Biopsy of breast tumors may spread cancer cells through the acute inflammatory response
Biopsy is the next logical step for tumors screened by mammography, but a study just published in the journal Breast Cancer Research and Treatment demonstrates that it is possible for tumor cells to be spread by the acute inflammatory response to the biopsy procedure. Happily, the authors also show that anti-inflammatory treatment prior to the biopsy can protect against metastasis. The authors state:
"Development of metastasis in peripheral tissues is a major problem in the fight to cure breast cancer. Although it is becoming evident that chronic inflammation can contribute to tumor progression and metastasis, the effect of acute inflammation in primary tumor is less known. Using mouse models for breast cancer here we show that biopsy of mammary tumors increases the frequency of lung metastases."
The specific mechanism they examined involves the systemic increase in the pro-inflammatory cytokines including interleukin-6 (IL-6):
"This effect is associated with the recruitment of inflammatory cells to the lung and elevated levels of certain cytokines such as IL-6 in the lung airways."
Fortunately, there is a silver lining:
"Antiinflammatory treatment prior to and after the biopsy reduces the development of metastases triggered by the biopsy. In addition, while lack of IL-6 does not affect primary tumor development, it protects from increasing number of metastases upon biopsy."
Of course there are a number of limitations to this study. But the role of inflammation in the development and spread of cancer is so important, and anti-inflammatory prophylaxis before and after biopsy so benign, this may offer a massive opportunity to be "safe rather than sorry". The authors conclude:
"Thus, our studies show that in addition to chronic inflammation, acute immune response caused by invasive procedures in the primary tumor may cause an increased risk on peripheral metastases, but the risk could be decreased by anti-inflammatory treatments."