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About Dr. Mary O Brien

Conditions treated by Dr. Mary O Brien

A medical oncologist treats different types of cancer using different techniques like hormone therapy, chemotherapy, targeted therapy, or immunotherapy. A medical oncologist works with other specialists to design a treatment plan according to the type and nature of cancer, age of the patient, stage of cancer. They discuss cancer diagnosis with you, including the stage and type you have. They also assist you to manage the cancer symptoms as well as treatment side effects. The conditions that Dr. Mary O Brien treats are listed below:

  • Primitive Neuroectodermal Tumors
  • Oligodendrogliomas
  • Stomach Cancer
  • Lung Cancer
  • Skin Cancer
  • Pancreatic Cancer
  • Ependymomas
  • Oral or Mouth Cancer
  • Cervical Cancer
  • Metastatic Cancer
  • Breast and Prostate Cancer
  • Breast Cancer
  • Prostate Cancer
  • Colon Cancer
  • Brain Cancers- Astrocytoma
  • Colorectal or Colon Cancer
  • Certain Types of Cancer that have been Resistant to Chemotherapy and Radiation Treatment (e.g. Melanoma)
  • Brain Cancer
  • Mixed Gliomas
  • Ovarian Cancer
  • Rectal Cancer
  • Meningiomas

Signs and Symptoms treated by Dr. Mary O Brien

Cancer can cause different symptoms. However, most of these symptoms are often caused by illness, benign tumors, injury, or other problems. If you experience symptoms that do not disappear after some weeks, consult your doctor so that actual problems could be diagnosed and treated as soon as possible. Also, cancer doesn’t cause pain, so see a doctor even if you do not feel pain. If you have any of the below-listed symptoms, your primary care doctor may refer you to a medical oncologist:

  • Persistent, unexplained muscle or joint pain
  • Difficulty swallowing
  • Changes in bowel or bladder habits
  • Hoarseness
  • Persistent cough or trouble breathing
  • Persistent indigestion or discomfort after eating
  • Skin changes, such as yellowing, darkening or redness of the skin, sores that won't heal, or changes to existing moles
  • Unexplained bleeding or bruising
  • Fatigue
  • Weight changes, including unintended loss or gain
  • Persistent, unexplained fevers or night sweats
  • Lump or area of thickening that can be felt under the skin

Operating Hours of Dr. Mary O Brien

You can find Doctor Mary O Brien in the clinic/hospital from 11 am to 5 pm (Monday to Saturday). The doctor is not available on Sunday. Although the doctor is mostly available at the given time, call the doctor or his assistant to confirm his availability.

Popular Procedures performed by Dr. Mary O Brien

Some of the popular procedures that Dr Mary O Brien performs are:

  • Chemotherapy

A medical oncologist uses chemotherapy for cancer treatment. It uses a combination of drugs to kill the cancerous cells in the body and prevents them from growing further. While chemotherapy could require a single drug, this is also given along with other drugs. Hormone therapy is used for the treatment of cancer that uses certain hormones to grow. It is effective in treating prostate and breast cancers. Hormone therapy slows or stops the rapid growth of cancer that uses hormones to grow.

Qualification

  • MD

Work Experiences

  • Royal Marsden NHS Foundation Trust
  • Global Team of Board Certified Surgeons and Medical Specialists
  • Written Second Opinion report delivered within 5 days
  • Option to avail the Video Consultation with the Lead Doctor of the board

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Telemedicine Doctors

Dr. Amit Bhargava

Dr. Amit Bhargava

Oncologist

Delhi, India

23 Years of experience

USD 70 USD 60 for video consultation

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Dr. Priya Tiwari

Dr. Priya Tiwari

Medical Oncologist

Gurgaon, India

18 Years of experience

USD 57 USD 48 for video consultation

Book Video Consultation
Dr. Amit Updhyay

Dr. Amit Updhyay

Oncologist

Delhi, India

18 Years of experience

USD 57 USD 48 for video consultation

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Dr. Professor Han Baohui

Dr. Professor Han Baohui

Pulmonologist and Cancer Specialist

Shanghai, China

40 Years of experience

USD 700 USD 650 for video consultation

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MEMBERSHIPS (1)

