Local recurrence rates of breast cancer if treated with chemotherapy before or after surgery

This paper investigates which approach provides longer recurrence free survival time after breast conserving surgery – pre- or post-operative chemotherapy. 

Breast conserving surgery (lumpectomy) or BCS is surgery to remove the cancer and a section of healthy tissue around it. Women who choose this treatment option keep their breast (as opposed mastectomy in which the entire breast is removed), but they usually must have radiation therapy after surgery. Both procedures are viable treatment options for women with a confined breast cancer. Some women are treated with chemotherapy in addition to BCS and radiation, in order to eradicate the cancer completely and reduce the risk of the cancer reoccurring. 

2,988 patients were included in this study (treated from January 1987 to December 2005). All patients had external beam targeted radiotherapy after surgery. 2,331 women (78%) had chemotherapy after BCS (called adjuvant chemotherapy), whereas 652 (22%) were treated prior to surgery (called neoadjuvant chemotherapy). 

Results showed that neoadjuvant chemotherapy managed to decrease the clinical stage of tumors, from 2/3 to 0/1 in 313 out of 607 (52%) patients. This result was expected, it is this lowering in tumor grade that has increased the number of patients who can have BCS instead of a mastectomy. 

The 5 and 10-year survival rates without local recurrences (percentage of patients alive after a certain period of time, without the cancer reoccurring) were 97% and 94% in patients who had adjuvant chemotherapy, and 93% and 90% in those who received neoadjuvant chemotherapy. This difference was statistically significant in favor of adjuvant chemotherapy. However, when results were looked at more closely and tumor factors such as hormone receptors, nuclear grade, HER2 expression and clinical grade were considered, no substantial differences in the rate of local recurrence between treatment groups were noted.

The paper concludes that local recurrence is linked to the biology of the tumor rather than to the order in which treatments are given. They found no difference in recurrence-free survival rates between patients who received pre- or post-operative chemotherapy.

These findings are limited as the medications used for chemotherapy regimens varied between patients, and this variation was not taken into account.