Clinicopathological Features Of Bilateral Primary Breast Cancer At Different Diagnostic Intervals

Objective:To explore the correlation between interval time of diagnosis in patients with bilateral primary breast cancer（BPBC）with the clinicopathological characteristics,including age,tumor size,lymph node status,Body Mass Index（BMI）,estrogen receptor（ER）,progesterone receptor（PR）,and human epidermal growth factor receptor-2（HER2）status.Methods:In this study,the medical records information of BPBC patients was collected from January 1^st,2008 to December 31^st,2016 at the Breast Center of the Fourth Hospital of Hebei Medical University.Using the diagnostic interval of 6 months as the cut-off point,patients with a diagnosis interval less than 6 months after first diagnosis were SBBC and patients with interval more than 6 months were MBBC.Results:In this study,a total of 248 patients were collected,including110 cases of SBBC（44.4%）,and 138 cases of MBBC（55.6%）,and the MBBC patients were increasing by years（P<0.05）.Among MBBC patients,70patients（51%）with a diagnosis interval of less than 60 months,and 68patients（49%）had a diagnosis interval of more than 60 months.Under the groups of≤6 months,6-60 months,and>60 months,the proportion of Hormone Receptor（HR）-positive breast cancer patients with HR-positive contralateral breast cancer（CBC）was lower in the 6-60 months group than other two groups.While the proportion of HR-negative breast cancer patients with HR-negative CBC was increased with increasing interval.With the same grouping,we used multivariate generalized logistic regression model include age,BMI,tumor size and lymph node status to analysis the relationship between HR and HER2 status of first breast cancer and diagnosis interval.In the 6-60 months group versus≤6 months group,the age of diagnosis（>50 vs.≤40）was associated with the time interval of BPBC in each subgroup（P<0.05）,and the PR（positive Vs.negative,OR=0.602,95%CI=0.285-1.270,P=0.02）and the HER2（positive vs.negative,OR=0.449,95%CI=0.196-1.274,P=0.02）status of first breast cancer were also associated with the time interval.In the>60 months versus≤6 month group,HER2（positive vs.negative,OR=0.479,95%CI=0.146-1.577,P=0.04）status of first breast cancer was associated with the diagnosis time interval of BPBC.The HR consistency of both sides of breast cancer showed no significant difference in each group.Conclusion:Our study shows that the MBBC patients are increasing by years,and 49%MBBC patients with a diagnosis interval of more than 5 years,suggesting that breast cancer patients should be followed up regularly even after 5 years of breast cancer surgery,in order to detect the second cancer in time.The HR consistency of bilateral breast cancer did not vary in each diagnosis interval group.It may not a proper choice to distinguish SBBC and MBBC by the association of HR.The age of diagnosis,HR,and HER2 status of the first breast cancer have a significant effect on the diagnosis interval time of BPBC.