Final answer:
Tumor blood vessels are abnormal because the cancerous cells grow rapidly and disorganizedly, leading to changes in cell cycle regulation and the appearance of fetal cell markers. These alterations can lead to abnormal tissue invasion and metastasis.
Step-by-step explanation:
The abnormal blood vessels (BV) in tumors are a result of the rapid and disorganized growth typical of cancerous cells. Cancer or tumors are caused by cells that fail to regulate their cell cycle properly, leading to continuous multiplication and the potential to invade surrounding tissues or spread to other parts of the body (metastasis).
This unchecked growth is often due to genetic abnormalities that compromise cell cycle regulatory mechanisms or environmental factors that damage DNA. Additionally, tumor cells may express antigens or enzymes that are usually found in fetal cells rather than adult ones, such as a-feto-protein and a placental type of alkaline phosphatase in carcinomas, which can also contribute to the abnormal behavior of these cells.
For example, in cervical cancer, cells of the cervix grow abnormally and develop the ability to invade nearby tissues or spread to other parts of the body, affecting the normal function of blood vessels within the tissue. Furthermore, deviations in biomarkers like elevated levels of B-hCG, which normally should fall after successful treatment of a tumor, can indicate abnormalities such as an ongoing infection or recurrence of a tumor.