Background: Capecitabine is an oral precursor of 5-FU (5' deoxy-5-fluoridine), a commonly prescribed chemotherapeutic agent to treat gastrointestinal and breast cancers. Capecitabine is currently contraindicated in patients with severe renal failure with Glomerular filtration rate <
30 ml/min. Literature review shows limited evidence in safety and effectiveness of using capecitabine in patients undergoing hemodialysis.
Case Report 1 : A 75-year-old old male with a history of end stage renal disease on hemodialysis, was diagnosed with a 10 cm duodenal mass on CT scan when presented with three months history of abdominal pain and 45 lb weight loss. esophagogastroduodenoscopy and biopsy confirmed
adenocarcinoma of duodenum/ampulla. Patient was deemed to be a high-risk candidate for Whipple’s procedure. The case was discussed in multidisciplinary tumor board and the patient was offered concurrent chemotherapy and radiation with capecitabine 500 mg BID. Posttreatment
CT scans suggested 60% shrinkage in tumor size. Patient was continued on capecitabine 300 mg BID two weeks on and one week off with continued response noted on restaging CT scans.
Case Report 2 : A 76-year-old male with end stage renal disease on hemodialysis complained of bleeding per rectum for over 2 years. A colonoscopy showed a circumferential mass at 15 cm from anal verge, and biopsy was consistent with rectal adeno carcinoma. PET/CT scan confirmed primary lesion in rectum as well as abnormal retroperitoneal and left iliac adenopathy with high FDG uptake. EUS staged disease at uT3N0Mx. Given significant pain and bleeding patient was offered palliative radiation along with low dose capecitabine 500 mg BID. Two months after concurrent chemotherapy and radiation, restaging scans showed 50% shrinkage in primary tumor. The patient opted to continue treatment with capecitabine and completed two more cycles of 300 mg BID two weeks on and one week off. A repeat CT scan showed near complete resolution of rectal mass and lymphadenopathy.
Conclusions: Capecitabine is converted to active form 5-FU in liver by thymidine phosphorylase. Over 95% of the drug is excreted in urine. In the original phase II trial utilizing capecitabine at 1250 mg/m2 BID, four patients with GFR < 30 ml/min noted to have grade 3-4 toxicities. Jhaveri et al. in their retrospective analysis showed 12 patients tolerated reduced doses.
