Table 1.

5-year survival based on treatment assignment and tumor thickness in randomized trials

	Intermediate			Thick			All intermediate/thick
Trial	Early	Observation	Δ	Early	Observation	Δ	Early	Observation	Δ
WHO#1	78.5%	69.7%	8.8%	52.9%	51.7%	1.2%	71%	65%	4%
WHO#14	68%	49%	19%	66%	63%	3%	61.7%	51.3%	10.4%
Intergroup	89%	84%	5%	57%	59%	−2%	86%	82%	4%
MSLT-I*	69.8%	57.5%	12.3%	60.8%	53.8%	7%	NR	NR	NR

Intermediate thickness: WHO#1: 1.6–4.5mm, WHO#14 1.5–4.0 mm, Intergroup: 1–2 mm, MSLT-I: 1.2–3.5mm

Thick: WHO#1: >4.5mm, WHO#14: >4mm, Intergroup 3.1–4mm, MSLT-I: >3.5 mm

^*Node positive only

WHO: World Health Organization, MSLT: Multicenter Selective Lymphadenectomy Trial, NR: Not Reported