GATIS score:An innovative prognostic score for rectal neuroendocrine neoplasms

In this article,we discussed the article by Zeng et al,published in a recent issue of the World Journal of Gastroenterology.The publication represents a significant advancement in the prognostic evaluation of rectal neuroendocrine neoplasms.The GATIS score is a single nomogram model that incorporates five key progno-stic factors:Tumor grade;T stage;tumor size;age;and the prognostic nutritional index.This innovation optimizes the prognostic process,delivering more accurate predictions of overall survival and progression-free survival compared to tradi-tional TNM staging and World Health Organization classification systems.The findings of the study were based on a retrospective analysis spanning 12 years and involving 1408 patients from 17 reference centers in China.In this editorial,we specifically examined the strengths and limitations of the study,the clinical implications of the GATIS score,and the questions arising from its conclusions.

GATIS score for predicting the prognosis of rectal neuroendocrine neoplasms:A Chinese multicenter study of 12-year experience

BACKGROUND There is currently a shortage of accurate,efficient,and precise predictive instruments for rectal neuroendocrine neoplasms(NENs).AIM To develop a predictive model for individuals with rectal NENs(R-NENs)using data from a large cohort.METHODS Data from patients with primary R-NENs were retrospectively collected from 17 large-scale referral medical centers in China.Random forest and Cox proportional hazard models were used to identify the risk factors for overall survival and progression-free survival,and two nomograms were constructed.RESULTS A total of 1408 patients with R-NENs were included.Tumor grade,T stage,tumor size,age,and a prognostic nutritional index were important risk factors for prognosis.The GATIS score was calculated based on these five indicators.For overall survival prediction,the respective C-indexes in the training set were 0.915(95%confidence interval:0.866-0.964)for overall survival prediction and 0.908(95%confidence interval:0.872-0.944)for progression-free survival prediction.According to decision curve analysis,net benefit of the GATIS score was higher than that of a single factor.The time-dependent area under the receiver operating characteristic curve showed that the predictive power of the GATIS score was higher than that of the TNM stage and pathological grade at all time periods.CONCLUSION The GATIS score had a good predictive effect on the prognosis of patients with R-NENs,with efficacy superior to that of the World Health Organization grade and TNM stage.

Endoscopic ultrasonography-related diagnostic accuracy and clinical significance on small rectal neuroendocrine neoplasms

This research aimed to examine the diagnostic accuracy and clinical significance of endoscopic ultrasonography(EUS)in the context of small rectal neuroendocrine neoplasms(NENs).A total of 108 patients with rectal subepithelial lesions(SELs)with a diameter of<20 mm were included in the analysis.The diagnosis and depth assessment of EUS was compared to the histology findings.The prevalence of NENs in rectal SELs was 78.7%(85/108).The sensitivity of EUS in detecting rectal NENs was 98.9%(84/85),while the specificity was 52.2%(12/23).Overall,the diagnostic accuracy of EUS in identifying rectal NENs was 88.9%(96/108).The overall accuracy rate for EUS in assessing the depth of invasion in rectal NENs was 92.9%(78/84).Therefore,EUS demonstrates reasonable diagnostic accuracy in detecting small rectal NENs,with good sensitivity but inferior specificity.EUS may also assist physicians in assessing the depth of invasion in small rectal NENs before endoscopic excision.

Enhancing prognostic accuracy in predicting rectal neuroendocrine neoplasms

The recently published retrospective study introduces the GATIS score,a new predictive model for rectal neuroendocrine neoplasms.By analyzing data from a large Chinese multicenter cohort,the study shows that the GATIS score,incor-porating tumor grade,T stage,tumor size,age,and prognostic nutritional index,demonstrates superior predictive power for overall survival and progression-free survival compared to traditional World Health Organization grade and tumor,nodes and metastases staging systems.This editorial aims to discuss the impor-tance of the GATIS score,its potential impact on clinical practice,and the strengths and limitations of the study.Finally,it explores the significance,methodology,and clinical implications of these findings.

