Normal tissue continually evolves and changes, with specific tissue types exhibiting more mutations than others. The risk of cancer varies significantly between different tissues of the body, with some cell types, such as the colon and breast, being more prone to cancer and others, such as brain, bone, and muscle, developing tumors only rarely.
Each cycle of DNA replication is linked with a continuous error frequency, resulting in the uncontrolled accumulation of somatic mutations and increasing the probability of tumor development. The cumulative number of past stem-cell divisions within each tissue is connected with lifelong cancer risk.
Therefore, the total number of divisions of the normal self-renewing cells that sustain the tissue’s homeostasis is substantially connected with the lifetime risk of malignancies of many distinct tissue types. According to the previous findings, just one-third of the variance in cancer risk between tissues may be attributed to environmental or genetic variables.
Many scholars stated that most cancer cases result from poor luck or spontaneous mutations that occur during DNA replication in normal, noncancerous stem cells. Nonetheless, not all tissues are responsive to the same external influences; they do not react in the same manner.
The difference between tissues might explain why certain cancers are more heavily dependent on risk factors outside of the body than others. What was referred to as ‘poor luck’ would thus be the way of life and external circumstances that might impact a tumor’s complex system and surroundings. Cancer risk might thus be reduced by promoting a healthy lifestyle.
The researchers discovered the most alterations in the lung, esophagus, and sun-exposed epidermis tissues. These tissues are frequently exposed to environmental elements such as tobacco smoking, hot and cold drinks, and UV light, which can cause mutations. Consequently, cancer rates are lower in muscle, heart, and adipose tissue (liposarcomas) than elsewhere.