A section of researchers believed that cancer is a disease of accumulated random mutations whereas how the mutations can cause cancer and its mechanism too is a million dollar question.
Theory of somatic mutation
As per somatic mutation theory, diversified opinions persist on behalf of gene mutations that lead to cancer. One is the combination of two mutations to produce cancer and the other is the three or four mutations working in a conjunction to produce excessive growth in the cell which becomes cancerous.
To know how many mutations that form cancer, researchers found that every cancer needs an average of eleven mutations. For instance breast cancer type 1 has eleven mutations whereas breast cancer type 2 has eleven different mutations. So the mutations of different tumours of the same region can be different.
As per the data from The cancer genome atlas (TCGA), most cancers have around fifty to eighty mutations.
Mutations are of two types;
- The mutations which can lead to carcinogenesis are called driver mutations.
- Mutations which did not have any effect were called passenger mutations.
Based on a research report, it was identified that each breast or colon cancer has around 13 driver mutations whereas metastatic pancreatic cancer needs around 49 mutations.
Another study reported that different cancers had different rates of mutations whereas some cancers had no mutations at all. It was a drawback to somatic mutation theory as it suggests mutations always drive cancer.
Cancer cells behave differently even though they are replicas of the original human cell. Metastatic cancer also differs genetically from the original tumour. Even metastasis at different sites also differs by twenty or more genetic alterations.
In conclusion, genetic mutations are everywhere and also nowhere in the human body. Even some cancers have many mutations and others don’t have them at all. Rate of mutations necessary to form a cancer is higher than the known rate of mutation in human cells.
We tend to look at the exact cause of mutations that influence the human body to develop cancer rather than apprehending the gene mutations itself is the real cause. Hence, most scientific communities are suggesting that it is not the better approach in providing cancer care.
