Abstract P3-20-05: Trends of axillary treatment in sentinel node-positive breast cancer patients undergoing amputation

Abstract

Objectives: To evaluate patterns of care in axillary treatment of Dutch patients - who were diagnosed with stage I-IV primary invasive breast cancer, underwent amputation and were found positive by sentinel lymph node biopsy (SLNB) - in the years following the publication of the American College for Surgeons Oncology Group (ACOSOG)-Z0011 and After Mapping of the Axilla: Radiotherapy Or Surgery (AMAROS) trials. Methods: Data from females diagnosed between January 1st 2009 and December 31st 2018 were obtained from the Netherlands Cancer Registry (NKR). Trends in completion axillary lymph node dissection (cALND), administration of adjunctive radiotherapy and, inversely, of omission of any kind of axillary treatment, were revealed by descriptive analyses on SNL positive patients. Results: Of 28,070 cT1-4 breast cancer patients undergoing amputation with SLNB from 2009 up until 2018, 10,706 were diagnosed as SLN positive. In the latter, the frequency of subsequent cALND went down significantly from 78% in 2009 to 10% in 2018 (P < 0.001), while adjunctive radiotherapy increased from 4% to 49% (P < 0.001). Omission of any additional local treatment increased from 18% to 41% (P < 0.001). In N1 patients cALND decreased from 57% to 13% (P < 0.001) and was mostly replaced by radiotherapy, increasing from 2% to 70% (P < 0.001). In N1mi and N0i+ patients, cALND decreased to less than 1% of cases in 2018, while radiotherapy increased from 4% to 40% and 8% to 13% (P < 0.001), respectively. Conclusion: In SLN positive breast cancer patients undergoing breast amputation, cALND had become rare 10 years following the AMAROS and Z0011 trial results. While radiotherapy mostly replaced cALND in the vast majority of N1 patients, less than half of N1mi and only a tenth of N0i+ patients received radiotherapy as the only adjunctive axillary treatment by the end of 2018. Citation Format: Eline EF Verreck, Julia van Steenhoven, Anne Kuijer, Marissa van Maaren, Sabine Siesling, Thijs van Dalen. Trends of axillary treatment in sentinel node-positive breast cancer patients undergoing amputation [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-20-05.

Patterns of completion axillary dissection for patients with cT1‐2N0 breast cancer undergoing total mastectomy with positive sentinel lymph nodes

“…Our data, similar to Verreck et al, suggest that prior studies including IBCSG 23‐01, ACOSOG Z0011, and AMAROS likely have had a significant impact on the surgical management of the axilla for patients undergoing breast surgery by omitting ALNDs 8,10,12 . This trend has been described in other studies as well 19–21 . Similarly, a recent retrospective study using the NCDB (2006–2014), found that while ALND has decreased over time for mastectomy patients with positive SLNs, PMRT has increased over time 21,22 .…”

“…8,10,12 This trend has been described in other studies as well. [19][20][21] Similarly, a recent retrospective study using the NCDB (2006-2014), found that while ALND has decreased over time for mastectomy patients with positive SLNs, PMRT has increased over time. 21,22 Within the ALND group in our study, 44.5% underwent radiation treatment, while in the SLNB group, 38.5% underwent radiation treatment.…”

“…Notably, this trend is observed in the time period immediately following the publication of findings from the IBCSG 23‐01, ACOSOG‐Z001, and AMAROS trials regarding axillary treatment in SLNB‐positive breast cancer patients. A recent study by Verreck et al prospectively examined patterns of ALND and axillary treatment options in SLNB‐positive patients undergoing mastectomy 19 . This population‐based study ( N = 10 633) demonstrated a reduction of the frequency of ALND from 78% to 10% from 2009 to 2018, and an increase in postmastectomy radiation therapy (PMRT) from 4% to 49% ( p < 0.001).…”