Evaluation of the GATIS score for predicting prognosis in rectal neuroendocrine neoplasms

The GATIS score,developed by Zeng et al,represents a significant advancement in predicting the prognosis of patients with rectal neuroendocrine neoplasms(RNENs).This study,which included 1408 patients from 17 major medical centres in China over 12 years,introduces a novel prognostic model based on the tumour grade,T stage,tumour size,age,and the prognostic nutritional index.Compared with traditional methods such as the World Health Organization classification and TNM staging systems,the GATIS score has superior predictive power for overall survival and progression-free survival.With a C-index of 0.915 in the training set and 0.812 in the external validation set,the GATIS score’s robustness and reliability are evident.The study’s use of a large,multi-centre cohort and rigorous validation processes underscore its significance.The GATIS score offers clinicians a powerful tool to accurately predict patient outcomes,guide treatment decisions,and improve follow-up strategies.This development represents a crucial step forwards in the management of R-NENs,addressing the complexity and variability of these tumours and setting a new benchmark for future research and clinical practice.

Postoperative chemoradiotherapy with capecitabine and oxaliplatin vs.capecitabine for pathological stage N2 rectal cancer

Objective:Several studies have been conducted on the effects and toxicity of adding oxaliplatin to fluorouracilbased or capecitabine-based chemoradiotherapy(CRT)regimens as significantly increasing the toxic response without benefit to survival.In this study,we further explored the role of these two postoperative CRT regimens in patients with pathological stage N2 rectal cancer.Methods:This study was a subgroup analysis of a randomized clinical trial.A total of 180 patients with pathological stage N2 rectal cancer were eligible,85 received capecitabine with radiotherapy(RT),and 95 received capecitabine and oxaliplatin with RT.Patients in both groups received adjuvant chemotherapy[capecitabine and oxaliplatin(XELOX);or fluorouracil,leucovorin,and oxaliplatin(FOLFOX)]after CRT.Results:At a median follow-up of 59.2[interquartile range(IQR),34.0−96.8]months,the three-year diseasefree survival(DFS)was 53.3%and 64.9%in the control group and the experimental group,respectively[hazard ratio(HR),0.63;95%confidence interval(95%CI),0.41−0.98;P=0.04].There was no significant difference between the groups in overall survival(OS)(HR,0.62;95%CI,0.37−1.05;P=0.07),the incidence of locoregional recurrence(HR,0.62;95%CI,0.24−1.64;P=0.33),the incidence of distant metastasis(HR,0.67;95%CI,0.42−1.06;P=0.09)and grade 3−4 acute toxicities(P=0.78).For patients with survival longer than 3 years,the conditional overall survival(COS)was significantly better in the experimental group(HR,0.39;95%CI,0.16−0.96;P=0.03).Conclusions:Our results indicated that adding oxaliplatin to capecitabine-based postoperative CRT is safe and effective in patients with pathological stage N2 rectal cancer.

Transanal Endoscopic Microsurgery (TEM) for Rectal Neoplasms

Introduction: The abdominal approach for the treatment of rectal tumors is associated with a considerable rate of morbidity. Transanal Endoscopic Microsurgery (TEM) is an alternative technique that is less invasive than radical surgery, and therefore has a lower associated morbidity. Moreover, with proper patient selection, TEM presents oncological outcomes comparable to radical surgery. The aim of this study is to review our results obtained with TEM and discuss its role in the treatment of malignant rectal lesions. Patients and Methods: A prospective descriptive study from June 2008 until February 2011. The indications for TEM were: early rectal neoplastic lesions (T1N0M0) with good prognostic factors;neoplastic lesions in more advanced stages in selected patients (high surgical risk, refusal of radical surgery or stoma, and palliative intention). Results: Resection by TEM was performed on 19 patients. The average hospital stay was 5.7 days with an associated morbidity of 16.7%. R0 resection was 88.8%. During the follow-up of 15 (3 - 31) months, no recurrence has been shown. Conclusions: TEM is a safe and effective procedure for the treatment of selected early malignant rectal lesions and is associated with low morbidity. It is a therapeutic strategy based on a multidisciplinary team, careful patient selection, an audited surgical technique and a strict follow-up protocol.

