What is a Medical Oncologist?

What is a Medical Oncologist?

Board-Certified Medical Oncologist

The Physician who specializes in the diagnosis and treatment of all types of cancers, as well as all tumors, whether malignant or benign

An Oncologist is a Board-Certified Doctor who completed residency training in Internal Medicine, followed by advanced training in the diagnosis and medical treatment of all types of cancers or tumors, benign and malignant. These are diseases caused by unregulated and potentially invasive growth of abnormal and genetically damaged cells. Benign tumors are growths that can grow locally and be destructive, but generally do not metastasize or spread and are rarely life threatening. In contrast, because of their ability to spread, malignant cancers are potentially life threatening and require immediate medical attention. Another distinction is that after benign tumors are removed, they usually do not recur, while malignant tumors can. Medical oncologists have specialized expertise in addressing recurrent cancers as well.

Medical Oncologists are the experts in identifying and staging cancers and they design and administer chemotherapy treatment plans for all types of cancers. They may work in consultation with surgical oncologists and radiation oncologists in cases of advanced or invasive disease that may have spread to remote parts of the body or invaded nearby organs and tissues.

The level of expertise and specialization in treating a particular condition as well as the credentials and practice style are important factors in choosing the right oncologist.

Your primary physician (Internal Medicine or Family Medicine) will refer you to a medical oncologist in the event of a cancer diagnosis, or may even refer you for preventive measures and/or to rule out any suspicion of cancer. In choosing an oncologist, you may do your due diligence and check his/her credentials and practice style with the help of your family and friends. You can also review their profile in myDoqter to learn about their training, credentials and even read the recommendations from other physicians who know first-hand the expertise and clinical competency of your oncologist.

Oncologists have completed M.D. or D.O. degrees and have advanced residency and fellowship training. The following representation illustrates the years of education and training that an Oncologist has undergone.

Origins of the word ONCOLOGY

ONCO from the Greek root ‘óngkos’ for ‘burden, volume or mass’ + LOGY from the Greek word ‘logia’ which means ‘logic’ or ‘the study of’.

Medical Oncologists treat an extensive number of various types of tumors and cancer-related conditions, including:

Acute Lymphocytic Leukemia: also known as ALL, is a blood and bone marrow cancer that affects white blood cells. When white blood cells proliferate abnormally, they become leukemia cells that can accumulate in the bone marrow and affect normal cell growth. They can also travel through the bloodstream and rapidly spread and affect other organs. Associated symptoms may include enlarged lymph nodes, bruising, fever, bone pain, bleeding from the gums, and frequent infections.

Acute Myelogenous Leukemia: also known as acute myeloid leukemia or AML, is a blood and bone marrow cancer that initially starts in the bone marrow due to an excess of immature white blood cells, but has the ability to spread.ociated symptoms may include fatigue, recurrent infections, and bruising.

Aplastic Anemia: is a bone marrow disease in which there is an unexplained failure of the bone marrow to produce blood cells of any type. It is believed to be autoimmune in some cases. Associated symptoms include, fatigue, frequent infections, rapid heart rate, and unexpected bleeding.

Basal Cell Nevus Syndrome: also known as Gorlin syndrome, is a rare genetic condition that affects the skin, endocrine system, nervous system, eyes, and bones which may lead to the formation of benign and malignant tumors.

Bile Duct Cancer: also known as cholangiocarcinoma, is the most common form of primary liver cancer and that develops in the bile ducts - the slender tubes that carry the digestive fluid (bile) through the liver.

Bladder Cancer: is a malignant tumor of the bladder, the muscular organ that collects and stores urine from the kidneys and that sits just above the pubic bone. It may present with symptoms that include painless blood in the urine or frequent and painful urination.

Bone tumors: are masses of abnormally growing cells derived from the bone. They may be due to abnormal healing of after an injury, inherited conditions, radiation therapy, or cancer.

Brain Tumors: present as a benign or malignant mass due to abnormal cell growth in the brain. Associated symptoms include neurologic symptoms such as new or increasingly strong headaches, blurred vision, loss of balance, confusion, and seizures.

Breast Cancer: are malignant cell transformations that produce tumors in the breast. They are more common in women, but can occur in men as well. Breast cancer may present as a lump in the breast, bloody discharge from the nipple, or more superficial changes in the shape or texture of the nipple or breast skin.

Cervical Cancer: is a malignant tumor in women that is derived from the lowermost part of the uterus, or womb. It is often due to the presence of high-risk strains of HPV (human papillomavirus), a common sexually transmitted infection. 

Colorectal Cancer: is a gastrointestinal cancer of the colon or rectum, located at the lower end of the digestive tract.

Cutaneous T-Cell Lymphoma: also known as CTCL, is a rare type of cancer that is caused by abnormalities in white blood cells called T cells (T lymphocytes). These are important white blood cells that normally help your body fight immune conditions, but they hone in and attack the skin in CTCL.

Endometrial Cancer: is a gynecologic cancer that begins in the inner lining of the uterus or womb in women. The inner lining of the uterus is called the endometrium.

