Future research
As we found no medium to large effect of manual lymph
drainage (in addition to guidelines and exercise therapy) on the
development of lymphoedema related to breast cancer, a future
study should be performed to determine whether it has a small
effect. The power calculation could be based on the combination
of the cumulative incidence rates for arm lymphoedema from
the study of Lacomba et al and our study, which leads to an
estimated cumulative incidence of 16% ((4+18)/(59+77)) in the
intervention group and 21% ((14+15)/(57+81)) in the control
group. We need to continue to follow up our patients as 20-33%
of patients with breast cancer who develop arm lymphoedema
will do so more than 12 months after surgery.