Innovative approaches in predicting outcomes for rectal neuroendocrine tumors

Rectal neuroendocrine neoplasms pose significant challenges due to their varied presentations and prognoses.Traditional prognostic models,while useful,often fall short of accurately predicting clinical outcomes for these patients.This article discusses the development and implications of a novel prognostic tool,the GATIS score,which aims to enhance predictive accuracy and guide treatment strategies more effectively than current methods.Utilizing data from a large cohort and employing sophisticated statistical models,the GATIS score integrates clinical and pathological markers to provide a nuanced assessment of prognosis.We evaluate the potential of this score to transform clinical decision-making processes,its integration into current medical practices,and future directions for its develo-pment.The integration of genetic markers and other biomarkers could further refine its predictive power,highlighting the ongoing need for innovation in the management of rectal neuroendocrine neoplasms.

Impact of technology on indications and limitations for transanal surgical removal of rectal neoplasms

Transanal surgery has and continues to be well accepted for local excision of benign rectal disease not amenable to endoscopic resection. More recently, there has been increasing interest in applying transanal surgery to local resection of early malignant disease. In addition, some groups have started utilizing a transanal route in order to accomplish total mesorectal excision(TME) for more advanced rectal malignancies. We aim to review the role of various transanal and endoscopic techniquesin the local resection of benign and malignant rectal disease based on published trial data. Preliminary data on the use of transanal platforms to accomplish TME will also be highlighted. For endoscopically unresectable rectal adenomas, transanal surgery remains a widely accepted method with minimal morbidity that avoids the downsides of a major abdomino-pelvic operation. Transanal endoscopic microsurgery and transanal minimally invasive surgery offer improved visualization and magnification, allowing for finer and more precise dissection of more proximal and larger rectal lesions without compromising patient outcome. Some studies have demonstrated efficacy in utilizing transanal platforms in the surgical management of early rectal malignancies in selected patients. There is an overall higher recurrence rate with transanal surgery with the concern that neither chemoradiation nor salvage surgery may compensate for previous approach and correct the inferior outcome. Application of transanal platforms to accomplish transanal TME in a natural orifice fashion are still in their infancy and currently should be considered experimental. The current data demonstrate that transanal surgery remains an excellent option in the surgical management of benign rectal disease. However, care should be used when selecting patients with malignant disease. The application of transanal platforms continues to evolve. While the new uses of transanal platforms in TME for more advanced rectal malignancy are exciting, it is important to remain cognizant and not sacrifice long term survival for short term decrease in morbidity and improved cosmesis.

Three-dimensional conformal radiotherapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer

AIM： To investigate the effect of three-dimensional conformal radiotherapy （3-DCRT） in combination with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer. METHODS： Forty-eight patients with unresectable recurrent rectal cancer were randomized and treated by 3-DCRT or 3-DCRT combined with FOLFOX4 chemotherapy between September 2001 and October 2003. For the patients without prior radiation history, the initial radiation was given to the whole pelvis by traditional methods with tumor dose of 40 Gy, followed by 3-DCRT for the recurrent lesions to the median total cumulative tumor dose of 60 Gy （range 56-66 Gy）; for the post-radiation recurrent patients, 3-DCRT was directly given for the recurrent lesions to the median tumor dose of 40 Gy （36-46 Gy）. For patients in the study group, two cycles chemotherapy with FOLFOX4 regimen were given concurrently with radiotherapy, with the first cycle given simultaneously with the initiation of radiation and the second cycle given in the fifth week for patients receiving conventional pelvis radiation or given in the last week of 3-DCRT for patients receiving 3-DCRT directly. Another 2-4 cycles （average 3.6 cycles） sequential FOLFOX4 regimen chemotherapy were given to the patients in the study group, beginning at 2-3 wk after chemoradiation. The outcomes of symptoms relieve, tumor response, survival and toxicity were recorded and compared between the study group and the control group. RESULTS： For the study group and the control group, the pain-alleviation rates were 95.2% and 91.3%（P〉 0.05）; the overall response rates were 56.5% and 40.0% （P〉0.05）; the 1-year and 2-year survival rates were 86.9%, 50.2% and 80.0%, 23.9%, with median survival time of 25 mo and 16 mo （P〈 0.05）; the 2-year distant metastasis rates were 39.1% and 56.0% （P= 0.054）, respectively. The side effects, except peripheral neuropathy which was relatively severer in the study group, were similar in the the two groups and well tolerated. CONCLUSION： Three-dimensional conformal radiotherapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer is a feasible and effective therapeutic approach, and can reduce distant metastasis rate and improve the survival rate.

