As I mentioned in this post about Childhood Cancer Awareness Month and CURE Childhood Cancer, September is a busy month in terms of cancer awareness. While I consider myself primarily a breast cancer activist, I recognize that at the heart of every type of cancer is the same thing: formerly normal cells behaving badly, growing out control, and becoming malicious. To that end, I think that any type of cancer activist should take some time to familiarize themselves with the other major types of cancer that exist in the world and take innocent lives every day. Because today is officially World Lymphoma Awareness Day, and because the rest of the month of September is more broadly recognized as Blood Cancer Awareness Month, I thought today was a great day to write a little more about blood cancers.
Two Important Stats About Blood Cancers Worth Knowing
- Someone in the United States is diagnosed with a blood cancer every four minutes. (per the Lymphoma Research Foundation)
- Blood cancer is the third leading cause of cancer death in the US. (per the Leukemia and Lymphoma Society)
Did you know those stats? Until I started researching this post, I didn’t. I guess this is one cancer awareness month that I really need!
Blood cancer as a group is actually made up of three major types of cancer: leukemia, lymphoma, and myeloma. Each of these cancers begin as a different type of white blood cell that ultimately begins accumulating at an above normal rate, either due to increased cell production or decreased cell death. As a result of this rapid accumulation, those cells quickly become abnormal, resulting in different types of cancer, depending on the type of cell the cancer originated as. Because each of these types of cancer are such different diseases, I’m going to talk about each of the major types of blood cancer individually.
Leukemia is a type of cancer that starts in the bone marrow, the site of blood cell production in the body. There are three primary types of blood cells that the body produces: red blood cells (or “erythrocytes”, the cells that carry oxygen to the rest of the body), white blood cells (or “leukocytes”, which fight infection in the body), and platelets (which are responsible for clotting). In general, leukemia is the type of cancer that arises when the body accumulates cancerous leukocytes/white blood cells, or WBCs, as I’m going to abbreviate them here on out.
[Science reading comprehension tip: The prefix leuk- is derived from latin word for white, and in science/medical parlance, generally refers to white blood cells. Any term that ends in the suffix “-cyte”, is a specific type of cell. Therefore, a leukocyte is literally a white blood cell. The suffix -emia is used when referring to anything blood-related. So a blood cancer of white blood cells = leukemia.]
The body makes a huge number of different WBCs, each of which performs a different role within the circulating immune system. WBCs develop from one of two types of stem cells, depending on which type of WBC they are meant to become: myeloid stem cells (which are also the precursor cells to red blood cells and platelets) or lymphoid stem cells. Leukemias can develop from either of these stem cell types. Based on the type of stem cell that the cancer developed from and the rate at which the cancer progresses, the majority of leukemias can be classified as one of four types:
1. Chronic Lymphocytic Leukemia (CLL) – leukemia originating from lymphoid stem cells that progresses slowly. CLL affects primarily adults.
2. Chronic Myeloid Leukemia (CML) – leukemia originating from myeloid stem cells that progresses slowly. CML also affects primarily adults.
Chronic leukemia cells usually retain some degree of functionality as WBCs, at least at the beginning of the disease. Because of this, the decline in health of individuals with chronic leukemias is relatively slow. As a result, chronic leukemias can be more difficult to diagnose.
3. Acute Lymphocytic Leukemia (ALL) – leukemia originating from lymphoid stem cells that progresses rapidly. ALL is the most common leukemia in children, although it is also found in adults.
4. Acute Myelod Leukemia (AML) – leukemia originating from myeloid stem cells that progresses rapidly. AML affects both kids and adults.
Acute leukemia cells cannot function as normal WBCs, leading to a rapid decline in health for those with these types of cancer.
CLL is the most prevalent type of leukemia (accounting for approximately 15,000 new cases of leukemia per year). AML accounts for approximately 13,000 new cases of leukemia per year, while CML and ALL each account for about 5,000 new cases of leukemia per year. Other minor subtypes of leukemia also exist, and together they account for approximately 6000 new cases of cancer per year. Ultimately, it is predicted that 47,150 new cases of leukemia will be diagnosed in 2012 and 23,540 people will die from the disease. One in 74 people will be diagnosed with leukemia in their lifetimes. It is also worth noting that while leukemia affects 10x more adults than children, it is still the most common cancer diagnosed in children. In the US, we spend approximately $4.5 billion treating leukemia every year.
The National Cancer Institute (who was my source for all of this information) allocates approximately 4.7% of it’s annual budget (or $239.7 million) for leukemia research in 2010, the last year for which that information was available.
The information in this section was provided to the public courtesy of the NCI. You can find more information about leukemia in their “What You Need to Know About Leukemia” booklet, here and in their “Leukemia Snap Shot” report, here. All of the stats came from the Surveillance Epidemiology and End Results (or SEER) fact sheet on leukemia, here.
Whereas leukemias originate from stem cells located in the bone marrow, lymphomas are cancers that arise from lymphoid stem cells that are found in the lymphatic system. The lymphatic system (which is part of the body’s large immune system) includes lymphocytes (a specialized subtype of WBC), the lymph vessels (found throughout the body), the lymph fluid, and the lymph nodes, which connect the various lymph vessels and act as something of a filtration system to keep the lymph fluid clear of bacteria and other infectious agents.
