Tangential fields in pN+ sentinel nodes breast cancer with or without axillary dissection.
PD-0744
Abstract
Tangential fields in pN+ sentinel nodes breast cancer with or without axillary dissection.
Authors: Marzia Borgia1, Marianna Nuzzo1, Lucia Anna Ursini1, Consuelo Rosa1,2, Fiorella Cristina Di Guglielmo1, Marco Lucarelli1, David Fasciolo1, Domenico Genovesi1,2
1SS. Annunziata Hospital, Department of Radiation Oncology, Chieti, Italy; 2G. D’Annunzio University, Department of Neuroscience, Imaging and Clinical Sciences, Chieti, Italy
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Purpose or Objective
In the past, axillary
dissection (ALND) was performed for tumour staging and to improve local control
(LC). Axillary management in cN0 breast cancer (BC) patients
with positive sentinel lymph node (SLN) is unclear in case of ALND omission. The
ACOSOG Z0011, comparing cN0 patients and positive SLN treated with or without
ALND, demonstrated ALND safety omission; this study was although criticized for
adjuvant radiotherapy (RT) non uniformity. We conducted the LISEN trial with ALND
omission in cN0 and positive SLN patients who met the ACOSOG Z0011 criteria.
These patients were treated with whole breast radiotherapy (WBRT) without high
tangent or nodal irradiation. Subsequently, we compared LISEN patients with a retrospective
group with similar pathological characteristics who underwent ALND and same RT
fields.
Material and Methods
In LISEN trial we analysed female
patients with histologically confirmed invasive BC at biopsy, cT1-2cN0, submitted
to conservative surgery with SLN biopsy. Adjuvant
systemic therapy was prescribed according to staging and tumor biology. Tangential
fields WBRT was planned without high tangent or nodal irradiation.We search in
our database patients with similar characteristics who underwent ALND and WBRT
without nodal irradiation (group 1) and compared with LISEN patients (group 2).
Clinical outcomes, local
recurrence (LR), regional recurrence (RR), loco-regional recurrence (LRR),
distant metastases (DM), disease-free survival (DFS) and overall survival (OS),
were analyzed, measured from surgery until first event.
Results
Two hundreds and nine patients were analysed (76 in group 1 and 133 in
group 2). Patients, tumor and treatment characteristics are reported in Table
1.The median number of removed nodes was 12 for group 1 and 2 for group 2. The
median number of histologically positive nodes was 1 in both groups. In group 1,
all patients (100%) underwent WBRT with conventional fractionation (50
Gy in 25 fraction). In group 2, 126 (94.7%) received a
conventional fractionation and 7 (5.3%) hypofractionation (from 40 to 40.05 Gy
in 16-15 fraction).
The median follow-up was 92 months (range= 21-131) for
group 1 and 50 months (range= 5-91) for group 2.
In group 1, the 9-year LR was 2.6%, RR: 1.3%, LRR: 0%, DM: 2.6%. In group
2, the 5-year LR was 3.2%, RR: 1.5%, LRR: 1.5% and DM: 6.7%.
OS and DFS were 94.7 and 94.7 in group 1 and 93.6 and 96 in group 2
respectively.
Comparing the two
groups, LR occurred in 2 and 4 patients, RR in 1 and 1, DM in 2 and 5 and death
in 4 and 1, in group 1 and 2 respectively.
Conclusion
Similar outcomes were reported in both groups.
Although the longer follow up for group 1 and the greater number of patients in
group 2, ALND seems to improve LC and DM although its omission seems to have
not a worse impact on DFS and OS, sparing axillary morbidities. A longer
follow-up is necessary to confirm these results.