What Kind Of Cancer Is It When Colonoscopy Shows A Malignant Mass In Sigmoid Colon?
2. In general, a single change in an oncogene can result in tumor growth or cancer, while it takes two changes in tumor suppressor genes. How do you explain this difference? What do these genes code for normally? That is, in a healthy person, what role are the oncogenes and tumor suppressor genes playing, and how do they do it?
3. Hepatitis B, Hepatitis C, Human Papilloma Virus, Epstein-Barr Virus, Kaposi sarcoma-associated herpesvirus are all associated with cancer, and are all DNA viruses. Are these two facts incidental, or does one help explain the other? Another virus associated with cancer is HTLV (Human T cell leukemia-lymphoma virus), which is a retrovirus. How does this relate to the DNA viruses in the list? Why do only a small fraction of those infected with one of these viruses develop cancer?
4. Why do many chemotherapy patients lose their hair? What kinds of side effects are more likely in patients treated with monoclonal antibodies? What common chemotherapy side effects are not likely to be seen with monoclonal antibody treatment, and why?
5. Most cancers develop slowly, but progression of the disease seems to accelerate over time. What mechanisms can help explain this phenomenon?
Thanks for posting your query.
1. A malignant mass of colon which has invaded lymph nodes is most likely a stage II carcinoma. The exact staging can only be done after physical examination and whole body scan. Type of cancer can only be revealed in the biopsy report.
Malignant cells differ in appearance from the normal cells of body and are highly invasive.
2. In a normal person, tumor genes are not expressed and tumor suppressor genes are active. Whenever there is imbalance between these, tumor develops. This can also happen due to some mutations.
3. Viruses while replication viral genome connects to the human genome and some of these induce changes in the human genome inducing the carcinogenic changes. RNA viruses replicate their genome to make it two stranded which acts like a DNA strand.
4. Chemotherapy prevents cell division of all rapidly multiplying cells. Since active cell multiplication occurs in hair roots and oral mucosa also it causes hair fall and oral ulcers.
Monoclonal antibodies do not affect cell multiplication directly. So, they are not associated with hair loss and oral ulcers. Monoclonal antibodies selectively kill only the cancer cells. They can be associated with opportunistic infections.
5. Progress of disease accelerates over time because the cancer cell mass increases. More the cell mass, greater is the replication.
I hope this answers your query effectively.
In case you have additional questions or doubts, you can forward them to me, and I shall be glad to help you out.
Regards.