Capecitabine or 5-FU With Pegylated Interferon Alpha-2b in Unresectable/Metastatic Cutaneous Squamous Cell Carcinoma

Drug administration will occur on an outpatient basis at the infusion center at Moffitt Cancer Center. Dose will be weight-based. Starting treatment doses of 3 mcg/kg will be given subcutaneously (SC) injection in the thigh, abdominal wall, or upper arm every week for a total of 27 weeks as tolerated.

Drug administration will be on an outpatient basis. Capecitabine will be administered at an initial dose of 800 mg/m\^2 by mouth twice daily on days 1-14 of a 21 day cycle with days 15-21 off. This cycle will be repeated every 21 days during the study for a maximum of 9 cycles as tolerated. Administration via feeding tube in patients unable to swallow is permitted.

If participants are not able to acquire oral capecitabine, then treating physicians will start participants on infusional 5-FU which can be delivered via standard of care. Participants will need to have a port placed for continuous infusion treatments. 5-FU pumps will be activated in the infusion center at Moffitt Cancer Center with a starting dose of 800 mg/m\^2 days 1-4, with pump removal on day 5 at the infusion center. 5-FU pumps will be attached every 21 days (1 cycle) for a maximum of 9 cycles.