Should Cancers Nomenclature Mirror Embryology, or is that 1880 Thinking?

 You’ve said that various leukemias are related to earlier or later stages of B cells.  

Is this a theory that cancers like leukemias recapitulate embryology?  Are there debates or pro’s and con’s to that view?  I thought cancers were caused by a translocation, fusion, or oncogene.

ChatGPT

It's true that leukemias and lymphomas often resemble cells at different stages of B or T cell development, and this is a well-recognized concept in the field of hematology and oncology. This observation is not so much a recapitulation of embryology, as it is a reflection of the cell of origin of the cancer. The type of leukemia or lymphoma often reflects the stage at which a normal cell acquired a critical mutation and began its uncontrolled growth.

The concept of cancers "recapitulating embryology" is more about the idea that cancers can gain characteristics of more "primitive" cells - for instance, they may gain the ability to proliferate indefinitely, escape normal growth controls, and invade surrounding tissues, much like embryonic cells. However, it's important to clarify that cancer cells do not actually become embryonic cells, but rather gain some properties of these cells due to mutations.

In terms of the cause of cancers, it's true that translocations, fusions, or oncogenes can contribute to the development of cancer. However, these are not the only factors. Cancers, including leukemias and lymphomas, are usually the result of an accumulation of several genetic changes over time. These changes can include point mutations, deletions, amplifications, translocations, and other forms of genomic instability.

Furthermore, not all cancers are driven by the same types of genetic alterations. For instance, some leukemias are characterized by specific chromosomal translocations (like the BCR-ABL fusion in chronic myeloid leukemia), while others may be driven by point mutations in specific oncogenes or tumor suppressor genes. It's also important to note that these genetic changes alone are often not sufficient to cause cancer, and other factors like the cellular and tissue microenvironment, immune system interactions, and lifestyle factors can also play a role.

 

There’s a brain tumor neuroblastoma and a glioblastoma, invoking neuroblasts and glioblasts.

ChatGPT

Yes, you're correct. Neuroblastoma and glioblastoma are types of brain tumors named after the types of cells from which they are believed to originate.

Neuroblastoma: This is a type of cancer that most often affects children, usually under the age of 5. The term "neuroblastoma" comes from "neuro" (referring to nerves) and "blastoma" (indicating immature cells). It originates in neuroblasts, which are immature nerve cells present during fetal development. These cells usually mature into functioning nerve cells, but in neuroblastoma, they become cancerous. The most common location for neuroblastoma is the adrenal glands, but it can also develop along the spine, chest, abdomen, or pelvis—anywhere along the sympathetic nervous system.

Glioblastoma: This is a very aggressive type of cancer that can occur in the brain or spinal cord. Glioblastoma forms from cells called astrocytes that support nerve cells. The term "glioblastoma" comes from "glia" (referring to the glue-like function of astrocytes) and "blastoma" (referring to immature cells). This type of tumor is most common in adults and is known for its fast growth rate due to a rich supply of blood vessels in the brain. It's also highly resistant to conventional therapies, which makes its prognosis quite poor.

In both cases, the names of the cancers reflect the type of cells that they originate from (or closely resemble), rather than the cells they mature into. So, the "blastoma" in both names refers to the immature or precursor nature of the cells that give rise to these cancers. This reflects the idea that cancers often resemble (and are named after) the cell of origin, rather than the mature cell type that they may otherwise have developed into.

User

Could a respected cancer scientist argue that such terms are leftovers from the 1880’s and not really helpful for 21st century medical therapy ?

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Yes, a respected cancer scientist could argue that terms like "neuroblastoma" and "glioblastoma" are somewhat outdated and may not fully capture the complexity and diversity of these tumors in the context of 21st-century medical therapy. With advancements in molecular biology, genomics, and personalized medicine, our understanding of cancer has evolved significantly since the 19th century.

In recent years, researchers have discovered that cancers with similar histological appearances (i.e., what they look like under the microscope) can have vastly different molecular profiles, which can influence their response to treatment and prognosis. As a result, the classification of cancers based solely on their cell of origin or microscopic appearance may not provide enough information for optimal patient management.

For example, glioblastomas are now known to have different molecular subtypes, such as those with IDH1/2 mutations and those without. These molecular subtypes have different prognoses and may require different treatment strategies. A more modern classification system could incorporate molecular information to better guide treatment decisions.

It's worth noting that the World Health Organization (WHO) updates its classification of tumors (including brain tumors) periodically to reflect advances in our understanding of cancer biology. The most recent edition (the 5th edition, published in 2021) incorporates molecular information alongside histological features to classify tumors more accurately.

