Does Chemotherapy before breast cancer surgery fuel metastasis?

The jury is still out on whether chemotherapy before breast cancer surgery fuels metastasis. Studies conducted thus far have been inconclusive, and the results have been mixed.

A literature review by the National Institutes of Health (NIH) looked at sixteen studies regarding this topic across different metastatic subtypes, treatments, and follow-up periods to assess if chemotherapy before surgical treatment increases metastases. In most cases they found no association between preoperative chemotherapy and increased risk of distant metastases or mortality rates after 5 years; however, there was a statistically significant increase in locoregional recurrence when comparing neoadjuvant therapy with local surgery alone in selected subgroups.

Furthermore, additional research suggests that although distant metastasis does not seem to be impacted by preoperative chemotherapies, certain tumor characteristics (e.g., those involving estrogen receptor [ER] positive/HER2 negative breast cancers) may benefit from them due to their ability to reduce locoregional recurrence rates without increasing the risk for distant relapse or mortality once combined with other systemic treatments such as hormone therapy or trastuzumab-based regimens.

In conclusion, although there are some indications that preoperative chemotherapy can lead to increased risk of locoregional recurrences in patients with specific tumor characteristics, more research is needed before concluding that it will substantially increase a patient's risk for developing distal relapse and mortality postoperatively compared with surgery alone - making decisions concerning preoperative chemotherapeutic use still subject to much debate among medical practitioners today.