Abstract P2-01-04: Use of axillary ultrasound impacts outcome of node positive breast cancer patients

Background The Z0011 trial initiated a paradigm shift in the treatment of axillary node positive breast cancer patients. Treatment strategy, however, starts with the information gathered by the diagnostic axillary work up. This can either be done by sentinel lymph node biopsy (SLNB) or ultrasound guided lymph node biopsy (UGLNB). We examined whether there are relevant clinical and prognostic differences between patients found node positive by these two diagnostic selection processes.

Methods Patients diagnosed with invasive breast cancer in the Netherlands between January 2000 and December 2013 were studied. Patients with no clinically palpable lymphadenopathy (cN0) and node-positive disease after an axillary lymph node dissection (ALND) were included. Patients with stage IV breast cancer, with clinical stage T3-T4 breast tumor according to the TNM-classification, those treated within the neo-adjuvant setting, patients with palpable axillary nodes (cN≥1) and patients who did not undergo an ALND were excluded.

Results A total of 14,730 patients fulfilled the inclusion criteria, of whom 9,448 were included in the SLNB group and 5,282 in the UGLNB group. Patients in the UGLNB group were older at diagnosis (p<0.001), had larger tumors (p<0.001), a higher tumor grade (p=0.001), and were more likely to have a negative hormonal receptor status (p<0.001) and to undergo a mastectomy (p<0.001). Patients in the UGLNB group were also more likely to have ≥3 positive axillary lymph nodes (p<0.001) and, after adjustment for these differences, had a worseoverall survival (HR=1.64; 95% CI=1.53-1.75) compared to the node-positive patients in the SLNB group.

Conclusion Our multicenter study shows that patients with a positive UGLNB have less favorable disease characteristics and a worse prognosis compared to patients with a positive SLNB. The diagnostic selection process plays an important role when axillary treatment strategies are considered. Therefore, we conclude that the conclusions of the Z0011 trial cannot (yet) be applied to patients with a positive UGLNB.

Citation Format: Verheuvel NC, Voogd AC, Tjan-Heijnen VCG, Roumen RMH. Use of axillary ultrasound impacts outcome of node positive breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-04.

Abstract P2-01-03: What to do with non-visualized sentinel nodes; to dissect or not to dissect the axilla?

Background Both in the literature and in international guidelines evidence is scarce on clinicopathological characteristics and axillary treatment recommendations in patients with a non-visualized sentinel node (nvSN) during the sentinel lymph node (SLN) procedure. Therefore, this study aims to evaluate the prevalence of nvSN in a Dutch population of breast cancer patients and to compare their characteristics and prognosis with patients in whom the SLN could be visualized. Moreover, we have distributed a questionnaire among certified oncological surgeons in the Netherlands in order to determine their routine regarding the axillary treatment after a nvSN.

Methods A retrospective population based study was performed including patients diagnosed with invasive breast cancer in the Netherlands between January 2000 and December 2013. Patients were included if they had no clinically palpable lymphadenopathy (cN0) or clinically apparent metastases (cM0). Patients receiving neo-adjuvant systemic treatment, patients with palpable axillary nodes and patients who did not undergo a SLN procedure were excluded.

Also, a questionnaire containing 10 questions regarding clinical routine during the sentinel node procedure and axillary treatment of nvSN patients was distributed among 150 oncological (breast) surgeons.

Results Of the 101,289 patients who fulfilled the inclusion criteria, 2545 (2.5%) had a nvSN. Univariate and multivariate analyses show that patients with a nvSN were older (p<0.001), were more often diagnosed in the years 2000-2005 (p<0.001), had a larger tumor (p=0.003) with more often a mastectomy (p=0.02) and were more likely to have ≥3 positive lymph nodes (p<0.001) compared to patients in whom the SLN could be visualized. However, adjusted survival analyses showed a borderline not-significant survival difference between these groups (HR=1.23, 95%CI=0.99-1.28). Of the 2545 patients with a nvSN, 2127 (84%) patients underwent an axillary lymph node dissection (ALND). Multivariate analyses show that patients receiving an ALND were more often diagnosed in the years 2000-2005, had a larger tumor and more often received adjuvant systemic therapy with both hormonal and chemotherapy. Adjusted survival analyses showed no statistically significant association between ALND and survival (HR=0.89, 95%CI=0.92-1.27).

The questionnaire was completed by 122 (24%) oncological (breast) surgeons. It showed that 39% of the respondents estimated the prevalence of a nvSN to be 1-2%. Most surgeons are currently more reserved to perform an ALND than before the Z0011 trial, depending on various clinicopathological characteristics; 23 respondents answered to opt for an alternative axillary treatment option.

Conclusion NvSN patients had worse disease characteristics compared to patients in whom the sentinel node could be visualized, though an ALND was not associated with a better survival. The results of the questionnaire show that surgeons are more reluctant to perform an ALND in case of a nvSN, especially after publication of the Z0011 trial, and that they would like the guideline to be revised and clarified regarding the axillary treatment in case of a nvSN.

Citation Format: Verheuvel NC, Voogd AC, Tjan-Heijnen VCG, Roumen RMH. What to do with non-visualized sentinel nodes; to dissect or not to dissect the axilla? [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-01-03.

Two decades of axillary management in breast cancer

Background

Axillary lymph node dissection (ALND) in patients with breast cancer provides prognostic information. For many years, positive nodes were the most important indication for adjuvant systemic therapy. It was also believed that regional control could not be achieved without axillary clearance in a positive axilla. However, during the past 20 years the treatment and staging of the axilla has undergone many changes. This large population-based study was conducted in the south-east of the Netherlands to evaluate the changing patterns of care regarding the axilla, including the introduction of sentinel lymph node biopsy (SLNB) in the late 1990s, implementation of the results of the American College of Surgeons Oncology Group Z0011 study, and the initial effects of the European Organization for Research and Treatment of Cancer AMAROS study.

Methods

Data from the population-based Eindhoven Cancer Registry of all women diagnosed with invasive breast cancer in the south of the Netherlands between January 1993 and July 2014 were used.

Results

The proportion of 34 037 women staged by SLNB without completion ALND increased from 0 per cent in 1993–1994 to 69·0 per cent in 2013–2014. In the same period the proportion undergoing ALND decreased from 88·8 to 18·7 per cent. Among women with one to three positive lymph nodes, the proportion undergoing SLNB alone increased from 10·6 per cent in 2011–2012 to 37·6 per cent in 2013–2014.

Conclusion

This population-based study demonstrated the radical transformation in management of the axilla since the introduction of SLNB and following the recent publication of trials on management of the axilla with a low metastatic burden.