the peritoneum of duodenum descending was cut; the serosa was migrated to the anterior leaf of the gastrointestinal ligament. (2)The posterior lobe of the gastrocolic ligament and the transverse mesocolon were separated bluntly from left side to reach the omentum attaching to the colon portion; incision was made at the edge of the omentum attaching to the transverse colon behind the gastrocolic ligament; the leaves were turned to the anterior mesenteric anterior leaflets, and the entire anterior leaflet of the transverse mesentery was free.(3)The pancreas was separated, and resection of the posterior wall of the omentum sac continued up so that the entire retinal capsule was free; along the edge of the liver the attachment of the omentum was cut to reach the front of esophagus, and transverse incision was made in abdominal peritoneal layer of the esophagus, and then turned to the spleen on the pole; from the obturator to the esophagus incision was performed behind the peritoneum for the net; the uppermost edge of the resection of the capsule was performed as the posterior peritoneal incision to the right edge of the esophagus and was connected with the posterior parietal lobe of the previous resection; the posterior peritoneum was attached along the right edge of the esophagus and descended to the celiac artery; the posterior wall of the omental sac was removed. In the meantime, the liver duodenum ligament was cut, and the portal vein, hepatic artery trilocular was formed. Then the ligament lymph nodes were cleared.(4)The lymph nodes of celiac artery and its major branches were cleared; the envelope in front of pancreas and the part of the pancreas in posterior abdomen were resected; spleen and part of the pancreas tail were free.

RESULTSA total of 1801 cases were enrolled, including 1292 males and 509 females with a ratio of 2.54 with a mean age of(58.9±11.5)(18 to 89) years. The proportion of cases with T1a, T1b, T2, T3, T4a and T4b was 4.8% (87 cases), 6.6% (118 cases), 10.7% (193 cases), 17.5% (315 cases), 55.7% (1003 cases) and 4.7%(85 cases) respectively. All the patients completed operations successfully. The mean number of harvested lymph node was 28.5±13.7(10 to 85). Lymph node metastasis was found in 1439 cases (79.9%), including 180 cases (10.0%) in No.12p and 232 cases(12.9%) in No.8p respectively. Subgroup analysis showed that in T1a, T1b, T2, T3, T4a and T4b stage, the proportion of No.12p was 0, 1.7% (2/118), 5.2%(10/193), 10.5% (33/315), 12.4% (124/1003) and 12.9%(11/85) respectively, and the proportion of No.8p was 0, 0.8%(1/118), 2.1%(4/193), 4.8%(15/315), 18.9%(190/1003), and 25.9%(22/85) respectively. Postoperative complications were found in 195 patients (10.8%), including 63 cases(3.5%) of peritoneal infection, 52 cases (2.9%) of pulmonary infection, 33 cases(1.8%) of pancreatic leakage, 37 cases (2.1%) of anastomotic fistula, 45 cases (2.5%) of intestinal obstruction and 13 cases(0.7%) of gastroplesia. The 5-year overall survival rate was 53.6%.

CONCLUSIOND2 radical resection of omental bursa and No.12p and No.8p is safe and feasible in the treatment of gastric cancer.

OBJECTIVETo analyze the feasibility of No.8p lymphadenectomy for the patients with advanced gastric cancer and to preliminaryly explore its value in improving prognosis.

METHODSClinical data of 1158 patients with advanced gastric cancer undergoing radical gastrectomy plus D2 or above D2 lymphadenectomy (No.8 lymphadenectomy) from July 2003 to July 2013 at Department of Gastrointestinal Surgery, Fujian Cancer Hospital were collected. A retrospective cohort study was carried out. Among 1158 patients, 343 patients from July 2003 to June 2008 only received No.8a lymph node dissection (No.8a group), and 815 patients from July 2008 to July 2013 received No.8a+No.8p lymph node dissection (No.8a+No.8p group). Patients in No.8a group received the dissection of the lymph nodes in the upper margin of the pancreas and the front of total hepatic artery, and those in No.8a+No.8p group, on the basis of No.8a group, received the dissection of lymph nodes in the common hepatic artery and the left lymph nodes behind the hepatic artery and the portal vein. The metastasis degree and metastasis rate of lymph node(No.8a and No.8p), as well as intraoperative and postoperative presentations in both groups were investigated. The prognosis of two groups were analyzed with Kaplan-Meier method and Log-rank test.

