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Reviewed By Dr. Nishikubo

Hematology and oncology are two medical specialties that are often mentioned together, but they have distinct differences. If you have been referred to a hematologist or oncologist by a physician, you may be concerned about what this means.  The article below will help you better understand your referral, so you can make the best choice possible when seeking treatment.

How Hematology and Oncology are Related: Understanding the Differences

The main difference between hematology and oncology is that hematology is the study of the diseases related to blood, whereas oncology is the study of cancer. Hematology and oncology are two medical specialties that often intersect, leading to some confusion about their similarities and differences. In this article, we will delve into the world of hematology and oncology, exploring their definitions, focus, and areas of expertise. We will also examine the differences between these two specialties, highlighting the importance of understanding these differences for accurate diagnosis and treatment.

What is Hematology?

Hematology is the study of blood and blood-forming tissues. Hematologists focus on the diagnosis, treatment, and prevention of blood disorders and cancers of the blood, such as leukemia, lymphoma, and myeloma. Hematologists also treat non-cancerous blood disorders such as anemia, bleeding disorders, and blood clotting disorders.

What is Oncology?

Oncology, on the other hand, is the study of cancer. Oncologists focus on the diagnosis, treatment, and prevention of all types of cancer, including solid tumors and cancers of the blood. Oncologists use a variety of treatments, including chemotherapy, targeted therapies, radiation therapy, and surgery, to combat cancer.

Understanding the Differences Between Hematology and Oncology

While both specialties deal with cancer, there are some key differences between hematology and oncology.  Hematologists treat both benign blood conditions as well as blood and bone marrow cancers.  Oncologists, on the other hand, treat all types of cancer including blood and bone marrow cancers, but also solid tumors such as lung cancer, colon cancer and breast cancer.

  • Even though these two specialties have clear difference, many physicians tend to be board certified in both. 
  • Treatment approaches in hematology and oncology may differ.

Hematologists treat non cancerous blood conditions with medications, blood transfusions, and sometimes with bone marrow transplants, stem cell transplantation and other therapies.  Oncologists generally use a combination of treatments, such as surgery, chemotherapy, hormonal therapies, targeted therapies and radiation therapy, to treat cancer. Though hematologists and oncologists may use different treatments, there can also be some overlap in the treatments they use. For example, chemotherapy, targeted therapies and radiation are also used in management of blood cancers and solid tumors. 

Finally, the role of the physician in hematology and oncology differs. I would eliminate this whole section.  Actually, it is more often the oncologist who assumes a role as primary care physician for their patients who are undergoing treatment because of the unique side effects of therapy.  Hematologists tend not to assume that role, though both specialties are trained primarily in Internal Medicine then do a fellowship in Hematology and/or Oncology.  Radiation oncology is a completely different training path and medical oncologists are not radiation oncologists.  

Hematologists may work as general practitioners (or hematopathologists)(this is not correct.  Hematopathologists are pathologists who have additional training in hematopath), while oncologists typically work as medical or radiation oncologists. Oncologists may also work closely with other medical professionals, such as surgeons, to provide comprehensive cancer care.

Importance of Accurate Diagnosis

Understanding the differences between hematology and oncology is important for accurate diagnosis and treatment. Blood disorders and cancers can be complex, and require the expertise of specialists in these fields to provide the most effective care. By recognizing the unique focus and areas of expertise of hematologists and oncologists, patients can receive the most appropriate care for their specific condition.

In conclusion, while hematology and oncology share some similarities and many specialists in this area are board certified in both, there are significant differences between these two specialties. Hematology focuses on blood disorders and cancers of the blood, while oncology deals with all types of cancer. Treatment approaches and the roles of the physician also differ between these two fields. Understanding these differences is crucial for accurate diagnosis and for choosing the correct specialist to effectively treat blood disorders and cancers.

Carol Nishikubo MD

About Dr. Carol Nishikubo

Dr. Nishikubo has a particular interest in lung, breast, gastrointestinal and hematologic malignancies. Dr. Nishikubo has received numerous awards, honors, and recognitions, including Checkbook Top Doc, Super Doc, ACP Fellow, and more. She is active in several professional societies and serves on hospital committees at Providence Saint John’s Health Center and UCLA Medical Center, Santa Monica.