Around 1% of all new cases of breast cancer (BC) diagnosed annually occur in men. Most research to date has focused on female breast cancer (FBC). So what is known about breast cancer in men has been mostly derived from the research and treatment of FBC. Comprehensive, prospective data about Quality of life in men treated for BC is lacking. Therefore, a validated worldwide questionnaire for male BC will be developed.

One percent of all new cases of breast cancer (BC) diagnosed annually is male BC. Although, the incidence increased by about 26% over the past 25 years, basic and clinical research focusing on male BC is limited. Care of male breast cancer is largely based on extrapolation from treatment strategies and management of symptoms in women. Comprehensive, prospective data about QoL in men treated for BC are lacking. A few studies have focused on symptoms and two small studies have focused on QoL.

The evaluation of the QoL issues relevant for male BC, as well as the translation of issues into items to build the tool for QoL assessment in male BC will be carried through four phases: 1.Literature review: A systematic review with the question what factors are unique to male BC in influencing their QoL and what QoL measures exist for male BC will be done by review of all studies with male BC, investigator brochures (IB) of the describing side effects, review of the existing issues in other EORTC modules . 2. Interviews with patients: Interviews with patients will be undertaken to get information on the most relevant issues influencing QoL. The interviews can be held face-to-face or via telephone. The patient interviews are used to create a list of relevant and important issues which are already covered by the EORTC QLQ-C30, QLQ-BR45 and QLQ-PR25. A semi-structured interview will be carried out. In case of phone interviews, the study documents are handed out in advance so that the patient has the documents available during the interview. Patients will also be asked to rate the importance of each of the items ( 4-point Likert scale) , the appropriateness of the way the items are phrased and about options of alternative wording for items, which a priori are likely to be different for female BC or prostate patients with cancer. Additional issues will be documented carefully. 3.Interviews with health care professionals (HCP): HCP with special knowledge in the field will be interviewed to discuss and consider the potential issues (experts from the EORTC QLG, collaborating centres, EORTC Breast Group, as well as experts from the International Male BC Consortium Group). 4.Consultation of experts in Oncology and QoL: We will seek expert advice from experts in the field of treatment of male BC and in Qol assessment. The study proposes to gather all available evidence from the literature, as well as data from the qualitative interview and develop a succinct summary. Experts will be asked to comment on our findings and will also be asked specific questions around the necessity of the development of a new module, based on those findings and their expert views. These data will be collated and reported in the final report.

The study proposes to carry out an evaluation of the QoL issues relevant for male BC, and translating the issues in the items to build the tool for QoL assessment in male BC. The specific aims are:

1. To carry out an evaluation of the EORTC QLQ-BR 45 (adapting for male BC) and for suitability of use in male BC patients
2. To carry out an evaluation of the EORTC QLQ-PR25 (adapting for male BC) for suitability of use in male BC patients
3. To provide recommendations to the EC on a suitable assessment approach to assess HRQOL in male BC

Inclusion Criteria:

1. Male sex
2. Evidence of invasive breast cancer (any type) and/or ductal carcinoma in situ (DCIS) (current or anamnestic).
3. Must be able and willing to complete the questionnaires.
4. Must be able to understand and speak the language in which the patient will complete the questionnaire.

Exclusion Criteria:

1. Cognitive impairment

Interviews with patients, who meet the eligibility criteria will be undertaken to get information on the most relevant issues influencing QoL. Also HCP with special knowledge in the field will be interviewed to discuss and consider the potential issues (experts from the EORTC QLG, collaborating centres, EORTC Breast Group, as well as experts from the International Male BC Consortium Group).