J. David Beatty

The Christante et al article describes the effect of IRB and postmastectomy chest wall irradiation on postmastectomy complication rates. For patients with no re

This study reports the value of the tumor markers estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in predicting the response of breast cancer to neoadjuvant chemotherapy. A community cancer center prospectively maintained breast cancer database containing over 8,000 patient records was used. Since 1989, 464 patients were treated with neoadjuvant chemotherapy followed by surgical resection and were tested for ER and PR. Estrogen receptor and/or PR positive patients were considered hormone receptor (HR) positive. Human epidermal growth factor receptor 2 status was available on 368 patients. Total, breast, and nodal pathologic complete response (pCR) rates, recurrence, and overall survival were assessed. Total and breast pCR rates were higher in HR negative (HR-) patients (26% and 32%, respectively) than in HR positive (HR+) patients (4% and 7%, respectively; p < 0.001). Compared to HR+ patients, HR- patients had higher recurrence rates (38% versus 22%; p < 0.001), a shorter time to recurrence (1.28 versus 2.14 years; p < 0.001), and decreased overall survival (67% versus 81%; p < 0.001). Human epidermal growth factor receptor 2 positive patients treated with neoadjuvant trastuzumab (NAT) demonstrated higher total pCR (34% versus 13%; p = 0.008), breast pCR (37% versus 17%; p = 0.02), and nodal pCR rates (47% versus 23%; p = 0.05) compared to HER2+ patients not treated with NAT. Furthermore, HER2+ patients who received NAT had lower recurrence rates (5% versus 42%; p < 0.001) and increased overall survival (97% versus 68%; p < 0.001). In conclusion, breast cancer HR status is predictive of total and breast pCR rates after neoadjuvant chemotherapy. Although HR- patients derive greater benefit from neoadjuvant chemotherapy in terms of pathologic response, they have worse outcomes in terms of recurrence and survival. Hormone receptor positive patients demonstrate significantly less response to neoadjuvant chemotherapy, but significantly better overall outcome. For both HR- and HR+, addition of NAT for HER2+ tumors results in both a superior response and outcome.

In 2003, the American Joint Committee on Cancer (AJCC) initiated the 6th edition staging criteria, including pN0(i+) and pN1mi categories for breast cancer. However, the clinical significance of these categories is debated in the literature. A prospective registry was used to identify patients staged with sentinel lymph node (SLN) biopsy. SLN evaluation included routine serial sectioning and immunohistochemical stains. SLN biopsies performed before January 2003 were restaged according to the AJCC's 6th edition criteria. Of 954 SLN biopsies identified, on review, 491 N0i-, 86 N0i+, 73 N1mi, 146 N1a, 29 N2a, and 11 N3a patients were available for analysis with a median follow-up of 45.4 months. Significant prognostic and therapeutic differences existed between the groups. Differences in overall survival (OS) and recurrence-free survival (RFS) were only noted when the size of the metastases reached the N1a level. There were no statistically significant differences in OS or RFS between N0(i-) and N0(i+) or N1mi disease. Cases that were N0(i+) or N1mi were more likely to have other poor prognostic factors and to receive more aggressive therapy. SLN biopsy allows a more sensitive evaluation of lymph nodes for metastatic cells. This has led to the increased identification of very small axillary metastases. While the new microstaging categories are not yet clearly associated with a significantly decreased OS or DFS in this series, they are associated with other poor prognostic factors and more local/regional and systemic therapy. Further analysis of the microstaging categories is needed.

In breast cancer treatment, intraoperative sentinel lymph node (SLN) evaluation is used to identify patients who may potentially benefit from immediate completion of axillary lymph node dissection. Prospectively collected breast cancer registry data identified 516 SLN biopsies between January 2003 and December 2005. Intraoperative evaluation (IE) of the SLNs was performed in 479 axillae. Final pathology by hematoxylin and eosin and, for negative nodes, by immunohistochemical stains was compared with the IE result. The effect of IE and final pathology on surgical treatment was examined. The sensitivities for IE of N0(i+) (n = 39), N1mi (n = 41), and N1a–3a (n = 89) metastases were 0%, 5%, and 63%, respectively. The specificity was 99.7%. IE identified 57 (44%) of SLN-positive (N1mi and N1a–3a) axillae, thus resulting in synchronous axillary lymph node dissection for those patients. Reoperation for false-negative IEs (N1mi or N1a–3a with negative IE) occurred in only 27 axillae (39%). IE of SLNs has adequate sensitivity and excellent specificity. In addition to allowing patients to benefit from synchronous surgery, IE helped patients to receive care in concordance with recommended practice guidelines. The false-negative IE of SLNs highlights uncertainty with the clinical significance of axillary nodal staging when only small amounts of metastatic disease are identified in the axilla.