  • Member, British Association for Cancer Research

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PROCEDURES

  • Adrenal Cancer Treatment
  • Chemotherapy
  • Cholangiocarcinoma (Bile Duct Cancer)
  • Malignant Mesothelioma Treatment
  • Nasopharyngeal Cancer Treatment
  • Papillary Thyroid Cancer Treatment
  • Rhabdomyosarcoma (RMS) Treatment
  • Small Intestine Cancer Treatment
  • Vaginal Cancer Treatment
  • Vulvar Cancer Treatment

FREQUENTLY ASKED QUESTIONS

What area of specialization does Dr. Mary O Brien have?
Dr. Mary O Brien is a specialized Medical Oncologist and is one of the most sought after doctors in London, United Kingdom.
Does Dr. Mary O Brien offer Telemedicine Consultation through Medigence?
No, this doctor does not offer telemedicine via MediGence
How many years of experience does Dr. Mary O Brien have?
Dr. Mary O Brien is one of the most sought after specialists in United Kingdom and has over years of experience.

FAQ's Related to Medical Oncologist

What does a medical oncologist do?

A medical oncologist treats cancer using different methods, such as biological therapies, chemotherapy, hormonal therapies, and other targeted treatments. People often consider medical oncologists as their primary cancer doctor. They also assist their patients to manage side effects, and they help monitor well-being. Very often, patients follow up with medical oncologists post-treatment. If a medical oncologist finds that cancer cannot be treated, they recommend hospice or palliative care for the patients. A medical oncologist is mainly involved to manage cancer.

What are the tests required before and during consultation by a medical oncologist?

A medical oncologist would suggest the below tests to be performed to diagnose cancer:

  • Biopsy
  • Imaging Tests
  • Physical Exam
  • Laboratory Tests
  • Cancer Screening

One of the most common test for cancer, biopsy is a sample of tissues extracted from a body part in order to examine it. A doctor recommends biopsy when a previous test suggests an area of tissues isn't normal.

When should you go to see a medical oncologist?

A person may be referred to a medical oncologist when the primary case doctor thinks that the person shows cancer symptoms. The medical oncologist evaluates the condition of the patient and examines to confirm cancer. You need to see a medical oncologist if you experience the symptoms listed below:

  1. Change in bowel or bladder habits
  2. Indigestion or difficulty swallowing
  3. Change in a wart/mole
  4. Nagging cough
  5. A sore throat
  6. Unusual bleeding or discharge
  7. Lump in the breast or elsewhere

Reviewer

Dr. Vijita Jayan
Dr. Vijita Jayan

BPT, MPT (Neuro)

18 Years of Experience

With over 18 years of distinguished clinical experience, Dr. Vijita Jayan is a highly accomplished Clinical Director and Rehabilitation Specialist, renowned for her expertise in neuro-rehabilitation, functional recovery, and mobility-dependent case management. Her extensive practical knowledge enables her to design and implement individualized, evidence-based rehabilitation protocols that consistently yield measurable patient outcomes. A prolific researcher and academic writer, she has authored numerous peer-reviewed articles and research papers, significantly advancing the field of rehabilitative medicine. The recipient of multiple prestigious accolades, Dr. Jayan is widely regarded as one of the foremost authorities in Physical Medicine and Rehabilitation, continually shaping neuro-rehabilitative care through research, innovation, and clinical excellence. View More

Last Reviewed - January 2026

Author

Dr. Shagufta Parveen
Dr. Shagufta Parveen

Doctor of Pharmacy

3 Years of Experience

Dr. Shagufta Parveen is a Clinical researcher and medical writer with expertise in clinical pharmacology and pharmacotherapeutics. She holds a B.Pharm and Doctor of Pharmacy (Post-Baccalaureate) degree from Teerthanker Mahaveer University, Moradabad.

During her clinical stint at BLK-Max Super Speciality Hospital and Indraprastha Apollo Hospital, she gained hands-on experience in the Clinical Pharmacology Department. Combining scientific knowledge with strong medical writing skills, Dr. Shagufta develops evidence-based healthcare content, treatment guides, and patient education resources.

Her work focuses on simplifying complex medical concepts while maintaining scientific accuracy, helping readers better understand healthcare advancements and treatment options.

In addition to her writing expertise, she is actively involved in scientific research and has contributed to peer-reviewed publications.

Her research work is accessible through the following links:

https://scholar.google.com/citations?user=lMVK1eIAAAAJ&hl=en

https://carcinogenesis.com/index.php/JOC/article/view/870

https://carcinogenesis.com/index.php/JOC/article/view/868

https://wjpsronline.com/abstract/0000000760

. View More