The effect of omitting axillary dissection and the impact of radiotherapy on patients with breast cancer sentinel node macrometastases: a cohort study following the ACOSOG Z0011 and AMAROS trials.

PURPOSE: To report the outcomes of implementing the ACOSOG Z0011 and AMAROS trials relevant to clinical practice, and to define target groups in whom to avoid or recommend axillary radiotherapy (ART). We also aimed to analyse the reduction in morbidity when axillary lymph node dissection (ALND) was omitted. METHODS: A retrospective cohort study of T1-T2 patients with macrometastases at sentinel lymph node (SLN) who were treated between 2011 and 2020. Breast surgery included either lumpectomy or mastectomy. Patients with ≤ 2 positive SLN were divided into two cohorts by whether they received ART or not. Survival outcomes and morbidity were analysed by Kaplan-Meyer curves and Cox-regression, respectively. RESULTS: 260 pN1a patients were included and ALND was avoided in 167 (64.2%). According the Z0011 results, 72 (43.1%) received no further ART; and based on AMAROS criteria 95 (56.9%) received ART. Median follow-up was 54 months. The 5-year overall survival was 96.8% in the non-RT cohort and 93.4% in the RT cohort (p = 0.19), while the respective 5-year disease-free survivals were 100% and 92.3% (p = 1.06). Lymphedema developed in 3.6% of patients after SLNB versus 43% after ALND (OR 20.25; 95%CI 8.13-50.43). Decreased upper-extremity range of motion appeared in 8.4% of patients after SLNB versus 31.2% after ALND (OR 4.95; 95%CI 2.45-9.98%). CONCLUSIONS: Our study confirms that omitting ALND is safe and has high survival rates in patients with T1-T2 tumours and ≤ 2 positive SLNs. Adding ART could be a treatment option for patients who present other risk factors. Avoiding ALND with or without ART was associated with significantly less arm morbidity.

The Shift From Sentinel Lymph Node Biopsy Performed Either Before or After Neoadjuvant Systemic Therapy in the Clinical Negative Nodes of Breast Cancer Patients. Results, and the Advantages and Disadvantages of Both Procedures.

BACKGROUND: In patients with breast cancer who are candidates for neoadjuvant therapy (NAT), the timing of when to perform sentinel lymph node biopsy (SLNB) remains under discussion. The aim of this study was to compare the advantages and disadvantages of SLNB performed before and after NAT. PATIENTS AND METHODS: One hundred seventy-two patients, T1c to T3 and N0 (clinically and according to ultrasound) candidates for NAT were included. We compared the outcomes of 2 groups: (1) 122 patients of whom SLNB was performed before NAT (pre-NAT) from December 2006 to April 2014; and (2) 50 patients with SLNB performed after NAT (post-NAT) from May 2014 to July 2016. RESULTS: Both groups were homogeneous in baseline patient characteristics. The SLNB was positive in 50 patients [41.7%] (33 macrometastases [66%] and 17 micrometastases [34%]) versus 6 patients [12%] (5 macrometastases [83.3%] and 1 micrometastases [16.7%]) in pre- and post-NAT groups, respectively. The lymphadenectomy was performed in 34 patients [28.3%] versus 4 patients [8%], with an odds ratio of 3.48 (95% confidence interval, 1.3-9.3). The recurrences in the pre-NAT group after a median follow-up of 62 months were 12 systemic, 2 local and systemic, and none axillary. In the post-NAT group were no recurrences after a median follow-up of 16 months. Finally, SLNB after NAT reduces the delay in starting NAT from 24 to 14 days (medians; P < .001) and the identification of the SLNB was in 122 patients [100%] versus 49 patients [98%]. CONCLUSION: SLNB performed after NAT significantly reduces the rate of lymphadenectomies without any increase in recurrences at early follow-up. Furthermore, it allows systemic treatment to be started earlier without interfering in the SLNB identification rate.

