Pathological And Prognostic Features Of Primary Squamous Cell Carcinoma Of The Breast

Background:Primary squamous cell carcinoma of the breast(PSCCB)is a relatively rare specialty breast cancer,belonging to the metaplastic carcinoma of the breast,which accounts for less than 0.1%of all breast cancers.Compared with invasive ductal carcinoma of the breast,this tumor has faster growth rate and the pathological characteristics are similar to the basal-like subtype of breast tumor,and it is a type of breast cancer with a higher degree of malignancy.Its clinical manifestations and imaging features are not characteristic.At present,the diagnosis of PSCCB mainly relies on histopathological methods,and its diagnosis and treatment methods lack unified guidelines,and the prognosis and influencing factors remain unclear.Objective:By comparing PSCCB with common triple negative type invasive ductal carcinoma of breast,the clinical biological characteristics,pathological characteristics and treatment of PSCCB were analyzed,and related factors affecting prognosis were explored,providing reference for clinical standard diagnosis and treatment of PSCCB.Methods:A retrospective study was conducted on the clinicopathological data of 46 patients with PSCCB treated in the First Affiliated Hospital of Zhengzhou University and the Department of Breast Surgery of The People’s Hospital of Zhengzhou University from December 2009 to December 2018(squamous cell carcinoma group).A simple random sampling method was used to collect the clinicopathological data of 80 patients with triple negative invasive ductal carcinoma of breast(triple negative group).Paraffin sections of breast cancer tissues from both groups were collected.The pathological properties and estrogen receptor(ER),progesterone receptor(PR),human epidermal growth factor receptor-2(Her-2),Ki-67,epidermal growth factor receptor(EGFR),CK5/6 and P53 were verified.Immunohistochemistry was used to detect the expression of Platelet endothelial cell adhesion molecule-1(PECAM-1/CD31)in paraffin sections of breast cancer tissues from 126 patients.The clinicopathological data of patients with PSCCB and triple negative invasive ductal carcinoma of breast were collected and analyzed,including gender,age,tumor size at diagnosis,lymph node metastasis,distant metastasis,clinical stage,clinical manifestations,imaging findings,and treatment methods,to study the clinicopathological characteristics of PSCCB.Patients with PSCCB were followed up to analyze their prognosis and related influencing factors.In addition,data of 158 patients diagnosed with PSCCB from December 2009 to December 2018 were extracted from the SEER database using SEER*Stat 8.3.9 software to further analyze the clinicopathological features and prognostic factors.Result:(1)The First Affiliated Hospital of Zhengzhou University and People’s Hospital of Zhengzhou University:The primary symptoms of PSCCB were internal mammary mass in 37 cases(80.4%),eczema of the nipple in 1 case(2.2%),and mammary abscess in 8 cases(17.4%),among which 7 patients had mastitis symptoms such as breast redness and skin ulceration.The clinical characteristics of PSCCB are similar to those of triple negative invasive ductal carcinoma of breast,with a median age of older(49.5 vs 49.0 years),a high proportion of primary mass with a maximum diameter of 20-50mm(60.9%vs 61.2%),and no distant metastasis(93.5%vs 3.8%)during diagnosis and treatment.The proportion of clinical stage ii was higher(60.9%vs 71.2%).Compared with triple negative invasive ductal carcinoma,PSCCB was associated with less axillary lymph node metastasis(32.6%vs 53.8%),and the difference was statistically significant(P<0.05).ER and PR of PSCCB were negative,Her-2 was positive in 6 patients(13.0%),Ki-67 was>30%(82.6%)and EGFR was positive in most patients(82.6%).Compared with triple negative invasive ductal carcinoma.CK5/6,P53 and CD31 were more positive(97.8%vs 51.2%,78.3%vs 57.5,73.9%vs 63.5%),and the differences were statistically significant(P<0.05).Survival analysis showed that overall survival(OS)and disease free survival(DFS)were similar in the two groups,and PSCCB was slightly worse than that of invasive ductal carcinoma of the triple negative breast(5-year OS:53.6%vs 57.6%,5-year DFS:46.1%vs 47.9%).Univariate survival analysis showed that the factors significantly correlated with the 5-year OS of PSCCB patients were the maximum diameter of primary mass,axillary lymph node metastasis,distant metastasis,clinical stage,chemotherapy regimen,EGFR expression and CD31 expression.The factors that were significantly correlated with 5-year DFS of PSCCB patients included maximum size of primary mass,distant metastasis,clinical stage,chemotherapy regimen,EGFR expression and CD31 expression.Multivariate survival analysis indicated that the independent prognostic factors of 5-year OS for PSCCB patients included the maximum size of primary mass,distant metastasis,clinical stage and chemotherapy regimen,while the independent prognostic factors of 5-year DFS included distant metastasis and chemotherapy regimen.Most patients with PSCCB received modified radical mastectomy for breast cancer(73.9%),and very few patients received breast conserving surgery and sentinel lymph node biopsy(4.3%).All patients with PSCCB received adjuvant chemotherapy,and there were 27 cases(58.7%)with platinum chemotherapy drugs in their chemotherapy regimen,and 19 cases(41.3%)without platinum chemotherapy drugs.Stratified multifactor survival analysis was conducted for chemotherapy regimens in patients with PSCCB of different clinical stages,and it was found that chemotherapy regimens were independent factors affecting 5-year OS in stage ii PSCCB patients,and the prognosis was that platinum-containing regimens were better than platinum-free regimens.(2)SEER database:Among 158 patients with PSCCB included,the median age was 65.0 years.Most of the patients were over 50 years old(83.5%),the maximum diameter of the primary mass was between 20mm and 50mm(41.8%),no lymph node metastasis(65.2%),no distant metastasis(86.1%),and clinical stage II(41.8%).There were 123 patients(77.8%)with negative ER expression.A total of 141 patients(89.2%)had negative expression of PR,and 149 patients(94.3%)had negative expression of HER-2.The 5-year OS of PSCCB patients was 58.2%,and the median survival time was 42.0 months.Clinical stage was an independent factor affecting 5-year OS of PSCCB patients.Conclusion:PSCCB is rare,highly invasive and has a relatively poor prognosis.Its clinicopathological features are similar to triple negative invasive ductal carcinoma,which can be referred to for diagnosis and treatment.CD31 may be used as a new biomarker in combination with CK5/6,P53 and EGFR.The maximum size of the primary mass,distant metastasis,clinical stage and chemotherapy plan are closely related to the prognosis of PSCCB,and the application of chemotherapy plan containing platinum drugs can effectively improve the prognosis of PSCCB patients.