just reading about carcinoma and sarcoma... I am wondering why it is that sarcomas are so much rarer than carcinomas?
any ideas are much appreciated!!
- Thread Starter
- 25-08-2016 16:36
- 29-08-2016 09:29
Epithelial tissues generally have a higher turnover rate and act as a protective barrier within the body. Increased division and exposure to carcinogens would increase the chance of malignant transformation.
Carcinomas of the bladder and oral cavity are good examples of this, in smokers (not exclusively, but it's a fair example as smokers are ~40% more likely to develop carcinoma) both the mouth and the bladder are exposed to increased amounts of carcinogens, the transitional epithelium in the bladder is continually regenerating as is the oral epithelium. Injury through exposure to irritants or mechanical damage can allow mutagens to access developing cells in the underlying epithelium, even effecting basal cells, which are stem-like (this can be the cause of the most recurrent carcinomas).
Whereas with sarcomas, let's take of cartilage for example, there is limited blood supply - if any. Without blood carrying mutagens to the site the likely cause is hiertitary or idiosyncratic. Cartilage is also very slowly dividing, and has a low regenerative capacity under normal conditions.
Hope this helps!