The investigators will perform a pilot study to gain insight into attitudes, barriers and facilitators for health behavior change in cancer patients and their partners. Results of this pilot will be used to design suitable questionnaires to investigate health behavior change in a larger cohort of patients and their partners. It will also direct future interventions to adequately target patients and, potentially, their partners to improve their lifestyle following a cancer diagnosis.

The investigators will perform semi-structured interviews with cancer patients and their partners in order to explore knowledge, attitudes, barriers and facilitators regarding health behavior change following cancer treatment.

Inclusion Criteria:

• between 18 and 65 years of age
• have completed adjuvant or curative chemotherapy (in BC and TC patients, respectively) or started adjuvant hormonal therapy alone (in BC patients) between 6 and 24 months previously
• have no signs or symptoms of recurrent disease
• be in follow-up at the Department of Medical Oncology of the UMCG.

Exclusion Criteria:

• signs or symptoms of recurrent disease
• mental disability

The investigators will invite 10 women with early stage breast cancer (BC) and 10 men with disseminated testicular cancer (TC) and their partners (20 couples in total).