A 21-year-old woman developed the photosensitive facial rash depicted along with polyarticular arthralgias. Laboratory investigation revealed anemia, leukopenia, a positive antinuclear antibody test (1:1024), and the presence of anti-double-stranded DNA antibodies. A skin biopsy shows dense lymphocytic infiltrate at the dermo-epidermal junction and around hair follicles. She smokes one pack of cigarettes per day and drinks socially. Family and past medical histories are non-contributory.
Based solely on this patient's underlying medical illness, her increased lifetime risk of which of these internal malignancies is least likely: