The patient selection process varies among the different study sites. Three Hospitals (Sismanogleio General Hospital Athens (SGHA), Örebro University Hospital (ÖUH), Uppsala University Hospital (UUH)) will include patients with newly diagnosed breast- (ÖUH, UUH) or prostate cancer (SGHA, ÖUH) who are eligible for curative treatment with surgery (breast cancer in ÖUH and UUH; prostate cancer in NKUA) or radiotherapy (prostate cancer; ÖUH).  One Hospital (Barcelona) will include breast cancer survivors (at least 12 months after surgery or chemotherapy) with follow-up through the Hospital.  Finally, CareAcross will include patients with breast- or prostate cancer through its online platform for patients seeking for the CareAcross services.  Inclusion Criteria (breast cancer; ORB and Uppsala):  breast cancer diagnosis no clinical evidence of metastatic disease able for curative treatment with surgery with or without oncological treatment.  Inclusion Criteria (breast cancer; Barcelona)  prior early breast cancer who are at follow-up with at least 12 months after surgery or chemotherapy (whichever occurred last).  Inclusion Criteria (breast cancer; CareAcross)  breast cancer diagnosis (as per self-reported) irrespective of stage and treatment.  Inclusion Criteria (prostate cancer; SGHA and ORB)  proostate cancer diagnosis no clinical evidence of metastatic disease able for curative treatment with surgery with or without oncological treatment (SGHA) or radiotherapy (with or without prior surgery) irrespectively the type of radiotherapy (external radiotherapy, brachytherapy, or combination).  Inclusion Criteria (prostate cancer; CareAcross)  prostate cancer diagnosis (as per self-reported) irrespective of stage and treatment.  Exclusion Criteria (common in all study sites):  inability to give informed consent inability / no access to smartphones, applications or internet services patients with known medical history of allergy to the wearable material.