Inclusion Criteria:

- General inclusion criteria

1. Age ≥ 70 years old.

2. New or progressive cancer (breast, lung, colorectal, prostate), histologically proven or strong clinical suspicion, fulfilling the tumor specific criteria.

3. Estimated life expectancy greater than 6 months.

4. At least one moderate/severe multimorbidity inclusion criteria other than current cancer (see separate list under 5.3).

5. Patients must be willing and able to comply with study procedures.

6. Voluntarily signed and dated written informed consents prior to any study specific procedure.

7. QLQ-C30 Quality of Life Questionnaire fully completed at baseline, before inclusion.

8. Patients affiliated with a French social security scheme in accordance with the French law on biomedical research (Article 1121-11 of the French Code of Public health).

   Tumor specific inclusion criteria

9. Specific inclusion criteria for breast cancer:

   9.1. Non-metastatic breast cancer (M0):

   - No prior treatment for the current breast cancer.

   - All 3 criteria required:

   o Clinical staging: cT2-3-4 Nany, or cTany N1-2-3;

   • The cancer specialist considers* surgery;

   • The cancer specialist considers* radiotherapy and/or chemotherapy. 9.2. Metastatic breast cancer (M1): Both criteria required:

     • The cancer specialist considers* chemotherapy or PARP-inhibitors or mTOR-inhibitors / PIK3CA inhibitors; Previous endocrine therapy +/- CDK4/6 inhibitors is allowed;

     • The patient received maximum 1 prior line of chemotherapy for metastatic disease.

       • 'consider' implies that this treatment may be a treatment option for this patient in this particular setting. If at a later point, a different treatment choice is made, the patient remains eligible.

10. Specific inclusion criteria for colorectal cancer:

    10.1. Non-metastatic colorectal cancer (M0):

    - No prior therapy for the current tumor in the recruiting hospital

    • At least one of the 3 criteria required:

      o The cancer specialist considers* surgery;

      • The cancer specialist considers* radiotherapy;
      • The cancer specialist considers* chemotherapy and/or immunotherapy. 10.2. Metastatic colorectal cancer (M1):

    • The cancer specialist considers* first or second line systemic therapy and/or radiotherapy (+/- surgery). No previous chemotherapy allowed except adjuvant/perioperative chemotherapy stopped for more than 12 months.

      • 'consider' implies that this treatment may be a treatment option for this patient in this particular setting. If at a later point, a different treatment choice is made, the patient remains eligible.

11. Specific inclusion criteria for lung cancer:

11.1. Non-metastatic lung cancer (M0):

• No prior therapy for the current tumor in the recruiting hospital

• At least one of the 3 criteria required:

  • The cancer specialist considers* surgery (patients considered for treatment with percutaneous thermoablation alone are not eligible);
  • The cancer specialist considers* radiotherapy (except SBRT);
  • The cancer specialist considers* systemic therapy. Possible systemic therapies are chemotherapy and/or immune therapy and/or targeted therapy. Patients only considered* for monotherapy with anti-EGFR TKI or somatostatin analog are not eligible.

11.2. Metastatic lung cancer (M1):

• The cancer specialist considers* first or second line systemic therapy. Possible systemic therapies are chemotherapy and/or immune therapy and/or targeted therapy. Patients only considered* for monotherapy with anti-EGFR TKI or somatostatin analog are not eligible.

  *'consider' implies that this treatment may be a treatment option for this patient in this particular setting. If at a later point, a different treatment choice is made, the patient remains eligible.

  12. Specific inclusion criteria for prostate cancer: 12.1. Non-metastatic prostate cancer (M0): one of the following:

• First diagnosis M0 prostate cancer (no therapy received yet for prostate cancer): at least one of the 2 criteria required:

  o The cancer specialist considers* radiotherapy;

  o The cancer specialist considers* hormone therapy (ADT +/- combination Abiraterone and Prednisone).

• Salvage treatment M0 prostate cancer (received prior surgery at least 6 months before):

  o The cancer specialist considers* radiotherapy (+/- ADT)

• Non-metastatic castration resistant prostate cancer:

  • The cancer specialist considers* treatment intensification (ADT + Enzalutamide or Apalutamide or Darolutamide).

12.2. Metastatic prostate cancer (M1): - The cancer specialist considers* treatment with Abiraterone or Enzalutamide or Apalutamide, or Docetaxel or Cabazitaxel or PARP-inhibitors or Lutetium PSMA.

*'consider' implies that this treatment may be a treatment option for this patient in this particular setting. If at a later point, a different treatment choice is made, the patient remains eligible.

Exclusion Criteria:

1. Mental illness/cognitive impairment that limits ability to provide consent or complete trial procedures.
2. Participating to an interventional clinical trial with a non-registered anticancer drug or to another geriatric intervention trial.
3. Patients and caregivers are unable or unwilling to use ICT-devices (tablet,computer, smartphone) or the Internet according to protocol.
4. Patient already included in this study.