Chemotherapy before surgery; is there a different in outcome between different types of breast cancer?

The authors aimed to evaluate if the outcomes of surgery following chemotherapy are different based on the focality of breast cancer tumors. 

Breast cancer can be characterised as 'unifocal', 'multifocal and 'multicentric'. This refers to the number of areas in which the cancer can be found (focality); unifocal being one tumor, multifocal being more than one tumor that originated from the same original tumor and multicentric being more than one tumor separated by normal breast tissue.

Surgical treatment for breast cancer can vary depending on the type of focality and can include breast conserving surgery (breast remains intact; only tumor and some surrounding tissue is removed) and mastectomy (removal of entire breast). Previously, breast conserving surgeries were not recommended for multifocal tumors. However modern neoadjuvant chemotherapy (preliminary treatment to shrink tumor before further treatment i.e. surgery) increases treatment success.

The aim of this study was to assess the impact of neoadjuvant chemotherapy and tumor focality on the success of breast cancer surgery.

A total of 6,134 women were evaluated;  4,733 had unifocal cancer, 820 had multifocal cancer and 581 had multicentric cancer.Chemotherapy followed by breast conservation surgery was performed on 3,217 patients (71.6% of the unifocal patients, 58.8% of the multifocal patients and 30% of the multicentric patients).

The results showed a 88.2% overall survival rate for those with unifocal disease, 89.5% for tor those with multifocal disease and 84.7% for those with mutlicentric tumors. However, in all patients who showed a good response to initial chemotherapy, there was no difference in survival outcome between groups after surgery. 

More patients who had unifocal disease were alive without disease after three years (81.3%) compared those with multicentric tumors (75.6%). There was no difference in survival without disease for those with unifocal compared to those with multifocal disease. 

The authors concluded that chemotherapy followed by breast conservation surgery is a valuable option for multifocal and multicentric breast cancers.