Question

Name cancer which arises due to chromosomal translocation.
(a) Breast cancer
(b) Chronic myelogenous leukaemia (CML)
(c) Cervical cancer
(d) Colon cancer

Answer 1

Cancer that arises due to chromosomal translocation is a type of blood cancer. The chromosome responsible for this cancer is called the Philadelphia chromosome.

Complete answer:
Chromosome translocation is a chromosome abnormality caused by the rearrangement of parts of nonhomologous chromosomes. It may contribute to chronic myelogenous leukaemia or CML. CML happens because the chromosomal part is translocated between chromosomes 9 and 22. This makes the chromosome 22 shorter. It is a cancer of the blood cells.
It is a form of blood- cell cancer that starts in the bone marrow which is progressive and is uncommon. Chronic myeloid leukaemia is usually affecting elderly people.
So, the correct answer is, ‘Chronic myelogenous leukaemia (CML) ’.

Additional information:
- Chromosomal translocation has been related to many forms of human leukaemia and lymphoma and has been related to epithelial tumours such as prostate cancer. One part of a chromosome breaks off and is connected to another chromosome by chromosomal translocation.
- Two separate genes can fuse as a result of such an event. Sometimes, the newly created gene contributes to the production of tumours. This is the case with the Philadelphia chromosome, which is the first translocation linked to human cancer - chronic myelogenous leukaemia. More than 90 percent of patients with chronic myelogenous leukaemia have the Philadelphia chromosome.
- This well-known example of translocation involves the fusion of a proto- oncogene (Proto Oncogene: A gene which is involved in normal growth of cells) .

Note: A tyrosine kinase inhibitor (TKI) is the standard treatment for chronic phase CML. If the first drug stops working or it never worked very well at all, then the dosage may be increased or another TKI may be tried. The only hope for a successful cure for chronic myelogenous leukaemia is a bone marrow transplant, also called a stem cell transplant. It's generally reserved for patients who have not been improved by other therapies, though, because bone marrow transplants have risks and bring a high incidence of serious complications.