RESULTSAmong 1158 patients with advanced gastric cancer, 849 were males and 309 were females with aged 17 to 83(58.5 ±11.7) years. Radical distal gastrectomy was performed in 325 cases (28.1%) and radical total gastrectomy in 833 cases(71.9%). All the patients completed operations successfully. A total of 2587 No.8a lymph nodes were removed, and the lymph node metastasis rate and metastasis degree of No.8a were 20.6% (239/1158) and 13.0%(336/2587), respectively. A total of 2170 No.8p lymph nodes were removed, and the lymph node metastasis rate and metastasis degree of No.8p were 10.9%(89/815) and 7.2%(156/2170), respectively. The operation time of the No.8a+No.8p group was longer than that of No.8a group [(180.2±40.3) minutes vs. (168.4±41.8) minutes], and the difference was statistically significant (t=-4.627, P=0.000). However, intraoperative blood loss [(222.8±92.8) ml vs. (215.6±91.1) ml], postoperative 1-day peritoneal drainage volume [(257.7±120.0) ml vs. (270.3±121.0) ml], time to withdraw of gastric tube [(2.1±0.9) days vs. (2.2±0.8) days], time to withdraw of peritoneal tube [(6.8±1.1) days vs. (6.9±1.1) days], time to withdraw of nasal feeding tube[(6.5±1.2) days vs. (6.4±1.1) days], the morbidity of complications [19.8%(68/343) vs. 16.0%(130/815)] and postoperative hospital stay [(8.1±3.0) days vs.(8.3±3.1) days] in No.8a group and No.8a+No.8p group were not significantly different(all P>0.05). The average follow-up period was 41(2 to 144) months. The median postoperative survival was 83.0 months, and the 1-, 2-, and 5-year survival rates were 90.9%, 78.8% and 56.9% in No.8a group respectively. The median survival was 94.8 months, 1-, 2-, and 5-survival rates were 94.9%, 82.3% and 63.0% in No.8a+No.8p group respectively. The survival rate of No.8a+No.8p group was significantly higher than that of No.8a group (P=0.016). The stratified analysis showed that in stage II patients, the survival rate of No.8a+No.8p lymph node dissection was significantly higher than that of only No.8a lymph node dissection(P=0.021), but difference of survival between two groups was not significantly different in stage I patients(P=0.469) and stage III patients (P=0.820).

CONCLUSIONFor the patients with advanced gastric cancer, the dissection of No.8a+No.8p is safe and feasible, and may improve the prognosis, especially for those with stage II, suggesting that No.8a+No.8p lymphadenectomy should be performed for selected patients with advanced gastric cancer.

Objective To evaluate the clinicopathologic characteristics and prognosis of gastric stump cancer in relation to serum albumin level.Methods The clinical data of 149 gastric stump cancer patients treated from Jan 1999 to Jun 2015 were analyzed.Patients were divided into normal serum albumin group (＞ 35 g/L,n =81) and group of hypoalbuminemia (≤ 35 g/L,n =68).Results Clinicopathologic characteristics,tumor size,depth of invasion,lymph node status and TNM stage were significantly different between the two groups (P ＜ 0.05).Univariate analysis showed that factors that influence prognosis were serum albumin level,tumor size,serosal invasion,tumor location and tumor curative resection rate (all P ＜ 0.05).Cox's proportional hazard regression model showed that serum albumin level and tumor curative resection rate were independent prognostic factors for survival,lymph node matastasis(2.2 ±4.3) vs.(4.1 ±4.4)were significantly different between the two groups (P ＜0.05).The overall 5-year survival rate was 44.1％.The 5-year survival rate were 54.0％ for normal albumin group and 32.2％ for hypoalbuminemic group,P =0.011.Conclusion Lower preoperative serum albumin level is associated with poorer prognosis in gastric stump cancer patients.

OBJECTIVETo explore the risk factors and prognosis of No.8p lymph node metastasis in cases with advanced gastric cancer.

METHODSClinicopathological and follow-up data of 790 cases with advanced gastric cancer undergoing gastrectomy (including No.8p lymphadenectomy) from October 2003 to October 2013 in Fujian Provincial Tumor Hospital were analyzed retrospectively. Patients receiving neoadjuvant chemotherapy were excluded. Associations of No.8p lymph node metastasis with clinicopathological characteristics and metastasis in other regional lymph node were analyzed. Prognostic difference between positive No.8p group and negative No.8p group was examined.

