About
Professor Mary O'Brien was born in Northern Ireland and studied medicine at Trinity College Dublin. She works as a medical oncologist in the NHS at The Royal Marsden in Sutton, Surrey.
Professor O'Brien treats breast and lung cancer including mesothelioma. She is currently chair of the National lung cancer study subgroup (LORD) and past chair of the European EORTC lung cancer group. She is the chief investigator of the international adjuvant PEARLS study looking at the role of immunotherapy after surgery for lung cancer. She has a large experience of immunotherapy.
For lung and breast cancer she is interested in all aspects of treatment development through clinical trials. She is also interested in the supportive treatment of cancer patients including the use of acupuncture.
Diseases, Medical Tests and Treatments
Breast Cancer
Lung Cancer
Mesothelioma
Breast Cancer
Lung Cancer
Mesothelioma
Professor O'Brien treats breast and lung cancer including mesothelioma. She is currently chair of the National lung cancer study subgroup (LORD) and past chair of the European EORTC lung cancer group. She is the chief investigator of the international adjuvant PEARLS study looking at the role of immunotherapy after surgery for lung cancer. She has a large experience of immunotherapy.
For lung and breast cancer she is interested in all aspects of treatment development through clinical trials. She is also interested in the supportive treatment of cancer patients including the use of acupuncture.
Diseases, Medical Tests and Treatments
Breast Cancer
Lung Cancer
Mesothelioma
Breast Cancer
Lung Cancer
Mesothelioma
“Evidence-based care tailored to each patient — taking the time to explain options and shared decisions.”
— Dr Mary E R O'Brien
Education & training
-
2011–2017 MD · Medicine and Surgery
-
2017–2021 Residency · Oncology
-
2021–2022 Fellowship · Subspecialty training
Career & appointments
-
2021-09–2022-08 Junior consultant
Licenses & insurance
Medical licenses
GB — Organización Médica Colegial de España (OMC)
Board certifications
European Board of Oncology
Malpractice insurance:
Generali Healthcare · 1,000,000 EUR coverage · No claims on file
Procedures performed
| Procedure | Code | Lifetime count |
|---|---|---|
| GP consultation | 99213 | 1,325 |
| Annual physical exam | 99395 | 2,227 |
| Vaccination administration | 90471 | 195 |
| Minor procedure (skin) | 17110 | 708 |
Services & pricing
| Service | Duration | Modality | Price |
|---|---|---|---|
| New patient consultation (60m) | 60 min | in_clinic|telemed | 180.00 EUR |
| Follow-up consultation (30m) | 30 min | in_clinic|telemed|phone | 90.00 EUR |
| Vaccination administration | 90 min | in_clinic | 810.00 EUR |
| Minor procedure (skin) | 60 min | in_clinic | 540.00 EUR |
Office, team & in practice
Videos
Research & publications
h-index: 17 · i10: 10
-
Outcomes of Oncology in adults — a multi-centre cohort
DOI: 10.3920/euroclin.2025.0 · PMID: 33768760 · cited by 189
-
European registry analysis of Oncology outcomes
DOI: 10.1360/euroclin.2024.1 · PMID: 34440021 · cited by 191
-
Outcomes of Oncology in adults — a multi-centre cohort
DOI: 10.4872/euroclin.2023.2 · PMID: 35817662 · cited by 9
Invited talks
- Practical updates in Oncology European Annual Congress (Oncology) · Vienna · 2024 · invited
- Single-centre experience in Oncology National Society Meeting · London · 2023 · oral abstract
Awards & memberships
Awards
- 🏆 Top-rated Oncology — London · EuroClinics Patient Choice · 2025 · regional
Society memberships
- WONCA Europe — Family Doctors — Member · Since 2022
- national college of family doctors — Member · Since 2022
- European Union of Medical Specialists (UEMS) — Member · Since 2022
Articles by this doctor
- Patient education Patient guide to Oncology
- Awareness When should you see a oncology?
For international patients
- Coordinator
- Patient liaison · prof.mary.obrien.1@euroclinics.example
Location
1 tagPatient reviews
Share your experience — help other patients find the right doctor. Write a review →
Recent reviews
-
★★★★★ ✓ Verified Very thorough first visit — explained every step. Booking was easy and the staff were welcoming.
-
★★★★★ ✓ Verified Took time to listen and reviewed all my previous results. I would absolutely recommend.
-
★★★★☆ ✓ Verified Professional and knowledgeable. Wait on the day was a bit long, otherwise excellent.
