[Validation of the Swedish melanoma registry shows limited misreporting. Incomplete for 4 percent of patients in sentinel node diagnostics]. / Validering av svenska melanom-registret visar liten felregistrering - Inkomplett för 4 procent av patienterna vid sentinel node-diagnostik.

Registers of quality can be used to ensure that health care recommendations are followed, to verify the logistics of care and serve as a basis for research when population based data are needed. Validation of quality is important and is the fundament of accurate interpretation of collected data. In the present validation of sentinel node biopsy (SN) for malignant melanoma in Southern Sweden during  2013, we see that registration is incomplete in 4% of the cases. In some of the cases it appears that treating physicians may be unaware of treatment recommendations regarding SN in melanoma.

Molecular stratification of metastatic melanoma using gene expression profiling: Prediction of survival outcome and benefit from molecular targeted therapy.

Melanoma is currently divided on a genetic level according to mutational status. However, this classification does not optimally predict prognosis. In prior studies, we have defined gene expression phenotypes (high-immune, pigmentation, proliferative and normal-like), which are predictive of survival outcome as well as informative of biology. Herein, we employed a population-based metastatic melanoma cohort and external cohorts to determine the prognostic and predictive significance of the gene expression phenotypes. We performed expression profiling on 214 cutaneous melanoma tumors and found an increased risk of developing distant metastases in the pigmentation (HR, 1.9; 95% CI, 1.05-3.28; P=0.03) and proliferative (HR, 2.8; 95% CI, 1.43-5.57; P=0.003) groups as compared to the high-immune response group. Further genetic characterization of melanomas using targeted deep-sequencing revealed similar mutational patterns across these phenotypes. We also used publicly available expression profiling data from melanoma patients treated with targeted or vaccine therapy in order to determine if our signatures predicted therapeutic response. In patients receiving targeted therapy, melanomas resistant to targeted therapy were enriched in the MITF-low proliferative subtype as compared to pre-treatment biopsies (P=0.02). In summary, the melanoma gene expression phenotypes are highly predictive of survival outcome and can further help to discriminate patients responding to targeted therapy.