RESULTSPositive No.8p lymph node was found in 93 cases (11.8%) among 790 cases with advanced gastric cancer. Univariate analysis showed that gender [male 9.8%(56/572) vs. female 17.0%(37/218), P=0.005], preoperative CEA level [<5 μg/L 28.0%(61/218) vs. ≥5 μg/L 5.6%(32/572), P=0.005], tumor size[diameter <5 cm 3.8%(13/346) vs. ≥5 cm 18.0%(80/445), P=0.000], tumor location [gastric fundus and cardiac 10.7% (26/244) vs. gastric body 13.5% (30/222) vs. gastric antrum 10.1% (31/308) vs. total gastric 37.5%(6/16), P=0.007], Borrmann staging [type II( 1.9%(4/211) vs. type III( 11.6% (54/464) vs. type IIII( 30.4%(35/115), P=0.000], tumor differentiation [high 0/8 vs. moderate 6.7%(25/372) vs. low 16.6%(68/410), P=0.000], T staging [T2 2.4%(4/170) vs. T3 13.1%(35/267) vs. T4 15.3%(54/353), P=0.000], N staging [N0 0 (0/227) vs. N1 2.2%(5/223) vs. N2 15.2%(26/171) vs. N3 36.7%(62/169), P=0.000] were closely associated with the No.8p lymph node metastasis. Multivariate analysis that revealed gender (OR=1.762, 95%CI: 1.020-3.043), tumor size (OR=1.107, 95%CI: 1.020-1.203), N staging (OR=4.093, 95%CI: 2.929-5.718), tumor differentiation (OR=1.782, 95%CI:1.042-3.049), and metastasis in No.8a(OR=5.370, 95%CI: 3.425-8.419), No.3(OR=1.127, 95%CI:1.053-1.206), No.6(OR=1.221,95%CI: 1.028-1.450), No.7(OR=2.149, 95%CI: 1.711-2.699), No,11p(OR=2.085, 95%CI: 1.453-2.994), No.14v(OR=2.604, 95%CI: 1.038-6.532) group lymph nodes were the independent risk factors of No.8p lymph node metastasis. One-year, 3-year and 5-year survival rates in positive No.8p group were 85.7%, 47.5% and 22.6%, and those in negative No.8p group were 96.2%, 82.5% and 70.3% respectively, whose differences were significant (χ=109.767, P<0.05).

CONCLUSIONSMetastasis in Np.8p lymph nodes is an important factor affecting the prognosis of patients with advanced gastric cancer. In patients with female gender, tumor diameter ≥5 cm, preoperative late N staging, low tumor differentiation or metastasis in No.8a, No.3, No.6, No.7, No.11p, No.14v group lymph nodes, thorough clean rance of No.8p group lymph node should be considered.

Carcinoembryonic Antigen ; blood ; Female ; Gastrectomy ; Humans ; Lymph Node Excision ; methods ; Lymph Nodes ; physiopathology ; surgery ; Lymphatic Metastasis ; diagnosis ; pathology ; physiopathology ; Male ; Multivariate Analysis ; Neoplasm Grading ; statistics & numerical data ; Neoplasm Staging ; statistics & numerical data ; Prognosis ; Retrospective Studies ; Risk Factors ; Sex Factors ; Stomach Neoplasms ; diagnosis ; mortality ; surgery ; Survival Rate

Objective To analyze the relationship of lymphovascular invasion (LVI) and the clinical pathological feature of gastric cancer and impact on the prognosis in gastric cancer patients.Methods The clinical and pathological data of 1 482 gastric cancer patients undergoing gastrectomy were analyzed retrospectively.The relationship between LVI and the prognosis was evaluated.Results LVI was found in 606 patients (40.9％),which was in significant correlations with tumor size,tumour location,Borrmann type,tumor differentiation status,operative method,tumor invasion,lymph node involvement,and TNM stage (P ＜ 0.05).The five-year survival of patients with LVI was significantly shorter than that of the LVI-negative patients (55.0％ vs.73.1％,x2 =45.15,P =0.00).By multivariate analysis,LVI was an independent prognostic factor (HR =1.592,95％ CI:1.329-1.907,P =0.00).Conclusion LVI is au important indicator for poor prognosis of gastric cancer,suggesting a more aggressive postoperative therapies.

