Lactose intolerance associated with adjuvant 5-fluorouracil-based chemotherapy for colorectal cancer.

Background & Aims: Bowel mucosal injury associated with 5-fluorouracil (5-FU) treatment might result in secondary lactose intolerance. The frequency and clinical significance of 5-FU-related hypolactasia are unknown.

Methods: One hundred fifty patients randomly assigned to receive 1 of 2 adjuvant 5-FU-based chemotherapy regimens, the Mayo regimen or the simplified de Gramont regimen, were studied for lactose tolerance by using an oral lactose absorption test, a symptom questionnaire, treatment-related toxicity, and Subjective Global Assessment of Nutritional Status questionnaire before, during, and 2 and 6 months after chemotherapy for colorectal cancer.