Breast cancer surgery has evolved towards ever more breast conserving direction. Even thought the surgical regime has become easier for the patient, many instructions given to the patient after the operation base on instructions, which have been used when the performed operations have been more burdensome.

Previously the patients have been instructed to lift only light objects after the operation, but according to the current knowledge, this instruction might be unnecessary.

The meaning of this study is to compare two patient groups to each other. The other group is instructed to avoid lifting, and the other group is given instructions to lift light weights several times daily.

In the study we compare will this have an effect on

1. incidence of upper limb lymphedema
2. seroma formation after surgery
3. quality of patients life after the surgery

Inclusion criteria is patients underoing mastectomy but no axillary clearance on day-care basis. Patietns will be randomized in two groups, the other as an intervention group and other as an control group. The patients are asked to fill a questionnaire considering recovery from the operation and possible wound healing problems. The amount of seroma is recorded. The volume of upper limbs is measured before and after the surgery.

The study is started in January 2022 and finished in December 2024.

Inclusion Criteria:

• patients with breast cancer diagnosis requiring mastectomy
• patients being operated in day-care regime

Exclusion Criteria:

• patients not eligible for day-care mastectomy
• patients undergoing axillary clearance operation