Is there a link between tumor budding and survival from breast cancer?

The authors aimed to determine whether or not there is a link between tumor budding, the environment of a tumor and prognosis (outlook) and survival from breast cancer.

Tumor budding refers to the 'clustering' of up to 5 cancer cells together to create a tumor 'bud'. Tumor budding is thought to be an early step in cancer metastasis (the tumor spreads to other organs).

Previous studies suggest that tumor budding can be a prediction to prognosis and survival in many types of cancer. The environment of tumor budding (such as number of blood vessels, level of inflammation) may also have an effect on tumor budding. It is unknown, however, how much of an impact tumor budding and the tumor environment has on overall survival in breats cancer.

The aim of this study was to determine the effect of tumor budding and tumor environment on breast cancer survival.

A total of 474 women were evaluated for this study. 60% of these women had a small tumor, 69% had estrogen receptor positive (ER+, dependent on estrogen for growth) tumors  while 61% had progesterone receptor positive (PR+, dependent on progesterone for growth) tumors. A high tumor budding was identified in 35% of the patients.

Overall, tumor budding was associated with reduced patient survival time. The average cancer-specific survival time (time until death due to cancer) in women with high tumor budding was 136 months compared to 159 months in those with low tumor budding.

High-budding tumors were also significantly associated with ER+ tumors and cancer spread to the lymph vessels (channels that carry nutrients in and waste out of breast tissue). Patients with high budding were two times less likely to survive as long as those with low tumor budding. Patients with high tumor budding also had a weaker inflammatory response (the immune system response to foreign cells in our body). 

The authors confirmed that tumor budding predicted survival in breast cancer patients.