The Effect Of Postoperative Adjuvant Chemotherapy On Recurrence-free Survival In Patients With Stage Ⅱ Non-small Cell Lung Cancer

Background:Lung cancer is a highly malignant tumor,which mainly includes two types:small cell lung cancer(Small Cell Lung Cancer,SCLC)and non-small cell lung cancer(Non-small Cell Lung Cancer,NSCLC).Compared with NSCLC,SCLC is easy to distant metastasis and sensitive to chemotherapy.It is generally believed that surgical resection is the most effective treatment for NSCLC in the early and middle stage.However,in the end,some patients died as a result of recurrence and metastasis.Postoperative adjuvant chemotherapy is an effective way to reduce the recurrence rate,and there are differences in the efficacy of adjuvant chemotherapy among different patients.Clinical staging can be used to guide postoperative chemotherapy in patients with NSCLC.At present,chemotherapy is not recommended for patients with stage I NSCLC,and routine adjuvant chemotherapy for patients with stage ⅡB and stageⅢ A has been widely recognized.With the introduction of the TNM staging system of the eighth edition of lung cancer,some of the patients who originally belonged to stageⅠB belong to the newly defined stage ⅡA.there is no agreement on whether these patients need adjuvant chemotherapy at home and abroad,so it is necessary to carry out relevant research.ObjectiveTo investigate the effect of postoperative adjuvant chemotherapy on relapse-free survival ofⅡstage patients with NSCLC,and to provide theoretical basis for postoperative treatment of Ⅱstage patients with NSCLC.MethodA retrospective study was conducted on patients with stageⅡNSCLC who underwent radical surgery in our Hospitals from January 2014 to January 2016.the basic information,diagnosis,treatment and follow-up information of the patients were collected.The recurrence of the patients was determined by querying the medical records and telephone follow-up.According to whether the patients were treated with adjuvant chemotherapy or not,the patients were divided intopostoperative chemotherapy group and non-chemotherapy group,and the postopera-tive recurrence of the two groups was compared,and the subgroup analysis ofⅡpatients was carried out.The effects of adjuvant chemotherapy on relapse-free survival of patients with ⅡA and ⅡB were compared,SPSS21.0 statistical software was used for analysis,the number and constituent ratio of counting data were expressed,the mean ±standard deviation was used to express the measurement data,and the patients in the two groups were compared.Independent sample t test was used to measure the data,chi-square test was used to count the data,and Kaplan-Meier survival analysis method was used to draw the recurrence-free survival curve of the patients after operation.The risk factors of tumor differentiation,vascular invol-vement and visceral pleural invasion were analyzed according to the risk factors ofⅡA stage,and the survival differences of each factor were compared by Log-rank method.P < 0.05 was considered to be statistically significant,and the risk ratio(Hazard Ratio,HR)and 95% confidence interval(95%CI)were calculated.Result1.A total of 160 people were included,with an average age of 60.8 years ±7.8,of which 78 cases(48.8%)were in ⅡA stage,82 cases(51.2%)were in ⅡB stage.The median follow-up period was 32 months.during the follow-up period,71 cases(44.4%)recurred and 89 cases(55.6%)did not recur.The 1-year,2-year and 3-year recurrence-free survival rates were 86.13%,64.36% and 56.76%,respectively.2.Postoperative adjuvant chemotherapy reduced the risk of recurrence of NSCLC inⅡby 40%(HR 0.6,95% CI 0.4-1.0,P = 0.057),but close to 0.05.Postoperative chemotherapy reduced the risk of recurrence in ⅡA patients by 10%(HR 0.9,95% CI 0.4-1.8,P = 0.72).The risk of postoperative chemotherapy recurrence in ⅡB patients decreased by 50%(HR 0.5,95% CI 0.3-0.9,P = 0.03).3.In stage Ⅱ A patients,the risk of recurrence in patients with pleural involvement was 2.3 times higher than that in patients without pleural involvement(HR 2.3,95% CI 1.1-4.8,P < 0.03).The risk of recurrence in patients with vascular invasion was 2.5 times higher than that in patients without vascular invasion(HR 2.5,95% CI 1.1 5.8,P < 0.027).The risk of postoperative recurrence in patients with low differentiation was 2.6 times higher than that in patients with moderate and highdifferentiation(HR 2.6,95% CI 1.1 6.1,P < 0.027).4.In patients with ⅡA stage,adjuvant chemotherapy had a tendency to improve the relapse-free survival rate of patients with pleural infiltration,but did not achieve statistical significance.Adjuvant chemotherapy could improve the relapse-free survival rate of poorly differentiated patients(P = 0.042),which was statistically significant.Postoperative chemotherapy did not improve the recurrence-free survival rate of patients with vascular infiltration.Conclusion1.Postoperative adjuvant chemotherapy can prolong the recurrence-free survival time of patients with stage ⅡB,and patients with stage ⅡB should be treated with routine chemotherapy to reduce the risk of recurrence.2.Poor tumor differentiation,vascular invasion and pleural involvement were the risk factors for recurrence after NSCLC in ⅡA stage.3.Postoperative adjuvant chemotherapy may reduce the risk of recurrence in stage ⅡA patients with poorly differentiated tumors.