For melanoma awareness month this May, learn the truth behind common misconceptions.
Melanoma is the rarest, but also the deadliest form of skin cancer, and is the source of both common misconceptions as well as next-generation cancer research. Unlike other skin cancers which arise from the cells that make up the layers of the skin, melanoma originates in the skin’s pigment producing cells called melanocytes. Many researchers at the Rosalind and Morris Goodman Cancer Institute (GCI) are investigating what causes melanoma to develop and spread, with the ultimate goal of improving treatments for patients.
Melanoma is often associated with tanning and lack of sunscreen use, since melanoma and other skin cancers are driven by damage to cells caused by sunburn. Another melanoma risk factor is biological sex – males are more likely to be diagnosed with melanoma, and more likely to die of melanoma. While outdated misconceptions explained this sex difference in melanoma by conflating gender stereotypes with sunscreen use, researchers at the GCI have uncovered a genetic explanation. A gene on the X chromosome, which females have two copies of, is protective against melanoma. Males have only one X chromosome, so they have less genetic protection against melanoma.
A particularly dangerous myth about melanoma is that it is easy to treat by surgical removal of the affected skin. While early detection of melanoma is important for surgical treatment options, melanomas detected later have often spread to other areas of the body and become very difficult to treat. Melanoma is particularly aggressive in spreading, or metastasizing, to the brain. In a study from the GCI, researchers investigated the immune cells within tumors that had originated in the brain or spread there from other tumor types including melanoma. They found striking differences between the groups, which could inform doctors how to best use immunotherapy drugs – therapies that use a patient’s own immune system to target cancer cells and can be effective in treating melanoma.
In addition to promising immune based therapies for melanoma, melanoma is a success story for next-generation cancer therapies which target a specific cancer-causing mutation. About 50% of melanomas are driven by the same mutation, which can be specifically targeted by drugs that inhibit the mutation harboring cancer cells while sparing healthy cells. Pioneering research at the GCI found that these same drugs can target a different class of melanoma mutations, expanding the number of patients who can benefit from existing therapies. Ongoing work at the GCI aims to continue finding new uses for existing therapies as well as new targets for melanoma treatment.
While important strides have been made in treating melanoma, it remains a dangerous disease that precautions should be taken to prevent. Researchers at the GCI are continuing to build on their findings to better inform doctors how to treat melanoma and improve outcomes for patients. The studies highlighted in this article can be found below.
Alkallas, R., Lajoie, M., Moldoveanu, D. et al. Multi-omic analysis reveals significantly mutated genes and DDX3X as a sex-specific tumor suppressor in cutaneous melanoma. Nat Cancer (2020). https://doi.org/10.1038/s43018-020-0077-8
Karimi, E., Yu, M.W., Maritan, S.M. et al. Single-cell spatial immune landscapes of primary and metastatic brain tumours. Nature (2023). https://doi.org/10.1038/s41586-022-05680-3
Dankner, M., Lajoie, M., Moldoveanu, D. et al. Dual MAPK inhibition is an effective therapeutic strategy for a subset of class II BRAF mutant melanomas. Clinical Cancer Research (2018). https://doi.org/10.1158/1078-0432.CCR-17-3384
- Related: https://www.goodmancancer.ca/en/news-details/melanoma-awareness-month-at-the-gci-myths-facts-and-new-research