Context:
Cancer is a leading cause of morbidity and mortality, and any advance in our capacity to better take care of it is scientifically, economically and socially important. An emerging “magic bullet” in our fight against cancer is called immunotherapy. It works by awakening and empowering the patient’s own immune system to fight cancer. This has led to many cures where a death and pain was the norm. Unlike previous targeted therapies, which where a better than chemotherapy, it has the huge advantage of working on many tumor types. This is especially true for cancer that harbor a lot of point mutations, most likely because they express antigens that can be recognized by the immune system. However, we have observed that in patients harboring two different cancer, this magic bullet may work on one tumor and not the other. The goal of this master was to identify and study patients that harbored multiple tumors and received immunotherapy, then try and see what it teaches us on this important therapeutical tool, hoping to allow us to better treat our patients.
Methods:
We reviewed literature on current immunotherapy treatment options and indications as well as knowledge on skin cancers. However, no article on our specific subject was published at the time of writing. A second approach was using data mining tools on the oncology department data bank searching for patients who had immunotherapy or cutaneous excision during 2016-2020. We then cross-referenced both populations in order to identify those who both underwent cutaneous excision and immunotherapy. Lastly, we selected those who were under treatment at the time of the excision.
We manually reviewed each patient to select only those who were diagnosed a second distinct tumor while under immunotherapy.
Results:
Primary tumors for which immunotherapy was initiated included cutaneous melanoma, pulmonary cancers, ORL cancers (including 1 melanoma of the nasal cavity), vaginal and ocular melanoma, basal cell carcinoma, prostatic, ovarian and renal cancer. After the selection process, 51 patients were included in our study and we noticed an overrepresentation of melanoma, 32/51 (62.74%). After reviewing each patient’s file manually, 12/51 patients were under treatment at the time of diagnosis of a second distinct tumor and only 2/12 (16.67%) were melanomas. Although the population analyzed was not statistically relevant, 4/5 ORL cancers (80%) developed a second distinct malignancy while under CPI. Out of the 7 pulmonary cancers, 3 (42.86%) developed a cutaneous tumor while under treatment. The histology of the second lesions were mostly basal cell carcinoma (5/12 = 41.67%), followed by melanoma (4/12 = 33.33%) and lastly squamous cell carcinoma (3/12 = 25.00%). The duration of CPIs treatment before excision did not seem to influence the results (mean interval of immunotherapy = 7.86 months / median = 3.62 months). Similarly, the primary malignancy outcomes were variable and a larger population needs to be analyzed.
Conclusion:
To conclude, patients can indeed develop a second tumor while under immunotherapy. However, as stated previously, the low number of cases in patients with melanoma at high risk of developing other skin cancers may suggest a bystander effect of immunotherapy on new skin cancers.