Differences in Response and Surgical Management with Neoadjuvant Chemotherapy in Invasive Lobular Versus Ductal Breast Cancer

Abstract

BackgroundThis study was conducted to determine the impact of neoadjuvant chemotherapy (NAC) on the likelihood of breast-conserving surgery (BCS) performed for patients with invasive lobular breast carcinoma (ILC) and invasive ductal carcinoma (IDC).MethodsFemale patients with a diagnosis of ILC or IDC in The Netherlands between July 2008 and December 2012 were identified through the population-based Netherlands Cancer Registry.ResultsA total of 466 ILC patients received NAC compared with 3622 IDC patients. Downstaging by NAC was seen in 49.7 % of the patients with ILC and in 69.6 % of the patients with IDC, and a pathologic complete response (pCR) was observed in 4.9 and 20.2 % of these patients, respectively (P < 0.0001). Breast-conserving surgery was performed for 24.4 % of the patients with ILC receiving NAC versus 39.4 % of the patients with IDC. In the ILC group, 8.2 % of the patients needed surgical reinterventions after BCS due to tumor-positive resection margins compared with 3.4 % of the patients with IDC (P < 0.0001). Lobular histology was independently associated with a higher mastectomy rate (odds ratio 1.91; 95 % confidence interval 1.49–2.44). Among the patients with clinical T2 and T3 disease, BCS was achieved more often when NAC was administered in ILC as well as IDC.ConclusionThe patients with ILC receiving NAC were less likely to experience a pCR and less likely to undergo BCS than the patients with IDC. With regard to BCS, the impact of NAC for ILC patients was lower than for patients receiving surgery without NAC. However, despite the high number to treating in order to achieve BCS, a small subset of ILC patients, especially cT2 and cT3 patients, still may benefit from NAC.

Unifocal Invasive Lobular Carcinoma: Tumor Size Concordance Between Preoperative Ultrasound Imaging and Postoperative Pathology

“…Receptor status 25,26 in conjunction with extent of disease 24 is important when considering neoadjuvant therapy for ILCs, especially when breast conservation is considered 24,27–29 . Breast ultrasound is a widely available modality and can be used as a complement to further characterize lesions.…”

“…This is important in the context of neoadjuvant therapy. Among patients who undergo neoadjuvant chemotherapy, pathologic complete response rate is lower with ILCs than ductal cancers 24,25 and is dependent on receptor status 25,26 . However, neoadjuvant chemotherapy, in particular for clinically-assessed T2 and T3 ILCs, can be of benefit in facilitating breast conserving surgery 24 .…”

“…Among patients who undergo neoadjuvant chemotherapy, pathologic complete response rate is lower with ILCs than ductal cancers 24,25 and is dependent on receptor status 25,26 . However, neoadjuvant chemotherapy, in particular for clinically-assessed T2 and T3 ILCs, can be of benefit in facilitating breast conserving surgery 24 . Accurate measurement of tumor size in combination with receptor status 25,26 can help in identifying subjects that are likely to benefit from breast conservation following neoadjuvant chemotherapy.…”

Standard Pathologic Features Can Be Used to Identify a Subset of Estrogen Receptor-Positive, HER2 Negative Patients Likely to Benefit from Neoadjuvant Chemotherapy

“…4,10–12 We were able to identify whether patients required a mastectomy or were candidates for BCS pre-treatment by surgeon documentation both pre- and post-NAC, and excluded those who had a priori contraindications to BCS, allowing us to more accurately analyze the rate of downstaging and potential benefit of NAC.…”

“…10–12 The lower rates of pCR translate into lower rates of BCS after NAC than seen with invasive ductal carcinoma (IDC) 9–12 , but whether these differences are the result of histology per se or other features, such as grade and receptor status, has been questioned. 13,14 …”