Neoadjuvant vs adjuvant pelvic radiotherapy for locally advanced rectal cancer: Which is superior?

The treatment of locally advanced rectal cancer including timing and dosage of radiotherapy, degree of sphincter preservation with neoadjuvant radiotherapy, and short and long term effects of radiotherapy are controversial topics. The MEDLINE, Cochrane Library databases, and meeting proceedings from the American Society of Clinical Oncology, were searched for reports of randomized controlled trials and meta-analyses comparing neoadjuvant and adjuvant radiotherapy with surgery to surgery alone for rectal cancer. Neoadjuvant radiotherapy shows superior results in terms of local control compared to adjuvant radiotherapy. Neither adjuvant or neoadjuvant radiotherapy impacts overall survival. Short course versus long course neoadjuvant radiotherapy remains controversial. There is insufficient data to conclude that neoadjuvant therapy improves rates of sphincter preserving surgery. Radiation significantly impacts anorectal and sexual function and includes both acute and long term toxicity. Data demonstrate that neoadjuvant radiation causes less toxicity compared to adjuvant radiotherapy, and specifically short course neoadjuvant radiation results in less toxicity than long course neoadjuvant radiation. Neoadjuvant radiotherapy is the preferred modality for administering radiation in locally advanced rectal cancer. There are significant side effects from radiation, including anorectal and sexual dysfunction, which may be less with short course neoadjuvant radiation.

Intraoperative intraperitoneal chemotherapy increases the incidence of anastomotic leakage after anterior resection of rectal tumors

BACKGROUND Intraoperative intraperitoneal chemotherapy is an emerging treatment modality for locally advanced rectal neoplasms. However, its impacts on postoperative complications remain unknown. Anastomotic leakage (AL) is one of the most common and serious complications associated with the anterior resection of rectal tumors. Therefore, we designed this study to determine the effects of intraoperative intraperitoneal chemotherapy on AL. AIM To investigate whether intraoperative intraperitoneal chemotherapy increases the incidence of AL after the anterior resection of rectal neoplasms. METHODS This retrospective cohort study collected information from 477 consecutive patients who underwent an anterior resection of rectal carcinoma using the double stapling technique at our institution from September 2016 to September 2017. Based on the administration of intraoperative intraperitoneal chemotherapy or not, the patients were divided into a chemotherapy group (171 cases with intraperitoneal implantation of chemotherapy agents during the operation) or a control group (306 cases without intraoperative intraperitoneal chemotherapy). Clinicopathologic features, intraoperative treatment, and postoperative complications were recorded and analyzed to determine the effects of intraoperative intraperitoneal chemotherapy on the incidence of AL. The clinical outcomes of the two groups were also compared through survival analysis. RESULTS The univariate analysis showed a significantly higher incidence of AL in the patients who received intraoperative intraperitoneal chemotherapy, with 13 (7.6%) cases in the chemotherapy group and 5 (1.6%) cases in the control group (P = 0.001). As for the severity of AL, the AL patients who underwent intraoperative intraperitoneal chemotherapy tended to be more severe cases, and 12 (92.3%) out of 13 AL patients in the chemotherapy group and 2 (40.0%) out of 5 AL patients in the control group required a secondary operation (P = 0.044). A multivariate analysis was subsequently performed to adjust for the confounding factors and also showed that intraoperative intraperitoneal chemotherapy increased the incidence of AL (odds ratio = 5.386;95%CI: 1.808-16.042;P = 0.002). However, the survival analysis demonstrated that intraoperative intraperitoneal chemotherapy could also improve the disease-free survival rates for patients with locally advanced rectal cancer. CONCLUSION Intraoperative intraperitoneal chemotherapy can improve the prognosis of patients with locally advanced rectal carcinoma, but it also increases the risk of AL following the anterior resection of rectal neoplasms.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypl stage after neoadjuvant chemo-radiotherapy versus de novo stage pl cohort:A propensity score-matched analysis

