Interrelationships Between Ki67, HER2/neu, p53, ER, and PR Status and Their Associations With Tumor Grade and Lymph Node Involvement in Breast Carcinoma Subtypes: Retrospective-Observational Analytical Study.

Various predictive and prognostic factors could affect breast carcinoma behavior, but to date no definitive correlation has been established between them and breast carcinoma subtypes. The present study was conducted to examine the interrelationships of these predictive and prognostic factors as well as their effects on breast carcinoma subtypes.The archives of all patients with breast carcinoma (from 2008 to 2014) were studied. Patients' data were extracted using a checklist that included age, histology type, size and grade of tumor, lymph node involvement, estrogen receptor (ER) and progesterone receptor (PR) status, along with the overexpression of human epidermal growth factor receptor (HER2/neu) and the rate of Ki67 and p53 mutations. All data were analyzed by SPSS-17 software with χ and Fisher exact tests, as well as the least significant difference pairwise comparison test.A total of 566 patients' records were included in this study. The mean age of patients was 50 ± 12.9 with an age range of 17 to 98 years. A meaningful correlation was found between age and the type of tumor (P = 0.001). Infiltrating lobular carcinoma had a higher ER positivity between groups (85.7%), whereas noninvasive carcinomas had a higher PR positivity (67%). In addition, a meaningful correlation was detected between the type and grade of tumor (P = 0.001). No meaningful relationship was observed between the type of tumor and HER2/neu overexpression and number of lymph nodes involved. Between the groups, medullary carcinoma had the highest Ki67 index (P = 0.007). Meaningful correlation was found between the grade of tumor and lymph node involvement (P = 0.005) and also with HER2/neu overexpression (P = 0.002). Higher grades had greater positivity in Ki67 index and p53 mutation rates (P = 0.002, P = 0.01). HER2/neu positive tumors had a higher Ki67 index (P = 0.03).Higher Ki67 index tumors showed more HER2/neu overexpression, larger size, and more lymph node involvement compared with other types and maybe considered aggressive. Moreover, in young patients with breast carcinoma, the rates of Ki67 with the overexpression of HER2/neu and p53 mutations are higher, and it shows a more aggressive behavior than other tumors assessed in this age group.