8 predictors of advanced-stage Merkel cell carcinoma at initial diagnosis
There are several factors associated with advanced-stage Merkel cell carcinoma (MCC) at initial diagnosis and the use of radiation therapy (RT), a recent study has found.
Of the 11,917 patients identified, 3,152 and 4,586 patients were excluded from the staging and RT analyses, respectively, due to lack of available data.
The following factors predicted advanced-stage MCC at the time of initial diagnosis: African American ethnicity (odds ratio [OR], 1.49; 95 percent CI, 1.06–2.10; p=0.023), lack of medical insurance (OR, 2.15; 1.40–3.30; p<0.001), Charlson-Deyo comorbidity score of ≥1 (OR, 1.21; 1.08–1.34; p<0.001), residence of >26 miles from a treatment facility (OR, 1.18; 1.03–1.35; p=0.015), tumour located on the lower limb/hip (OR, 1.59; 1.42–1.78; p<0.001) or trunk (OR, 2.05; 1.81–2.33; p<0.001), and poorly (OR, 2.57; 1.13–5.82; p=0.024) or undifferentiated (OR, 3.11; 1.36–7.15; p=0.007) tumour histology.
Native American ethnicity (OR, 5.04; 1.10–22.99; p=0.037), tumour size of 1.5–2.7 cm (OR, 1.27; 1.10–1.47; p=0.001), electing not to have surgery (OR, 2.77; 1.90–4.03; p<0.001), positive postsurgical margins (OR, 1.39; 1.18–1.63; p<0.001), and receiving treatment at a comprehensive cancer programme (OR, 1.25; 1.03–1.50; p=0.020) were associated with the use of RT.
“Healthcare models should account for these factors, and efforts should be directed toward improving those that are modifiable,” the investigators said.
This study was a cross-sectional, retrospective analysis of patients with MCC registered in the National Cancer Database during the period from 2004 to 2013. Its research design limited the generalizability of the results, while the precise details of RT regimens used were not available.
“The stage of disease at initial diagnosis and the use of RT are important determinants of survival in patients with MCC,” the investigators said.