Objective：Prognosis of patients with locally advanced rectal cancer（LARC）but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy（CRT）has been shown to be favorable.This study aims to determine whether the long-term outcome of yp T1–2N0 cases can be comparable to that of p T1–2N0 cohort that received definitive surgery for early disease.Method：From January 2008 to December 2013,449 consecutive patients with rectal cancer were treated and their outcome maintained in a database.Patients with LARC underwent total mesorectal excision（TME）surgery at4–8 weeks after completion of CRT,and those achieving stage yp I were identified as a group.As a comparison,stage p I group pertains to patients whose initially limited disease was not upstaged after TME surgery alone.After propensity score matching（PSM）,comparisons of local regional control（LC）,distant metastasis-free survival（DMFS）,disease-free survival（DFS）and overall survival（OS）were performed using Kaplan-Meier analysis and log-rank test between yp I and p I groups.Down-staging depth score（DDS）,a novel method of evaluating CRT response,was used for subset analysis.Results：Of the 449 patients,168 matched cases were generated for analysis.Five-year LC,DMFS,DFS and OS for stage p I vs.yp I groups were 96.7%vs.96.4%（P=0.796）,92.7%vs.73.6%（P=0.025）,91.2%vs.73.6%（P=0.080）and 93.1%vs.72.3%（P=0.040）,respectively.In the DDS-favorable subset of the yp I group,LC,DMFS,DFS and OS resulted in no significant differences in comparison with the p I group（P=0.384,0.368,0.277 and0.458,respectively）.Conclusions：LC was comparable in both groups;however,distant metastasis developed more frequently in down-staged LARC than de novo early stage cases,reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response.DDS can be an indicator to identify a subset of the yp I group whose longterm oncologic outcomes are as good as those of stage p I cohort.

Selective lateral lymph node dissection after neoadjuvant chemoradiotherapy in rectal cancer

