Ylva Naeser: The role of imaging in follow-up and prognosis of patients radically operated for melanoma

Abstract

Cutaneous malignant melanoma (CMM) is the cancer type in Sweden with the most rapidly increasing incidence. This thesis investigated if whole-body imaging improves the follow-up scheme post-surgery in high-risk CMM patients and explored the long-term outcomes for early-stage melanoma patients compared to the general population.

We launched the nationwide randomized phase III study: “Trial to assess the Role of Imaging after radical surgery of CMM stage IIB-C and III (TRIM study, NCT 03116412)” with allocation to physical examinations for three years according to Swedish national guidelines +/- five scheduled whole-body imaging procedures. Primary endpoint is overall survival (OS) at five years. Secondary endpoints include Health-Related Quality of Life (HRQoL) outcomes.

In paper I, the TRIM study protocol and the recruitment status were described and evaluated. Based on enrollment of more than 550 patients at 19 centra, we found the study protocol feasible and identified some obstacles for optimal inclusion rate.

In paper II, we evaluated HRQoL and anxiety/depression in > 200 patients in the TRIM study who responded to the Hospital Anxiety and Depression (HAD) scale and the EORTC Quality of Life Questionnaire (QLQ)-C30 at baseline and after one year. No statistically significant differences were found between the study arms. Levels of anxiety and depression symptoms were generally low.

The Malignant Melanoma Database Sweden (MMBaSe) was created by record linkages between the Swedish Melanoma Register and several population-based registers. The MMBaSe includes 67 000 individuals diagnosed with CMM or melanoma in situ (MIS) between 1996 and 2018 and matched, randomly selected, melanoma-free comparators representing the general population.

Overall survival and mortality risks were assessed in two cohort studies in patients with MIS (paper III) and thin CMM (≤ 1 mm) (paper IV) in comparison to their matched comparators. Mortality risks were adjusted for socioeconomic status (SES) and comorbidities. We found several statistically significant differences. Individuals diagnosed with melanoma had higher SES and a lower comorbidity burden. While melanoma patients were at higher risk of dying from CMM, they had lower risks of dying from several other diseases.

In paper III we found a better OS and a lower risk of death in MIS patients, findings that remained after adjustments.

In paper IV, patients with thin CMM had a similar OS as the general population. In individuals with stage T1a disease (< 0.8 mm), the OS at 5 years was slightly better than in comparators.