Achieving a pathologic complete response to neoadjuvant chemotherapy does not always reduce the aggressiveness of breast cancer surgery, according to an analysis of the NeoALLTO trial presented at the 2012 European Society for Medical Oncology (ESMO) Congress in Vienna.1
Carmen Criscitiello, MD, of the European Institute of Oncology in Milan, Italy, and colleagues determined which factors influenced the type of surgery (mastectomy or lumpectomy) offered to the 429 patients with HER2-positive breast cancer who underwent breast surgery after receiving neoadjuvant therapy within the NeoALTTO trial.
“Apparently, the final decision on the type of surgery was mainly based on characteristics observed before therapy,” Dr. Criscitiello noted. “Surgeons and medical oncologists should focus, however, on the characteristics observed after treatment, with discussions occurring in a multidisciplinary way before final decisions are made.”
Findings from NeoALLTO
NeoALLTO investigators previously reported that the combination of paclitaxel, lapatinib (Tyekrb), and trastuzumab (Herceptin) significantly increased the pathologic complete response rate compared to paclitaxel combined with either drug alone.2 Several international expert panels have recommended that the rate of breast-conserving surgery should increase in patients who respond well to neoadjuvant treatment, as was seen in this trial, Dr. Criscitiello said.
But while the pathologic complete response rate was 51.3% with the dual HER2 blockade, breast-conserving surgery was performed on only 41.4% of women. Regardless of which treatment the women received, breast-conserving surgery rates hovered around 40%, Dr. Criscitiello reported.
“The experimental treatment with paclitaxel plus lapatinib and trastuzumab within the NeoALTTO trial nearly doubled the rate of pathologic complete response compared to treatment with paclitaxel combined with either drug alone,” she said. “However, this successful result did not translate into a higher rate of breast-conserving surgery.”
Factors Influencing Type of Surgery
Several factors were found to be related to choice of surgery after systemic therapy, most notably the surgical plan at diagnosis. If breast-conserving surgery was planned in advance, 74% underwent it. On the other hand, 30% of patients initially considered inoperable or requiring mastectomy had breast-conserving surgery. Larger tumor size at diagnosis also influenced the type of planned surgery.
“Indeed, we saw that tumor characteristics prior to neoadjuvant therapy play a main role in deciding the type of surgery, irrespective of the response to given therapies,” Dr. Criscitiello said. “One of the goals of the neoadjuvant therapy concerns increasing the rate of breast conservation, but this goal is clearly not achieved if the type of surgery is chosen according to baseline characteristics.”
Geographic region influenced the choice of treatment at baseline, with breast-conserving surgery significantly less common in developing countries compared to developed countries: 32.1% vs 53.2% (P = .006). This probably represents the lack of radiotherapy in poorer countries. Mastectomy is likely the appropriate choice under these circumstances, several breast cancer specialists suggested at the meeting.
Several baseline factors influenced the choice of surgery, with conservative surgery significantly less likely in the case of tumors that were larger than 5 cm, demonstrated multicentricity or multifocality, or were estrogen receptor–negative.
“This study highlights a negative attitude that may deny a large fraction of women the chance of preserving their breasts, with no clinical reasons that justify this decision,” Dr. Criscitiello concluded. ■
Disclosure: Dr. Criscitiello reported no potential conflicts of interest.
1. Criscitiello C, Azim HA, Agbor-Tarh D, et al: The discrepancy between high pathological complete response rate and low breast conserving surgery following neoadjuvant therapy: Analysis from the NeoALLTO trial (BIG 1-06). 2012 ESMO Congress. Abstract 2470. Presented September 30, 2012.
2. Baselga J, Bradbury I, Eidtmann H, et al: Lapatinib with trastuzumab for HER2-positive early breast cancer (NeoALTTO): A randomised, open-label, multicentre, phase 3 trial. Lancet 379:633-640, 2012.