Melanoma and CLL co-occurrence and survival: role of KC history

BMC Cancer

Table 3 Association between history of keratinocyte carcinoma and survival following diagnosis of chronic lymphocytic leukemia

Model factors
Model factors	n (%)	Hazard ratio (95% confidence interval)^a
Age at diagnosis (mean [SD])	63.3 (11.2)	1.07 (1.04–1.09)
Smoking status
Never	286 (51.0)	1.0 (ref.)
Former	246 (43.9)	1.61 (1.03–2.50)
Current	29 (5.2)	3.2 (1.28–8.01)
Historical or concurrent melanoma (based on ICD billing codes)
No	536 (93.9)	1.0 (ref.)
Yes	35 (6.1)	2.11 (1.13–3.95)
Chemotherapy as first course treatment
No	480 (84.1)	1.0 (ref.)
Yes	91 (15.9)	2.96 (1.90–4.61)
History of KC
No	458 (80.2)	1.0 (ref.)
Yes	113 (19.8)	1.53 (0.95–2.45)

^aThe Cox regression model was derived using a backward elimination process on a full model including the following factors: age at diagnosis, sex, smoking status, historical or concurrent melanoma (based on ICD billing codes), first course treatment of radiation, immunotherapy and chemotherapy, insurance status, self-reported history of melanoma, and history of keratinocyte carcinoma (bolded variables were retained in the final model)

ISSN: 1471-2407