There are two major types of lymphomas, and further subtypes of each of those:
1. Hodgkin’s lymphoma, which is distinguished by the presence of a specific type of cancer cells called Reed-Sternberg cells. Hodgkin’s lymphoma can be further classified as either the more common classical subtype of Hodgkin’s lymphoma or the comparatively more rare nodular lymphocyte-predominant Hodgkin’s subtype.
2. Non-Hodgkin’s lymphoma, which is defined as any lymphoma that lacks Reed-Sternberg cells. There are many subtypes of Non-Hodgkins lymphoma based on the rate of progression of the disease (generally defined as either aggressive or indolent/slow), the original lymphocyte subtype that the cancer developed from, and other cellular characteristics.
Lymphomas account for 5% of all cancers in the United States, with Non-Hodgkins lymphoma being far more prevalent than Hodgkins lymphoma. It is estimated that in 2012, 70,130 will be diagnosed with Non-Hodgkins lymphoma and 9,060 will be diagnosed with Hodgkin’s lymphoma. Further, it is estimated that 18,940 people will die from Non-Hodgkins lymphoma and 1,190 people will die from Hodgkins lymphoma this year. One out of every 47 people will be diagnosed with Non-Hodgkins lymphoma and one out of every 436 people will be diagnosed with Hodgkins lymphoma in their lifetimes. In the US, we spend approximately $10.2 billion annually treating lymphoma.
NCI allocated 2.7% of its annual budget (or $137.0 million) in 2010 for lymphoma research.
The information in this section was also provided to the public courtesy of the NCI. You can find more information about lymphoma in their “What You Need to Know About Hodgkins Lymphoma” and “What You Need to Know About Non-Hodgkins Lymphoma” booklets, here and here, respectively. Additional information can also be found in their “Lymphoma Snap Shot” report, here. All of the stats came from the SEER fact sheets on Hodgkins and Non-Hodgkins leukemia, here and here, respectively.
Myeloma (or plasma cell myeloma as it is also known) is a type of blood cancer that originates specifically in the plasma cells. Plasma cells are a highly specialized type of white blood cell that produces antibodies. When the disease first develops, myeloma cancer cells accumulate specifically within the bone marrow, much like with leukemia. As the disease progresses, myeloma cells accumulate in multiple bones simultaneously, at which stage the disease is described as Multiple Myeloma.
Myeloma is the second most common blood cancer and accounts for 1% of all cancers in the United States. It is estimated that 21,700 people will be diagnosed with myeloma in 2012 and that 10,710 people will die from the disease in this same time frame. One in 150 people will be diagnosed with myeloma in their lifetime. NCI did not report an estimate for aggregated annual treatment costs to the country for myeloma.
NCI allocated approximately 1% of it’s annual budget (or $48.5 million) in 2010 for myeloma research.
The information in this section was also provided to the public courtesy of the NCI. You can find more information about myeloma in their “What You Need to Know About Multiple Myeloma” booklet, here. Additional information can also be found in their “Myelnoma Snap Shot” report, here. All of the stats herein came from the SEER fact sheet on myeloma, here.
If you would like to learn more about blood cancer in general, or one of these types of cancers in particular, I highly recommend reading through the NCI’s web pages dedicated to leukemia, Non-Hodgkins lymphoma, Hodgkin’s lymphoma, and Multiple Myeloma. The “snap shot” reports linked to in each subsection are particularly informative, especially the sections discussing recent research investments and findings.
The American Cancer Society also has the following subsections of their “Learn About Cancer” webpage dedicated to blood cancers:
- Hodgkin Disease
- Leukemia – Acute Lymphocytic (ALL) in Adults
- Leukemia – Acute Myeloid (AML)
- Leukemia – Chronic Lymphocytic (CLL)
- Leukemia – Chronic Myeloid (CML)
- Leukemia – Chronic Myelomonocytic (CMML)
- Leukemia in Children
- Multiple Myeloma
- Non-Hodgkin Lymphoma
- Non-Hodgkin Lymphoma In Children
The American Association for Cancer Research also recommends the following blood cancer advocacy and patient support organizations:
- The Leukemia and Lymphoma Society
- The Lymphoma Research Foundation
- The International Myeloma Foundation
- The Multiple Myeloma Research Foundation
Finally, to learn more about the origins of World Lymphoma Awareness Day, please visit The Lymphoma Coalition.
Image source – Thanks for letting me borrow it!
Note: While I am a biomedical scientist, I am not considered an expert (medical or otherwise) on any of these types of cancer. This post, as with future planned “awareness month” posts, is not meant to be an in depth review of these types of cancer. Rather, I only wanted to provide a brief overview of each type of cancer in the blood cancer family in order to help further the larger cancer community’s awareness of each of these cancers. Moreover, while I provided links to a number of blood cancer organizations at the end of this post, I have not researched these organizations to the extent that I do for my “Spotlight On” series of posts. Until I can research them further, I am not explicitly advocating financial donations to these organizations (although I certainly won’t advise you against it either should you find them worthy!). Instead, I am recommending them here because each organization is a well respected leader in these specific areas and is considered a reputable source for further information on blood cancers.