. Author manuscript; available in PMC: 2023 Jul 27.

Published in final edited form as: Ann Surg. 2023 Apr 6;277(5):e1106–e1115. doi: 10.1097/SLA.0000000000005370

Table 2.

Institutional factors associated with nodal management and adjuvant treatment

	Nodal observation^a	P-Value	Nodal observation with adjuvant^a	P-Value	CLND alone^a	P-Value	CLND with adjuvant^a	P-Value
All Centers	47% (0–92%)		43% (0–77%)		5% (0–83%)		7% (0–33%)	N/A
Region
Australia	50% (35–56%)	0.13	44% (18–62%)	0.03^c	1% (0–18%)	0.47	1% (0–14%)	0.08^d
Europe	73% (11–92%)		17% (0–27%)		8% (0–83%)		0% (0–7%)
US	41% (0–67%)		44% (2–77%)		5% (0–23%)		9% (0–33%)
Volume tertile (# SLN+ pts/yr)
Low (6–15)	27% (0–92%)	0.42	38% (0–77%)	0.95	8% (0–83%)	0.77	7% (0–33%)	0.65
Mid (16–27)	49% (21–67%)		41% (2–66%)		6% (0–22%)		10% (0–11%)
High (28–90)	50% (34–73%)		43% (15–62%)		1% (0–23%)		1% (0–19%)
Cancer center^b
Yes	43% (0–73%)	0.46	44% (0–77%)	0.37	4% (0–83%)	0.75	7% (0–19%)	0.66
No	51% (10–92%)	0.46	18% (0–57%)	0.37	8% (0–18%)	0.75	7% (0–33%)	0.66
MSLT-2 trial participant
Yes	49% (21–56%)	0.60	33% (0–77%)	0.06	1% (0–83%)	0.16	7% (0–33%)	0.50
No	45% (0–92%)	0.60	49% (24–71%)	0.06	8% (0–17%)	0.16	9% (0–11%)	0.50

Analysis by treating center reported as the proportion of patients at each treating center who received each treatment category with values representing center-level medians and ranges

National Cancer Institute-designated, European Society of Medical Oncology-designated, or self-designated cancer centers for those outside NCI or ESMO jurisdiction; CLND=completion lymph node dissection; US=United States; SLN+=sentinel lymph node positive; pts=patients; yr=year; MSLT-2=Second Multicenter Selective Lymphadenectomy Trial

p=0.01 for comparison of rates in US versus Europe, 1.00 for US versus Australia, 0.14 for Europe versus Australia

p=0.04 for comparison of rates in US versus Europe, 0.55 for US versus Australia, 0.64 for Europe versus Australia