Case series Patient: - Final Diagnosis: Breast cancer Symptoms: Medication: - Clinical Procedure: - Specialty: - Objective: Diagnostic/therapeutic accidents Background: Several well-established, evidence-based treatment modalities are currently available and widely applied to breast cancer patients, but it is known that some of the cancer patients use traditional/alternative medicine other than their treatments. Case Report: Herein, we report the cases of 2 middle-aged women (45 and 50 years old) with malignant breast masses who experienced serious complications in response to self-prescribed use of alternative medicine practices to treat their condition in lieu of evidence-based medical treatment. Specifically, the use and/or inappropriate application of alternative medical approaches promoted the progression of malignant fungating lesions in the breast for these 2 patients. The first patient sought medical assistance upon development of a fungating lesion 7 similar to 8 cm in diameter and involving 1/3 of the breast, with a palpable mass of 5x6 cm immediately beneath the wound. The second patient sought medical assistance upon development of a wide, bleeding, ulcerous area with patchy necrotic tissue that comprised 2/3 of the breast and had a 10x6 cm palpable mass under the affected area. Use of some non-evidence-based medical treatments as complementary to evidence-based medical treatments may benefit the patient on an emotional level; however, this strategy should be used with caution, as the non-evidence-based therapies may cause physical harm or even counteract the evidence-based treatment. Conclusions: A malignant, fungating wound is a serious complication of advanced breast cancer. It is critical that the public is informed about the potential problems of self-treating wounds such as breast ulcers and masses. Additionally, campaigns are needed to increase awareness of the risks and life-threatening potential of using non-evidencebased medical therapies exclusively.