Table 5.

Definitions of outcomes for each study included in the systematic review

Authors (year) or study name, country	Outcomes	Outcomes definition
DIANA-2
Berrino et al. (2005) [20]	Recurrence (local relapse, distant metastasis, contralateral breast cancer)	Local relapse, distant metastasis, contralateral breast cancer occurred over 5.5 years of follow-up
Pasanisi et al. (2006) [21]	Recurrence (local relapse, distant metastasis, contralateral breast cancer)	Local relapse, distant metastasis, contralateral breast cancer occurred over 5.5 years of follow-up
Pasanisi et al. (2008) [22]	Recurrence (local relapse, distant metastasis, contralateral breast cancer)	Local relapse, distant metastasis, contralateral breast cancer occurred over 5.5 years of follow-up
DIANA-5
Berrino et al. (2014) [23]	Recurrence (loco-regional recurrences, distant metastasis and new primary breast cancer) and breast cancer mortality	Loco-regional recurrences, distant metastasis and new primary breast cancer, and deaths due to breast cancer occurred over a median of 2.8 years of follow-up
PACThe study
Vasson et al. (2020) [24]	Disease-free survival (absence of local or distant (nodes, metastasis, and/or contralateral breast cancer))	Disease-free interval was computed as months elapsed from date of randomization to documented breast cancer recurrence during 7 years after breast cancer treatment completion. All recurrence types were considered, either local or distant (nodes, metastases, and/or contralateral breast cancer)
WHEL study
Emond et al. (2011) [25]	Recurrence (local, regional, or distant, or new primary events)	Events were defined as local, regional, or distant recurrence, or new primary; the WHEL study did not include ductal carcinoma in situ or lobular carcinoma in situ as events. Time to outcome was date of randomization to date of additional event. Women who did not have an additional event were assessed for outcome at the date of last contact or study end (June 1, 2006). Women who died due to conditions unrelated to breast cancer were assessed for outcome at the date of death. WHEL further excluded women who had a breast cancer recurrence within the first year of study enrollment
Al-Delaimy et al. (2011) [26]	Breast cancer event (recurrent/new primary breast cancer event)	Reported breast cancer recurrence or new primary breast cancer diagnosed after study enrollment
Villaseñor et al. (2013) [27]	Additional breast cancer events (recurrence or new primary breast cancer) and breast cancer mortality	Women were followed during the follow-up for vital status, from study entry until end of study, June 1, 2006
	All-cause mortality