Many Women whose Tumors Disappear after Chemotherapy Have MastectomiesMany women with breast cancer whose tumors disappear after presurgical chemotherapy have a mastectomy instead of breast-conserving surgery, according to a re-analysis of data from the NeoALTTO trial. The results were presented September 30 at the 2012 European Society for Medical Oncology Congress (ESMO).
In the phase III trial, investigators randomly assigned women with HER2-positive breast cancer to receive trastuzumab, lapatinib, or both drugs for a total of 18 weeks prior to surgery. (Both drugs target the HER2 receptor.) After the first 6 weeks, paclitaxel chemotherapy was added to the anti-HER2 treatments.
In 160 of 429 women, the tumors disappeared (a pathologic complete response). But whether a woman had a pathologic complete response did not influence the type of surgery she had later. Although women receiving all three drugs were up to twice as likely to have their tumors disappear as women who received only a single anti-HER2 drug plus paclitaxel, they were no more likely to have breast-conserving surgery than a mastectomy.
Instead, the ultimate choice of surgery type was more strongly influenced by the characteristics of the tumor before chemotherapy, including the initial tumor size and whether the tumor expressed the estrogen receptor, as well as the type of surgery originally planned and whether the cancer was multifocal or multicentric.
One of the main goals of presurgical (neoadjuvant) chemotherapy is to “downstage” larger tumors to allow less-aggressive surgery. Therefore, “there is a need for a clear consensus on the role of breast-conserving surgery, especially in patients who respond to neoadjuvant therapy,” said lead investigator Dr. Carmen Criscitiello, of the European Institute of Oncology in Milan, Italy, at an ESMO press conference.
“This will ultimately translate…into improved breast-conservation rates, [and] could spare more women from receiving radical treatment like mastectomy,” she concluded.