Along with incidence, mortality, and prevalence, survival is a key indicator for the epidemiological surveillance and monitoring of cancers; it is essential for evaluating the healthcare system as a whole and measuring the impact of public policies on prevention, screening, and care. This is the first survival study conducted using registry data for Martinique and Réunion. These results, presented in separate publications for each department, provide estimates of 1- and 5-year survival following a cancer diagnosis for ten cancer sites and compare these estimates with those from mainland France published between September 2020 and July 2021. The key elements of the methodology used are detailed in a separate document. The decision was made to discuss the results for each cancer site and then provide comparisons with mainland France to better understand the specific characteristics observed in these territories. As in the French Antilles and French Guiana, the overall incidence of cancer in Réunion is lower than that reported in mainland France. However, certain cancer sites are overrepresented compared to what is observed in mainland France. Indeed, the age-standardized incidence rates for stomach cancer in men and women, esophageal cancer in men, and cervical cancer in women are significantly higher than those in mainland France. For the 10 cancer sites studied, the age-standardized net survival (SNS) for cancers in Réunion is generally lower than that observed in mainland France, but the observed differences vary significantly depending on the tumor site. Thus, the differences in 5-year SSS are greatest for cancers of the lip, mouth, and pharynx (37% in Réunion vs. 45% in mainland France), the colon and rectum (57% vs. 63%), breast (81% vs. 88%), prostate (85% vs. 93%), multiple myeloma/plasmacytoma (52% vs. 60%), and uterine body cancer (67% vs. 74%). These differences are less pronounced for cancers of the esophagus (13% vs. 17%), stomach (25% vs. 30%), and lung (17% vs. 20%). Finally, survival rates are similar for cervical cancer (62% vs. 63%). These differences are often attributable, at least in part, to higher excess mortality rates in Réunion than in mainland France at the time of diagnosis and in the first few months following diagnosis, particularly among the oldest patients. Many factors may explain these results, such as diagnoses made at more advanced stages, difficulties in managing certain cancers related to age and/or comorbidities, tumors with more unfavorable histopathological characteristics, etc. Site-specific studies are needed to explore the various determinants of survival among people with cancer in Réunion, particularly with regard to patients’ socioeconomic characteristics, as numerous studies have already demonstrated a link between socioeconomic status and survival among people with cancer.