Validation of the eighth edition of the AJCC staging system for patients with pancreatic adenocarcinoma initially receiving chemoradiotherapy and proposal of modifications

Objective:To validate the eighth edition of the AJCC staging system in patients with pancreatic adenocarcinoma receiving only stereotactic body radiation therapy and chemotherapy,and to propose modifications to improve prognostic accuracy.Methods:Patients with pathologically confirmed pancreatic adenocarcinoma without metastasis who were undergoing only chemoradiotherapy were included and staged according to the seventh and eighth editions of the AJCC staging system.Meanwhile,another group of stage T4 patients from the above enrollment with only portal vein involvement with or without tumor thrombi(PV±PVTT)were retrieved for survival comparisons.Modifications were proposed according to the survival comparisons.A cohort from the SEER database was used for external validation of the modified staging system.Results:A total of 683 patients were included.Patients with N2 or N1 but different T stages had significantly different survival outcomes according to the eighth edition.The survival of patients with(PV±PVTT)was comparable to that of patients with T4 tumors.The concordance index of the seventh and eighth editions,and the modified staging system was 0.744(95%CI:0.718—0.769),0.750(95%CI:0.725—0.775),and 0.788(95%CI:0.762-0.813),respectively.For external validation,the concordance index was 0.744(95%CI:0.718-0.770),0.750(95%CI:0.724-0.776),and 0.788(95%CI:0.762-0.814),respectively.Conclusions:The modified staging system is suggested to have the m ost accurate prognostic value.Hence,PV土PVTT should be added to the definition of T4 tumors regardless of tumor size.Patients with N2 or N1 in different T stages could be regrouped into different substages.Additionally,stage III should be subclassified into IIIA(T3N 2 and T4N 0)and IIIB(T4N 1-2).

A homogenized approach to classify advanced gastric cancer patients with limited and adequate number of pathologically examined lymph nodes

Background:The prognosis of gastric cancer patients with a limited number of pathologically examined lymph nodes(eLN,<16)is dismal compared to those with adequately eLN(≥16),yet they are still classified within the same subgroups using the American Joint Committee on Cancer(AJCC)staging system.We aimed at formulating an easy-to-adopt and clinically reliable stratification approach to homogenize the classification for these two categories of patients.Methods:Patients staged according to the 8th AJCC pathological nodal(N)and tumor-node-metastasis(TNM)clas-sification were stratified into a Limited and Adequate eLN cohort based on their number of pathologically examined LNs.The statistical differences between the 5-year overall survival(OS)rates of both cohorts were determined and based on which,patients from the Limited eLN cohort were re-classified to a proposed modified nodal(N′)and TNM(TN′M)classification,by matching their survival rates with those of the Adequate eLN cohort.The prognostic perfor-mance of the N′and TN′M classification was then compared to a formulated lymph-node-ratio-based nodal classifica-tion,in addition to the 8th AJCC N and TNM classification.Results:Significant heterogeneous differences in 5-year OS between patients from the Limited and Adequate eLN cohort of the same nodal subgroups were identified(all P<0.001).However,no significant differences in 5-year OS were observed between the subgroups N0,N1,N2,and N3a of the Limited eLN cohort when compared with N1,N2,N3a,and N3b from the Adequate eLN cohort,respectively(P=0.853,0.476,0.114,and 0.230,respectively).A novel approach was formulated in which only patients from the Limited eLN cohort were re-classified to one higher nodal subgroup,denoted as the N′classification.This re-classification demonstrated superior stratifying and prognostic ability as compared to the 8th AJCC N and lymph-node-ratio classification(Akaike information criterion values[AIC]:12,276 vs.12,358 vs.12,283,respectively).The TN′M classification also demonstrated superior prognostic ability as compared to the 8th AJCC TNM classification(AIC value:12,252 vs.12,312).Conclusion:The proposed lymph node classification approach provides a clinically practical and reliable technique to homogeneously classify cohorts of gastric cancer patients with limited and adequate number of pathologically examined lymph nodes.

Clinicopathological features and impact of adjuvant chemotherapy on the long-term survival of patients with multiple gastric cancers:a propensity score matching analysis

Background:Little is known about the correlation between the clinicopathological features,postoperative treatment,and prognosis of multiple gastric cancers(MGCs).In this study,we aimed to investigate the correlation between these features and the impact of postoperative adjuvant chemotherapy on the long-term survival of patients with MGC.Methods:The clinical and pathological data of patients diagnosed with gastric adenocarcinoma who had radical gastrectomy from January 2007 to December 2016 were analyzed.Using propensity score matching,the prognostic differences,and the impact of postoperative adjuvant chemotherapy between those with MGC and solitary gastric cancers(SGC)were compared.Results:Among the 4107 patients investigated,the incidence of MGC was 3.2%(133/4107).Before matching,patients with MGC and SGC had disparities in the type of gastrectomy,pathological tumor stage(pT),pathological node stage(pN),and pathological tumor-node-metastasis stage(pTNM).After a 1:4 ratio matching,the clinical data of 133 cases of MGC and 532 cases of SGC were found to be comparable.The 5-year overall survival(OS)rate was 56.6%in the entire matched cohort,48.1%in the MGC group,and 58.7%in the SGC group(P=0.013).Multivariate analysis revealed that MGC,age,pT stage,pN stage,and adjuvant chemotherapy were independent predictors of OS(all P<0.05).Stratified analyses demonstrated that for the cohort of advanced gastric cancer(AGC)patients who did not had adjuvant chemotherapy,the 5-year OS rate of advanced cases of MGC was inferior than that of SGC patients(34.0%vs.46.1%,respectively;P=0.025)but there were no significant difference in the 5-year OS rate between advanced MGC and SGC patients who had adjuvant chemotherapy(48.0%vs.53.3%,respectively;P=0.292).Further,we found that the 5-year OS rate of advanced MGC who had adjuvant chemotherapy was significantly higher than those who did not had adjuvant chemotherapy(48.0%vs.34.0%,P=0.026).Conclusions:Patients with advanced MGC was identified as having a poorer survival as to SGC patients,but the implementation of postoperative adjuvant chemotherapy showed that it had the potential to significantly improve the long-term prognoses of MGC patients.