Breast cancer recurrence; is breast conserving therapy still relevant?

This paper studied locoregional recurrences (return of cancer to the same area) in breast cancer. They compared mastectomy (removal of entire breast) to breast conserving therapy (removal of some breast tissue). 

Breast conserving therapy involves removing part of the breast plus radiation. After breast-conserving therapy, about 10% of patients have a locoregional recurrence of breast cancer within 10 years. A young age, absence of hormone receptors on cancer cells and large tumour size increases the risk of cancer returning. Treatment for local recurrence (return of cancer) is usually mastectomy, however, a second breast conserving therapy my also be possible. 

380 patients with at least one breast cancer recurrence (return) were studied. All patients either underwent breast conserving therapy (65%) or mastectomy (35%). Some patients lso underwent hormone therapy (33.5%) or chemotherapy (37.5%).

65% of patients had one recurrence, 24.7% of patients had two recurrences and 10.3% of patients had 3 recurrences. Overall, patients survived for an average 10.1 years. The average time from the first diagnosis of cancer to the first recurrence was 5.7 years.

The authors also studied the change in hormone receptors (proteins that can be found on cancer cells) from first diagnosis to recurrence. A change in hormone receptor affected survival. Patients who changed from an absent estrogen receptor to a present estrogen receptor at first recurrence had a longer survival time than those whose estrogen receptor remained absent or changed from present to absent. Patients who continued to have progesterone receptor present had the longest survival compared to patients who continued to have absent progesterone receptor.

The authors found no associations between characteristics of the tumour at the first recurrence and the number of further recurrences. At 5 years after the first recurrence, 100% of patients receiving breast conserving surgery survived and 91.2% of patients receiving mastectomy survived.  

The authors concluded that since hormone receptors influence survival, the presence or absence of hormone receptors should be determined at each recurrence of cancer. Results suggest that having breast conserving surgery is comparable to a mastectomy at first recurrence.