Restaging Of Solitary Distant Lymph Node Metastasis In First Diagnosed Breast Cancer

Objective:For a long time,solitary distant lymph node metastasis of breast cancer has been considered as a kind of advanced distant metastasis of breast cancer,TNM stage belongs to stage Ⅳ,and systemic drug palliative treatment should be given.However,in recent years,more and more studies have shown that SDLNM should be a local regional metastatic disease,and local radical surgery can often achieve good results.At present,most of the relevant studies are case reports,with different opinions from experts and lack of systematic research.Therefore,the purpose of this paper is to explore whether SDLNM is a local regional metastatic disease or a late distant metastatic disease,and to provide a relatively reliable basis for clinicians to make treatment decisions.Methods:Five groups of patients with ipsilateral supraclavicular lymph node metastasis(Tn N3 c M0),SDLNM,distant organ metastasis(Tn Nn M1)(excluding distant lymph node metastasis),regional metastasis(regional)and distant metastasis(excluding distant lymph node metastasis)of breast cancer diagnosed from 2016 to 2019 were retrieved,downloaded and screened using the National Cancer Institute Surveillance,Epidemiology and Results Database.Kaplan-Meier survival analysis was used to draw the survival curve,log-rank test was used to compare the total survival rate(OS)differences among the three groups of patients with Tn N3 c M0,SDLNM,and Tn Nn M1,and the total survival rate(OS)differences among the three groups of patients with different molecular subtypes,Fine-Gray test was used to compare the differences among the total survival rate(BCSS)differences among the three groups of patients with different molecular subtypes,and COX stepwise regression was used to study the total survival rate prognosis differences and risk ratio(HR)among the three groups of patients with different molecular subtypes,To preliminarily explore the clinical stages of SDLNM and/or SDLNM molecular typing.Results:1.Preliminary study of three groups(Tn N3 c M0、SDLNM、Tn Nn M1)of patients:1.1 Log-Rank test and Kaplan-Meier survival curve showed that for the total population and patients with TNBC,there were differences in OS prognosis among the three groups(P;For Luminal type A patients,there was no significant difference in OS prognosis between SDLNM and Tn N3 c M0 patients(P=0.775),but there was significant difference in OS prognosis between SDLNM and Tn Nn M1 patients(P=0.006);For HER2 positive patients and Luminal B patients,there was no significant difference in OS prognosis among the three groups(P>0.05).Among them,Tn N3 c M0patients had the best OS prognosis,followed by SDLNM,and Tn Nn M1 OS had the worst prognosis.1.2 The Fine-Gray test was used to control the competitive risk events,and the CIF curve showed that the prognosis of the three groups of patients was different(P;For patients with Luminal type,the prognosis of BCSS in SDLNM and Tn N3 c M0patients is similar(Luminal A: P=0.820,Luminal B: P=0.257)P=0.775,and there is a difference in the prognosis of BCSS between SDLNM and Tn Nn M1 patients(Luminal A: P=0.003,Luminal B: P=0.004);For HER2 positive patients,there was no significant difference in the prognosis of the three groups of patients(P>0.05).The prognosis of BCSS in Tn N3 c M0 patients was the best,followed by SDLNM,and the prognosis of BCSS in Tn Nn M1 patients was the worst.1.3 After adjusting the influence of other variables by COX regression(forward stepwise method),it was found that for the total population and Luminal A patients,the OS prognosis of SDLNM patients and Tn N3 c M0 patients was more similar,while the OS prognosis of patients with distant organ metastasis(excluding distant lymph node metastasis)was significantly different;For other molecular typing,there was no significant difference in OS prognosis among SDLNM patients,Tn N3CM0 patients and Tn Nn M1 patients.2.Further study of three groups(Regional、SDLNM、Distant)of patients:2.1 Log-Rank test and K-M curve showed that for the total population and Luminal A patients,the OS prognosis of the three groups of patients was different(P<0.001).The OS prognosis of patients with regional metastasis was the best,followed by SDLNM,and the OS prognosis of patients with distant metastasis was the worst.2.2 The Fine-Gray test was used to control the competition risk event,and the CIF curve showed that for the total population,the prognosis of BCSS of SDLNM patients and Distant patients was similar(P=0.827),but there was a difference between BCSS of regional patients(P<0.001);For Luminal type A patients,there were differences in the prognosis of BCSS among the three groups(P<0.001,P=0.036).The prognosis of BCSS in regional patients was the best,followed by SDLNM,and the prognosis of BCSS in distance patients was the worst.2.3 COX regression(forward stepwise method)was used to adjust the influence of other variables;The OS prognosis of SDLNM was similar to that of regional group(P=0.883),but it was significantly different from that of distance group(HR: 1.943,95%CI: 1.212～3.104,P=0.005).Conclusions:1.SDLNM is a locally recurrent breast cancer,and different molecular types have different survival prognosis.2.The OS prognosis of Luminal A type SDLNM is more similar to that of Tn N3 c M0 patients,and better than that of Tn Nn M1 patients;However,there was no significant difference in OS prognosis between SDLNM of other molecular types and Tn N3 c M0 and Tn Nn M1 patients.3.Further,the OS prognosis of Luminal A type SDLNM is similar to that of regional patients,and superior to that of Distant patients.4.We should recognize Luminal type A SDLNM patients again,classify their clinical stages as regional metastasis N3,and classify the clinical stages of other molecular types of SDLNM patients as advanced distant metastasis IV.