Cancer, Part 3 – Different Types of Cancer

There are over 100 types of cancer consisting of a variety of cell types arising from every tissue in the body. Some organs, for example the lung, may have cancerous tumors of a variety of cell types. Even the cell types can be subdivided according to their degree of differentiation, from very immature (anaplastic) to more highly differentiated. There are grading systems describing how invasive the cancer has become, including whether it has metastasized to other parts of the body. Below are the most common organs from which cancer cells are derived.

• Breast cancer accounts for about 15% of malignancies and is the most common cancer in women. Because many cases are cured or are associated with prolonged remission, breast cancer accounts for only 7% of cancer deaths in adults.
• Prostate cancer is about as common as breast cancer, accounting for about 15% of cancer cases. It is not among the most common causes of death due to cancer in men – a large percentage of men with prostate cancer die from other causes, since they are either cured with surgery and other modalities or live with this cancer for a long period of time.
• Lung cancer represents about 12% of cancer cases in adults. Because it is one of the most lethal types of cancer, it accounts for more than 20% of cancer deaths. Smoking is the primary cause of lung cancer, though not all lung cancers occur in smokers.
• Colon and rectal cancer represent 8% of cancer diagnoses but account for a slightly higher percentage of cancer deaths because they are often discovered after having metastasized.

The causes of cancer in children are very different than in adults. The most common cancers in children by far are the acute lymphoblastic and myeloblastic leukemias (ALL and AML, respectively – cancers of white blood cells in the bone marrow) and lymphoma (cancer of the immune system arising outside the bone marrow). Brain and other central nervous system malignancies are also much more common in children than adults. 

• Leukemias account for about 28% of all malignancies in children. Acute leukemias are much more common than the chronic forms seen in adults. Acute lymphoblastic leukemia is #1 in incidence and, fortunately, rate of cure. AML is less often cured in older children but has higher success rates in infants and toddlers. These cancers grow quickly and chemotherapy must be started as soon as the specific diagnosis is made. They often present with fatigue, bone and joint pain, pale skin, bleeding or bruising, fever, and weight loss.
• Brain and spinal cord tumors comprise about 26% of childhood cancers. They oftenoccur in the lower part of the brain, the cerebellum and brainstem. Children present with headaches, nausea and vomiting, visual changes, seizures, trouble walking, and other signs. They are too often fatal despite surgery, chemotherapy, and radiation therapy.
• Lymphomas make up about 8% of childhood cancer. They start with mutations in lymphocytes in lymph nodes, thymus, and spleen, for example. Non-Hodgkin’s lymphoma occurs in children mainly over the age of 3 years and require g treatment. Hodgkin’s lymphoma (or disease) in teens and young adults as well as adults over age 55. Hodgkin’s lymphoma has a 5-year rate over 90% and over 70% cure rate if treated early. Non-Hodgkin’s lymphoma has many sub-types most of which more difficult to eradicate and often recur after initial remission. Both most frequently present with fever, weight loss, and fatigue.

Other types of childhood cancer include neuroblastoma, which often starts in the abdomen in infants and young children, and Wilms tumor, which arises in the kidney. Like most tumors, prognosis depends on how early the cancer is treated. 

Even as treatment for most cancers continues to improve, there has been a dramatic rise in cancer incidence in people under 50 years of age. Contributory factors appear to include early alcohol consumption, sleep deficiency, obesity, smoking, and diet, including lots of processed foods and sugary drinks. These risk factors have become more prevalent in children in recent years, certainly contributing to cancer risk in adulthood. Since diet significantly affects our gut microbiome more cancers are related to our GI system. These are modifiable factors – we in America must dramatically improve our diets and lifestyle while learning methods to reduce stress. The latter suppresses our immune system and predisposes to cancer.

Note: Although I am a physician, the content in this article is not meant to diagnose, treat, cure or prevent illness or disease in the reader – it is for educational purposes only.

References

• Sampson K. Dramatic rise in cancer in people under 50. The Harvard Gazette, September 8, 2022. https://news.harvard.edu/gazette/story/2022/09/researchers-report-dramatic-rise-in-early-onset-cancers/
• Dome JS, Rodriguez-Galindo C, Spunt SL, Santana VM. Chapter 92: Pediatric solid tumors. In: Neiderhuber JE, Armitage JO, Doroshow JH, Kastan MB, Tepper JE, eds. Abeloff’s Clinical Oncology. 6th ed. Philadelphia, PA. Elsevier; 2020.