Ewing Sarcoma: is a rare malignant cancerous tumor that grows in the bones or in the soft tissue around bones. Common sites for this tumor include the legs, pelvis, ribs, arms or spine.

Glioma: is a central nervous system (CNS) type of tumor that occurs in the brain and/or in various locations in the nervous system such as the brain stem and spinal column.

Head & Neck Cancers: are tumors that originate in the mouth, nose, sinuses, salivary glands, throat, and lymph nodes. Associated symptoms may include ear pain, a growing neck mass, shortness of breath, weight loss, and a hoarse voice.

Hematologic Cancers: are commonly known as blood cancers and begin in blood-forming tissue, such as the bone marrow or in the cells of the immune system where red blood cells and white blood cells travel.

Kidney Cancer, or renal cell carcinoma: is a malignant cancer derived from the lining of tiny tubes inside the kidneys that are responsible for filtration and generation of urine.

Leukemias: are cancers that involve abnormal and malignant cell formation and proliferation of the blood cells. They are considered a sub-category of hematologic cancers and may affect routine white and red blood cell functioning.

Liver Cancers: are tumors that start from the internal liver cells called hepatocytes or from the bile ducts of the liver. Although they may have a variety of causes, they may be associated with hepatitis infections, such as Hepatitis C.

Lung Cancers: are a group of cancers that begin in the lungs and are associated with smoking as a risk factor, whether from a primary smoker or from second-hand smoke.

Ocular (Eye) Melanoma: is a type of melanoma that develops from the pigment producing cells in the retina of the eye.

Oral Cancer: also called oral cavity cancer, is a type of cancer that develops in any part of the mouth or oral cavity. Associated symptoms can include a sore that doesn't heal, a lump, or a white or red patch on the inside of the mouth.

Osteosarcoma: is a type of bone cancer that begins in the cells involved in bone formation and results in the production of immature bone growths that are often associated by localized bone pain and swelling.

Ovarian Cancer: is a gynecologic cancer that begins in the ovaries, the female organs that produce eggs as well as the hormones estrogen, progesterone, and testosterone.

Pancreatic Cancer: is a disease in which malignant (cancerous) cells form in the tissues of the pancreas, a gland located behind the stomach, that produces digestive juices and hormones that regulate blood sugar.

Parathyroid Cancer: is a rare disease of the parathyroid gland, an organ located in the throat area that is important in the regulation of blood calcium levels. Symptoms can include bone pain, fatigue, lump in the neck and/or frequent thirst.

Prostate Cancer: is a type of cancer found in the male prostate gland, a small walnut-shaped gland in men that produces the seminal fluid that nourishes and transports sperm. A common presenting feature of this type of cancer is difficulty urinating.

Skin Cancers: are the result of abnormal cell growth, most commonly arising in the top layer of the skin, known as the epidermis. It is caused in part by unrepaired DNA damage that prompts mutations leading the skin cells to rapidly multiply and form malignant cancers. There may be a genetic or familial tendency to develop skin cancers. The main types of skin cancer are basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM) and Merkel cell carcinoma (MCC).

Stomach Cancer: medically known as gastric cancer, originates from the cells that form the inner lining of the stomach. Presenting symptoms may include unexplained persistent nausea, stomach pain or chronic ulcers, persistent vomiting and/or unintentional weight loss.

Testicular Cancer: is a type of cancer derived from abnormal cell growth in the testicles, the male organs that generate male hormones and sperm. Associated symptoms include a lump in either testicle and a feeling of heaviness in the scrotum.

Throat Cancer: is a cancer of the larynx, or voice box, that is located in the neck region.

Thyroid Cancer: is a tumor of the thyroid, the butterfly-shaped gland at the base of the neck. It may present with a swelling or lump in the neck called a goiter. Other associated symptoms may include hoarseness or trouble swallowing.

Ultimately, healthy lifestyles and preventative measures offer the most cost-effective long-term strategy for the fight against cancer. This includes age-appropriate cancer screenings as advised by the American Cancer Society, in accordance with age and risk factors.

For example, because breast cancer is the most dominant type of cancer in the U.S., the American Cancer Society recommends that women 45 to 49 years old should get mammograms yearly, and leave an open option for women ages 40 to 44 to start annual breast cancer screening with mammograms if they wish to do so.

When you visit your Oncologist, you will also receive other important information regarding ways to reduce risk factors to prevent certain cancers. Important topics may include:

  • smoking cessation
  • increased physical activity and exercise
  • adopting a healthy and balanced diet
  • adequate daily sleep
  • reduction in alcohol consumption
  • boosting your immune system with the help of vitamins and nutrients
  • limiting environmental carcinogens exposure
  • avoid unnecessary ionizing and ultraviolet radiation with proper sunscreen use.

Your Oncologist may offer you a wide range of treatment choices and approaches to treat a specific cancer or malignant tumor. They will work with you to find the best personalized treatment option and approach for your specific condition. Make sure to discuss all these options and other preventive measures with your primary care physician and seek the care of a medical oncologist if necessary.


You can read more about Medical Oncology in the following links:


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