Rationale:~Seroma formation, a collection of serous fluid containing blood plasma and/or lymph fluid, is a common complication in breast cancer surgery and can lead to delayed wound healing, infection, skin flap necrosis, patient discomfort and repeated visits to the outpatient clinic and therefore extensive research has been done to further elucidate the pathophysiology and prevention of seroma formation. Promising results have resulted from studies focusing on flap fixation in order to reduce the incidence of seroma and seroma aspirations. Mastectomy with flap fixation is becoming standard practice and is currently combined with closed-suction drainage. Closed-suction drainage is considered gold standard for reducing seroma formation after breast cancer surgery. However, evidence shows that closed-suction drainage is insufficient in preventing seroma formation. One might wonder if there is still a place for closed-suction drainage after mastectomy if flap fixation is performed. The promising results in flap fixation could exclude drainage systems in breast cancer surgery. However, the available data consist of small case series and therefore a large randomized controlled trial is needed for it to be widely implemented.~To our knowledge, no randomized controlled trial has been conducted comparing flap fixation with and without closed-suction drainage with seroma aspiration as the primary outcome.~The investigators hypothesize that flap fixation with closed suction drainage does not cause a significant lower incidence of seroma aspirations, when compared to flap fixation alone. The investigators also expect that patients without drainage will experience significantly less discomfort and comparable rates of surgical site infections.~Objective: To prove that omitting drains after mastectomy and flap fixation does not contribute to higher incidence of seroma formation and therefore reducing patient disutility such as seroma aspirations and visits to the outpatient clinic, as well as reducing seroma related wound complications.~Study design: Prospective randomized controlled trial~Study population: Female patients > 18 years diagnosed with invasive breast cancer or DCIS (ductal carcinoma in situ) with an indication to perform mastectomy~Intervention (if applicable):~Mastectomy with flap fixation using sutures with closed suction drainage~Mastectomy with flap fixation using sutures without closed suction drainage~Main study parameters/endpoints:~Patients undergoing seroma aspiration (clinically significant seroma (CSS)).~Nature and extent of the burden and risks associated with participation, benefit and group relatedness:~Patients will be informed about the study before inclusion in the outpatient clinic. Informed consent will be obtained in the outpatient clinic a week after patients were initially informed. Postoperative check-ups will be done more frequently. Standard postoperative check-ups are planned at 2 weeks and 3 months. Additional study postoperative check-ups: 6 weeks, 6 months. Therefore, patients will be required to undergo two additional check-ups.~During out patients' visits, patients will hand in a questionnaire scale regarding cosmesis, pain and quality of life.~Patients will be clinically examined as they usually would be.
To prove that omitting drains after mastectomy and flap fixation does not contribute to higher incidence of seroma formation and therefore reducing patient disutility such as seroma aspirations and visits to the outpatient clinic, as well as reducing seroma related wound complications.