Faculty Bibliography

BACKGROUND: Breast conservation therapy (BCT) with sentinel lymph node (SLN) biopsy is a well-established standard of care for primary operable breast cancer; 5-10% of BCT patients will develop local recurrence (LR). The question then arises: How best to manage the axilla in the setting of LR after previous BCT and SLN biopsy or axillary dissection (ALND)? METHODS: Between 9/96 and 12/04, 117 reoperative SLN were performed for LR after BCT and either SLN biopsy or ALND more than 6 months previously. Because of wide variation in the number of nodes removed at the initial procedure, validation by backup ALND was not feasible in all cases. RESULTS: Reoperative SLN was successful in 64/117 (55%) patients. SLNs were identified by isotope and dye in 28/64 (44%); isotope only in 29/64 (45%); dye only in 4/64 (6%); 3/64 (5%) unknown. Positive reoperative SLN were found in 10/64 (16%) successful cases. Among 54/64 (84%) patients with negative reoperative SLNs, 23 (43%) had additional non-SLN removed concurrently: these were negative in 21/23 cases (91%). In 2/23 (9%), reoperative SLN were falsely negative: one with a positive intramammary node, and the other with a positive non-SLN palpated at surgery. Success of reoperative SLN was inversely related to number of nodes removed previously, and was more likely to be successful after a previous SLN biopsy than a previous ALND (74% vs. 38%, P = 0.0002). Non-axillary drainage was identified by lymphoscintigraphy significantly more often in reoperative SLN than in primary SLN biopsy (30% vs. 6%, P < 0.0001). There were no local or axillary recurrences at a mean follow up of 2.2 years; 6 patients developed systemic recurrence. CONCLUSIONS: Reoperative SLN biopsy is feasible in the setting of LR after previous BCT/axillary surgery and deserves further study in this increasingly common clinical scenario. The added benefit of lymphoscintigraphy in identifying sites of non-axillary drainage may be greater in the setting of reoperative SLN than for the initial SLN procedure.

BACKGROUND: In breast-conserving surgery (BCS), the method of margin assessment and the definition of a negative margin vary widely. The purpose of this study was to compare the incidence of positive margins and rates of reexcision between two methods of margin assessment at a single institution. STUDY DESIGN: In July 2004, our protocol for margin evaluation changed from perpendicular inked margins (Group A, n=263) to tangential shaved margins (Group B, n=261). In Group A, margins were classified as positive, close, and negative. Margins designated as "close" were further defined as: < or = 1 mm, < or = 2 mm, and < or =3 mm. In Group B, shaved margins (by definition 2 to 3 mm) were reported as positive or negative. RESULTS: The rate of reported "positive" margins was significantly higher in Group B: 127 of 261 (49%) versus 42 of 263 (16%), p < 0.001. But when patients with "positive, close, or both" kinds of margins were combined in Group A, there was no significant difference between the two techniques. Although the shaved margin was 2- to 3-mm thick, the rate of reexcision in Group B was significantly higher when compared with that in patients with "positive, close, or both" < or =3 mm margins in Group A (75% versus 52%, p < 0.001). The likelihood of finding residual disease remained the same (27% versus 32%, p=NS). CONCLUSIONS: The tangential shaved-margin technique results in a higher proportion of reported positive margins and limits the ability of the surgeon to discriminate among patients with close margins, resulting in a higher rate of reexcision. The fact that many, but not all, patients with positive or close margins in both groups underwent reexcision emphasizes the role of surgical judgment in this setting. Longer followup is required to determine equivalency in rates of local recurrence between these two methods of margin assessment.

OBJECTIVE: To compare sentinel lymph node (SLN)-positive breast cancer patients who had completion axillary dissection (ALND) with those who did not, with particular attention to clinicopathologic features, nomogram scores, rates of axillary local recurrence (LR), and changes in treatment pattern over time. BACKGROUND: While conventional treatment of SLN-positive patients is to perform ALND, there may be a low-risk subgroup of SLN-positive patients in whom ALND is not required. A multivariate nomogram that predicts the likelihood of residual axillary disease may assist in identifying this group. METHODS: Among 1960 consecutive SLN-positive patients (1997-2004), 1673 (85%) had ALND ("SLN+/ALND") and 287 (15%) did not ("SLN+/no ALND"). We compare in detail the clinicopathologic features, nomogram scores, and rates of axillary LR between groups. RESULTS: Compared with the SLN+/ALND group, patients with SLN+/no ALND were older, had more favorable tumors, were more likely to have breast conservation, had a lower median predicted risk of residual axillary node metastases (9% vs. 37%, P < 0.001), and had a marginally higher rate of axillary LR (2% vs. 0.4%, P = 0.004) at 23 to 30 months' follow-up; half of all axillary LR in SLN+/no ALND patients were coincident with other local or distant sites. For patients in whom intraoperative frozen section was either negative or not done, the rate of completion ALND declined from 79% in 1997 to 62% in 2003 to 2004 but varied widely by surgeon, ranging from 37% to 100%. For 10 of 10 evaluable surgeons, the median nomogram scores in the SLN+/no ALND group were

PMCID:1877014

PMID: 17435554

ISSN: 0003-4932

CID: 2004192