The role and impact of immunotherapy in multiple malignancies in the Mexican population.

Abstract

e14570 Background: Cancer in Mexico represents the third cause of death nationally. Immunotherapy agents have changed management and prognosis of cancer patients. Immune-checkpoint agents are now being used as both first- and second-line treatment improving cancer patient prognosis, nevertheless it is not always accessible. Methods: Retrospective review of patients diagnosed with any type of cancer that received immunotherapy during their disease course from the last 5-years. We present the most common malignancies, immunotherapeutic regimens received, population characteristics and survival analysis. Results: 130 records of patients ≥18 years that received immunotherapy were included. 52.3% female with mean age of 59 years (range, 22-89 years), 48.5% former smokers (average pack/year of 22.5) and 31.5% asbestos exposure. 53.1% were ECOG 0 and 82.3% clinical stage IV. 62.3% of cases were lung adenocarcinoma, followed by lung epidermoid carcinoma (13.1%) and 10% small-cell lung carcinoma. Immunotherapeutic agents used included nivolumab in 63.1%, pembrolizumab 12.3%, nivolumab + ipilimumab 8.5%, durvalumab 6.2%, pembrolizumab + ipilimumab 4.6%. 36.2% of patients received immunotherapy as second line treatment, 30.0% as third and 23.8% as first line treatment. The best Response Evaluation Criteria in Solid Tumors (RECIST) was RECIST 3 in 46.2% followed by RECIST 0 with 25.4%. Median progression-free survival (PFS) was 5 months (95% CI; 3.883-6.117) and median OS of 13 months (95% CI; 10.210-15.790). Analysis per immunotherapy on PFS (p = 0.0414) and OS (p = 0.0046) demonstrated pembrolizumab had the longest median PFS with 19-months and OS with 22-months. Analysis between tumor types was significant for both PFS (p = 0.0018) and OS (p = 0.0090) with melanoma having the longest median PFS (42-months) and OS (46-months). Conclusions: Immunotherapy has changed cancer management; however, its use depends on specific biomarkers and adequate patient selection. Not all patients benefit from immunotherapy, in a country like ours where resources are limited, it is of vital importance to properly select candidates for immunotherapy. Even though, all patients had an FDA-approved indication at the time of receiving immunotherapy, PFS and OS are not as significant as Phase 3 studies demonstrate, this may be due to late stages, advanced ECOG, correct biomarkers availability and adequate patient selection. It is important to mention that about 40-60% of patients with immunotherapy do not respond adequately. In our study, because there is more evidence with pembrolizumab, the patients who received it were better chosen and therefore there was an impact in PFS and OS. Immunotherapy selection also depends on physician experience to the different immunotherapy regimens.