Feasibility, accuracy and prognosis of sentinel lymph node biopsy before neoadjuvant therapy in breast cancer. A prospective study.

BACKGROUND AND OBJECTIVE: It remains controversial whether sentinel lymph node biopsy (SLNB) should be performed before or after neoadjuvant therapy (NAT). We aimed to evaluate the feasibility and accuracy of SLNB before NAT at a single institution, and to determine its relation to patient prognosis. METHODS: A prospective study of T1c-T2-T3 N0 breast cancer patients, after ultrasound examination, who underwent SLNB prior to NAT. Overall, disease-specific and disease-free survival were calculated by Kaplan-Meier curves. RESULTS: SLNB before NAT was performed in 123 patients from December 2006 to May 2014. The identification rate was 100%. SLNB was positive in 42.3% of cases (27.6% macrometastases). NAT was chemotherapy in 88.6% of cases and endocrine-therapy in 11.4%. Lymphadenectomy was avoided in 72.4% of cases. Median follow-up was 40 months (range 8-100). Overall and disease-free survival was 90.2% and 88.6% respectively.SLN involvement was not related to patient outcome (p 0.72); however there were significant differences in survival according to molecular-like subtypes (p < 0.025) and NAT response (p < 0.0001). CONCLUSIONS: SLNB prior to NAT is an accurate method of axillary staging associated with a high identification rate. It avoided lymphadenectomy in more than 70% of patients. SLN involvement did not worsen the prognosis in our cohort.

Particle sizes of colloids to be used in sentinel lymph node radiolocalization.

OBJECTIVES: To investigate particle size distribution and possible effects of colloid concentration and time after its preparation on the particle sizes of albumin nanocolloid (Nanocoll), rhenium sulfide nanocolloid (Nanocis) and tin colloid (Hepatate). METHODS: All three kits were prepared according to the manufacturers' instructions using the following volumes of decayed Tc generator eluate: 1.5 ml, 3.5 ml and 5.0 ml (albumin nanocolloid); 1.0 ml, 2.0 ml and 3.0 ml (rhenium sulfide nanocolloid); 3.0 ml, 5.0 ml and 9.0 ml (tin colloid). The particle sizes were determined by photon correlation spectroscopy inmediately after preparation, then at 30 min, 1 h, 2 h, 3 h and 4 h (all three kits) and at 6 h (Nanocoll and Hepatate). Each measurement was performed in three different preparations. RESULTS: The particle sizes of the three colloids did not change significantly after preparation throughout their period of validity. For Nanocoll, 95% of the particles were between 3 and 16 nm, approximately (mean around 8 nm). Small (< or =1 nm) but significant variations on the mean diameter were found depending on the volume of pertechnetate used in the preparation. For Nanocis, 95% of the particles were between 8 and 68 nm, approximately (mean around 23-25 nm). In this kit, there were no significant differences among colloidal suspensions prepared with different volumes of pertechnetate. For Hepatate, 95% of the particles were between 33 and 255 nm, approximately (mean, around 72-90 nm). The upper limit and the mean size increase with the volume of eluate used were from 190 nm and 73 nm (3 ml) to 255 nm and 85 nm (9 ml). CONCLUSIONS: The particle sizes of Nanocoll, Nanocis and Hepatate are very stable throughout their period of validity. For Nanocoll, 95% of particles have a diameter <16 nm, with a mean diameter around 8 nm. There are small (< or =1 nm) but significant variations on the mean diameter depending on the volume of pertechnetate used in its preparation. For Nanocis, 95% of particles have a diameter <70 nm, with a mean around 24 nm, and are independent of the volume of pertechnetate used in their preparation. For Hepatate, the upper size limit for 95% of particles is between 190 and 255 nm, with a mean between 72 and 88 nm, depending on the volume of pertechnetate used in its preparation. This tin colloid could be a good candidate for evaluating clinical suitability in sentinel node localization.