Expression of survivin and its clinicopathological correlations in invasive ductal carcinoma of the breast

INTRODUCTION: Survivin is a 16.5-kDa intracellular protein that inhibits apoptosis and regulates cell division, and belongs to the inhibitors of apoptosis gene family. It appears to have an important role in regulating apoptosis at the cell cycle checkpoints. Survivin has been found to have a differential distribution in cancer compared to normal tissue, as it is over-expressed in malignant tumours.
METHODS: In addition to the demographical analysis of the disease, data from 382 women with invasive ductal carcinoma of the breast were collected from three hospitals in Northeast Malaysia, and analysed for survivin expression by immunohistochemistry.
RESULTS: Invasive ductal carcinoma of the breast was found to be the most prevalent breast cancer type. Survivin was detected in 260 (68.1 percent) study cases. In addition, significant correlations have been shown between survivin expression on one hand, and tumour size and lymph node involvement on the other hand (p-value is less than 0.05). However, no significant correlations were found with other clinicopathological factors, such as tumour histological grade, tumour side, oestrogen and progesterone receptors. Nuclear expression of survivin was detected in 16.5 percent of the study cases, cytoplasmic expression was detected in 24.1 percent, and 27.5 percent of the cases expressed survivin in both nuclear and cytoplasmic locations simultaneously. The subcellular localisation of survivin was significantly correlated (p is less than 0.001) with the lymph node involvement indicating its value in predicting the aggressiveness of tumour cells, since it increases the resistance to apoptosis and promotes cell proliferation.
CONCLUSION: This is the fi rst known report on survivin expression in cancer in West Malaysia and Southeast Asia. It emphasises the importance of the detection of survivin in breast cancer to aid in diagnosis, confirm malignancy, and to assess the disease progress and response to therapy.