Overexpression of C35 in breast carcinomas is associated with tumor progression and lymphnode metastasis

To investigate C35 protein expression in breast carcinoma and to investigate its clinicopathological significance, a total of 68 cases of breast carcinoma and 20 cases of normal breast tissue samples were obtained from the clinic. Protein expression of C35, ER, PR and HER-2 were determined using immunohistochemistry. The correlations between C35 expression and clinicopathological parameters were analyzed on the basis of individual clinicopathologic records. Overexpression of C35 was detected in 56 of 68 (82.35%) breast carcinoma samples and only 3 of 20 (15%) normal breast tissue samples, and frequency of C35 expression was significantly associated with clinical Tumor Node Metastasis staging and Scarff-Bloom-Richardson grade (p < 0.05), but was not related to patients age, menstrual status and tumor diameter. C35 expression was positively related with the expression of HER-2 (r = 0.207), whereas negatively related with the expression of ER and PR. Further, C35 was prevalent in all four molecular subtypes of breast carcinoma with no significant difference of expression frequency. However, they have significant differences in lymphatic metastasis cases compared to the non-metastasis cases (p < 0.05). Since C35 protein was extensively expressed in all stages of breast carcinoma, and was closely associated with tumor progression and lymph node metastasis, it might be used as a reliable biomarker or therapeutic target for diagnosis and treatment.