While the traditional terms like "neuroblastoma" and "glioblastoma" are still in use, they are increasingly being supplemented by additional molecular information to ensure that patients receive the most appropriate and effective treatment. The field of oncology continues to evolve, and it is likely that the terminology and classification systems will be updated and refined as new discoveries are made.

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I have a book about brain tumor classification from the 1920s.  There have been huge changes, including by the 1990s when I was in training.   A few terms are carried forward, but the meaning of the term may have changed a great deal.  In other cases, 1920s terms have fallen into disuse, yet the cancers the term referred to must still exist.   It would be interesting for someone to study the changes in tumor nomenclature decade by decade 1880s to 1980s.   

(FERGUSON in 2005 wrote about BAILEY and his era - 

https://pubmed.ncbi.nlm.nih.gov/15844870/)

ChatGPT

Your observation is spot on. The evolution of medical terminology, particularly in the field of oncology, reflects the advancement in our understanding of diseases. It would indeed be a fascinating study to trace how the nomenclature of tumors has changed over the decades.

In the late 19th and early 20th centuries, tumors were generally named based on their appearance under a microscope, relating to the type of cell or tissue they seemed to resemble. As you mentioned, many of these terms are still in use today, although their precise definitions may have evolved or even shifted substantially as our understanding of cancer biology has progressed.

With the advent of molecular biology and genetics in the latter half of the 20th century, researchers started to realize that cancers with similar histological appearances could have very different behaviors and responses to treatment due to underlying genetic differences. This has led to the incorporation of molecular and genetic information into cancer classification, a trend that continues in the current era of precision medicine.

Studying the changes in tumor nomenclature over time would provide interesting insights into the history of oncology and the progression of scientific knowledge. It could also reveal trends and shifts in research focus, as well as highlight the influence of technology on the field. Such a study would not only be of historical interest but could also inform the development of future classification systems and the direction of cancer research.

User

It would also humble us that whatever terms and ideas we use today, in 40 years they will be antique-sounding.

ChatGPT

Absolutely, the rapid pace of scientific and medical research means that our current understanding and terminology will almost certainly evolve and may indeed seem outdated in a few decades. This perspective emphasizes the continuous nature of scientific discovery and medical progress.

In fact, this continual evolution is one of the great strengths of science. As we gather new data, refine our methodologies, and develop new technologies, we are able to reassess and refine our theories, models, and classifications to improve our understanding of the world, including complex diseases like cancer.

However, while the specifics may change, the core principles and objectives of medicine—to reduce suffering, to treat disease, and to improve quality of life—remain constant. So even as we look forward to future advancements, we can also appreciate the knowledge and tools we have today, recognizing that they represent the current state of a long and ongoing journey of discovery and improvement.

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I was thinking of an old book, I think 1920s, by Percival Bailey.  I found a biographical article about him,  Neurosurg Focus . 2005 Apr 15;18(4):e7. doi: 10.3171/foc.2005.18.4.8.

Percival Bailey and the classification of brain tumors

Sherise Ferguson 1, Maciej S Lesniak

Affiliations expand

PMID: 15844870 DOI: 10.3171/foc.2005.18.4.8

Abstract

Throughout his illustrious career, Percival Bailey made numerous contributions to the fields of neurology, neuroanatomy, psychiatry, neuropathology, and, of course, neurosurgery. His expertise, his curiosity about the nervous system, and his desire to examine it from all angles were unique. With the exception of Harvey Cushing, Dr. Bailey made some of the greatest contributions in the area of neuro-oncology at the turn of the last century. In this essay the authors summarize the key episodes of Bailey's life and discuss his impact on the classification and treatment of human brain tumors.

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ChatGPT

Dr. Percival Bailey (1892–1973) was indeed a significant figure in the history of neuro-oncology. Alongside Dr. Harvey Cushing, he was instrumental in the development of a classification system for brain tumors.

Bailey and Cushing's classification system, first published in 1926, was based on the idea that brain tumors could be classified according to the cell type they most closely resembled, under the assumption that this was their cell of origin. This idea was groundbreaking at the time and formed the basis of our understanding of brain tumors for many years.

Bailey's work extended beyond classification, and he was also noted for his surgical techniques and for his exploration of the relationship between brain structure and behavior. However, his contributions to the classification of brain tumors remain perhaps his most enduring legacy in the field of neuro-oncology.

As our understanding of brain tumors has advanced, the classification system has been revised and updated, with molecular markers now playing a significant role in tumor classification. Despite these changes, the work of Bailey and Cushing remains foundational to our understanding of brain tumors.

Your interest in this historical aspect of neuro-oncology seems quite keen. The study of how such classifications have evolved over the years can provide us valuable insights into the progress of medical science and might even guide future research and therapeutic strategies.