BACKGROUND Lateral lymph node metastasis is one of the leading causes of local recurrence in patients with advanced mid or low rectal cancer.Neoadjuvant chemoradiotherapy(NCRT)can effectively reduce the postoperative recurrence rate;thus,NCRT with total mesorectal excision(TME)is the most widely accepted standard of care for rectal cancer.The addition of lateral lymph node dissection(LLND)after NCRT remains a controversial topic.AIM To investigate the surgical outcomes of TME plus LLND,and the possible risk factors for lateral lymph node metastasis after NCRT.METHODS This retrospective study reviewed 89 consecutive patients with clinical stage II-III mid or low rectal cancer who underwent TME and LLND from June 2016 to October 2018.In the NCRT group,TME plus LLND was performed in patients with short axis(SA)of the lateral lymph node greater than 5 mm.In the non-NCRT group,TME plus LLND was performed in patients with SA of the lateral lymph node greater than 10 mm.Data regarding patient demographics,clinical workup,surgical procedure,complications,and outcomes were collected.Multivariate logistic regression analysis was performed to evaluate the possible risk factors for lateral lymph node metastasis in NCRT patients.RESULTS LLN metastasis was pathologically confirmed in 35 patients(39.3%):26(41.3%)in the NCRT group and 9(34.6%)in the non-NCRT group.The most common site of metastasis was around the obturator nerve(21/35)followed by the internal iliac artery region(12/35).In the NCRT patients,46%of patients with SA of LLN greater than 7 mm were positive.The postoperative 30-d mortality rate was 0%.Two(2.2%)patients suffered from lateral local recurrence in the 2-year follow up.Multivariate analysis showed that cT4 stage(odds ratio[OR]=5.124,95%confidence interval[CI]:1.419-18.508;P=0.013),poor differentiation type(OR=4.014,95%CI:1.038-15.520;P=0.044),and SA≥7 mm(OR=7.539,95%CI:1.487-38.214;P=0.015)were statistically significant risk factors associated with LLN metastasis.CONCLUSION NCRT is not sufficient as a stand-alone therapy to eradicate LLN metastasis in lower rectal cancer patients and surgeons should consider performing selective LLND in patients with greater LLN SA diameter,poorer histological differentiation,or advanced T stage.Selective LLND for NCRT patients can have a favorable oncological outcome.

Usefulness of two independent hist classifications of tumor regression iUsefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM： To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy. METHODS： Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy （42 Gy during 18 d） and then to radical surgical treatment. The relationship between ＂T-downstaging＂ versus regressive changes expressed by tumor regression grade （TRG 1-5） and Nasierowska-Guttmejer classification （NG 1-3） was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN. RESULTS： Complete regression （ypT0, TRG 1） was found in one patient. ＂T-downstaging＂ was observed in 11 （27.5%） patients. There was a weak statistical significance of the relationship between ＂T-downstaging＂ and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRGS. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG. CONCLUSION： Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patients with rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between ＂Todownstaging＂ and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

Genetic polymorphisms in genes regulating cell death and prognosis of patients with rectal cancer receiving postoperative chemoradiotherapy

Objective:The identification of biomarkers for predicting chemoradiotherapy efficacy is essential to optimize personalized treatment.This study determined the effects of genetic variations in genes involved in apoptosis,pyroptosis,and ferroptosis on the prognosis of patients with locally advanced rectal cancer receiving postoperative chemoradiotherapy(CRT).Methods:The Sequenom MassARRAY was used to detect 217 genetic variations in 40 genes from 300 patients with rectal cancer who received postoperative CRT.The associations between genetic variations and overall survival(OS)were evaluated using hazard ratios(HRs)and 95%confidence intervals(CIs)computed using a Cox proportional regression model.Functional experiments were performed to determine the functions of the arachidonate 5-lipoxygenase(ALOX5)gene and the ALOX5 rs702365 variant.Results:We detected 16 genetic polymorphisms in CASP3,CASP7,TRAILR2,GSDME,CASP4,HO-1,ALOX5,GPX4,and NRF2 that were significantly associated with OS in the additive model(P<0.05).There was a substantial cumulative effect of three genetic polymorphisms(CASP4 rs571407,ALOX5 rs2242332,and HO-1 rs17883419)on OS.Genetic variations in the CASP4 and ALOX5 gene haplotypes were associated with a higher OS.We demonstrated,for the first time,that rs702365[G]>[C]represses ALOX5 transcription and corollary experiments suggested that ALOX5 may promote colon cancer cell growth by mediating an inflammatory response.Conclusions:Polymorphisms in genes regulating cell death may play essential roles in the prognosis of patients with rectal cancer who are treated with postoperative CRT and may serve as potential genetic biomarkers for individualized treatment.

Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma

A clinical trial of radiotherapy with modified simultaneous integrated boost(SIB)technique against huge tumors was conducted.A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial.The total dose of 77 Gy(equivalent dose in 2Gy/fraction)and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively,andapproximately 20%dose escalation was achieved with the modified SIB technique.The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy.Performance status of the patient improved from 4 to 0.Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance,improvement of QOL,and prolongation of survival.