Objective To investigate the relationship between perineural invasion and clinicopathological factors of gastric cancer or prognosis of patients.Methods The retrospective case-control study was conducted.The clinicopathological data of 1 801 patients with gastric cancer who were admitted to the Affiliated Tumor Hospital of Fujian Medical University between March 1999 and November 2015 were collected.All the patients received surgery in order to the radical resection of gastric cancer,and total gastrectomy or two-thirds and above of gastrectomy and D2 lymph node dissection were performed.Patients with preoperative stage Ⅲ of clinical staging underwent neoadjuvant chemotherapy.Patients with T3-T4 of histopathologic stage,T1-T2 of positive lymph nodes and T2N0 of high risk factors (low differentiated tumor,lymphovascular invasion,perineural invasion and age ＜ 50 years) underwent postoperative chemotherapy.Observation indicators:(1) treatment situations;(2)pathological characteristics;(3) follow-up results;(4) prognostic factors.Follow-up using outpatient examination and telephone interview was performed once within 1 month postoperatively,once every 3 months within 2 years postoperatively and once every 6 months from 3 to 5 years postoperatively up to February 2016.Follow-up included inquiry,physical examination,routine blood test,biochemical test,carcinoembryonic antigen (CEA),CA19-9,color Doppler ultrasound or computed tomography (CT) and endoscopy.Measurement data with normal distribution were represented as (x)±s and comparison between groups was analyzed using the t test.Measurement data with skewed distribution were described as M (range).Ordinal data was analyzed by the nonparametric test.The univariate analysis and multivariate analysis were done using the COX regression model.The hazard ratio (HR)and 95％ confidence interval (CI) were calculated.The survival curve and survival analysis were respectively drawn and done by the Kaplan-Meier method and Log-rank test.Result (1) Treatment situations:all the 1 801patients underwent traditional open surgery,including 1 570 undergoing radical resection and 231 undergoing palliative surgery.Of 1 801 patients,1 029 received total gastrectomy,540 received distal gastrectomy,201 received extended gastrectomy and 31 received resection of residual stomach.Operation time,volume of intraoperative blood loss,number of lymph node dissected and duration of hospital stay were (173±40) minutes,(224-±91) mL,30± 13 and (15±9) days,respectively.Of 1 801 patients,79 underwent preoperative neoadjuvant chemotherapy and 906 underwent postoperative adjuvant chemotherapy.(2) Pathological characteristics:results of pathological examinations of 1 801 patients showed that 509 had positive perineural invasion and 1 292 had negative perineural invasion.Tumors located in the upper region,middle region and lower region of stomach,whole stomach and stump stomach were respectively detected in 173,189,123,12,12 patients with positive perineural invasion and 395,417,428,29,23 patients with negative perineural invasion.Type Ⅰ,Ⅱ,Ⅲ and Ⅳ of Borrmann type were respectively detected in 13,213,244,39 patients with positive perineural invasion and 92,511,629,60 patients with negative perineural invasion.The good and poor tumor differentiations and tumor diameter ＜5 cm and ≥5 cm were respectively detected in 172,337,244,265 patients with positive perineural invasion and 536,756,833,459 patients with negative perineural invasion.Stage Ⅰ,Ⅱ,Ⅲ,Ⅳv of histopathologic stage,T1,T2,T3,T4 of invasive depth,NO,N1,N2,N3 of lymph node metastasis and positive and negative lymphovascular invasion were respectively detected in 27,54,346,82,17,24,26,442,77,84,109,239,383,126 patients with positive perineural invasion and 263,283,623,123,188,169,289,646,409,219,312,352,437,855 patients with negative perineural invasion,with statistically significant differences in above indexes between positive and negative perineural invasion patients (X2 =14.142,Z =-2.098,X2 =9.061,41.536,Z=-10.389,-13.824,-8.638,X2 =252.624,P＜ 0.05).(3) Follow-up results:1 629patients were followed up for 1.0-99.0 months,with a median time of 37.3 months.The 5-year overall survival rate was 58.5％.(4) Prognostic factors:results of univariate analysis showed that tumor location,Borrmann type,degree of tumor differentiation,tumor diameter,histopathologic stage,invasive depth,lymph node metastasis,lymphovascular invasion and perineural invasion were factors affecting prognosis of patients with gastric cancer (HR=1.209,1.303,1.496,2.303,3.368,2.057,1.812,2.013,1.332,95％ CI:1.123-1.301,1.171-1.449,1.290-1.736,2.001-2.649,3.012-3.767,1.856-2.279,1.694-1.939,1.749-2.317,1.126-1.576,P＜0.05).Resuhs of multivariate analysis showed that tumors located in the upper and middle of stomach,whole stomach and stump stomach,tumor diameter ≥ 5 cm,stage Ⅱ-Ⅳ of histopathologic stage,T2-T4 of invasive depth,N1-N3 of lymph node metastasis,positive lymphovascular invasion and positive perineural invasion were independent risk factors affecting prognosis of patients with gastric cancer (HR =1.087,1.234,2.663,1.174,1.136,1.254,1.272,95％ CI:1.008-1.172,1.063-1.432,2.292-3.095,1.035-1.332,1.044-1.236,1.064-1.501,1.066-1.516,P＜0.05).The 5-year survival rate was 49.1％ in 509 patients with positive perineural invasion and 60.7％ in 1 292 patients with negative perineural invasion,respectively,with a statistically significant difference (X2 =11.270,P＜0.05).The 5-year overall survival rate was 41.1％ in 383patients with positive perineural invasion and lymphovascular invasion,77.1％ in 126 patients with positive perineural invasion and negative lymphovascular invasion,49.1％ in 437 patients with negative perineural invasion and positive lymphovascular invasion and 92.1％ in 855 patients with negative perineural invasion and lymphovascular invasion,respectively,with a statistically significant difference (X2=244.368,P＜0.05).Conclusion Perineural invasion is a high risk factor affecting prognosis of patients with gastric cancer,and it may be useful in evaluating prognosis of patients with gastric cancer.