Evaluation of fecal occult blood test with reverse passive hemagglutination for colorectal neoplasm screen *

AIM To evaluate the one sampling and three sampling reverse passive hemagglutination fecal occult blood test (RPHA FOBT) for colorectal neoplasm screening.

Dosimetric study of five-field intensity-modulated radiotherapy compared with conventional three-dimensional conformal radiotherapy for rectal cancer

Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional three-dimensional conformal radiotherapy （3DCRT） in the radiotherapy of rectal cancer. Methods： Fifteen patients with rectal cancer treated with radio- therapy （RT） were retrospectively analyzed. Among the patients, seven received RT preoperatively and 8 postoperatively. The target volume and the OARs such as the small bowel, bladder and femoral heads were contoured for each patient. 3DCRT-plan and IMRT-plan were performed for each patient respectively, with the prescribed dose covering at least 95% of the planning target volume （PTV）. The conformity index （CI） and homogeneity index （HI） were used for evaluation of the dose distribution in the target volume, and the Dx% （the lowest dose to the x% volume of the OARs that received the highest dose of irradiation） and the mean dose were used for evaluation of the dose to OARs. Paired-T test was used for companson of the difference between the two plans. Results： In the IMRT-plan and 3DCRT-plan, the CI were 0.94 and 0.87 （P = 0.000） and the HI were 1.13 and 1.17, respectively （P = 0.001）. For small bowel, the D30%, D50% and the mean dose were 19.67 Gy, 15.13 Gy and 18.81 Gy in the IMRT-plan and 25.20 Gy, 22.20 Gy and 22.89 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For bladder, the D30%, D50%, and the mean dose were 24.80 Gy, 34.20 Gy and 28.70 Gy in the IMRT- plan, and 35.07 Gy, 44.67 Gy and 35.68 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For femoral heads, the D5% in the IMRT-plan and 3DCRT-plan were 40.6 Gy and 40.47 Gy, respectively （P = 0.936）, and the mean dose were 30.14 Gy and 25.57 Gy, respectively （P = 0.001）. Conclusion： Five-field IMRT-plan is better than 3DCRT-plan in the conformity and the dose homogeneity within target volume and also better in sparing the small bowel and bladder.

The predictive value of vascular endothelial growth factor and Ki-67 expression on neoadjuvant therapy in rectal cancer

Objective： To investigate the expressions of vascular endothelial growth factor （VEGF） and proliferating cell nuclear antigen （Ki-67） in patients with rectal adenocarcinoma and their associations with neoadjuvant therapy. Methods： The expressions of Ki-67 and VEGF in 32 cases of rectal adenocarcinoma, including both pretreatment tumor biopsies and postoperative specimen, were detected by immunohistochemistry using specific antibodies, and were correlated with clinicopathological factors. Results： The intensity of VEGF staining was significantly correlated with lymph nodal metastasis （P =0.033）, depth of tumor invasion （P =0.007） and tumor stage （P= 0.016）, but not with histological types, tumor sizes, patients＇ ages and genders （P 〉 0.05）. Low level of VEGF expression had significant correlation with the high sensitivity of response to neoadjuvant therapy （P = 0.016）. The transient increase of VEGF expression could be seen after neoadjuvant therapy （P = 0.035）. Ki-67 labeling index （Ki-67-LI） was significantly correlated with lymph node metastasis （P = 0.028）, but not correlated to tumor sizes, patients＇ ages and genders （P 〉 0.05）. Tumors with lower Ki-67-LI were more sensitive to neoadjuvant therapy （P = 0.032）. The Ki-67 level decreased after neoadjuvant therapy, but no statistical significance was found （P 〉 0.05）. Conclusion： Our results demonstrate that the expression of VEGF and Ki-67 in pretreatment rectal adenocarcinoma biopsies may be predictive of tumor response to neoadjuvant therapy.