Dietary intake and nutritional indicators are transiently compromised during radiotherapy for rectal cancer

Patients with rectal cancer receive curative radiotherapy towards the pelvis for 5 weeks. Little is known about the impact of radiotherapy on dietary intake and nutritional status. The objective was to examine whether curative radiotherapy for rectal cancer promoted altered intake of energy and nutrients, and change in nutritional indicators.

Prospective study.

Department of Oncology in a tertiary care hospital.

A total of 31 consecutive patients receiving radiotherapy for rectal cancer (50 Gray).

A 7-day food intake registration, body weight, upper arm circumference, and analyses of blood samples were performed at the start and the end of radiotherapy, and at follow-up 4-6 weeks and 1 year after the end of radiotherapy.

At the end of 5 weeks of radiotherapy, the mean daily energy intake was reduced by 15% from 8.9 to 7.6 MJ as compared with baseline (P = 0.002), and the intake of several nutrients was reduced (P < 0.01). The percentages of energy derived from fat, protein, and carbohydrates did not change, nor did the nutrient density. A transient body weight reduction of < 1 kg was observed (P = 0.009). Serum concentrations of vitamin A and 25-OH vitamin D did not change during radiotherapy. The daily intake of energy and nutrients, and body weight, had increased towards pretreatment values 4-6 weeks after radiotherapy.

Radiotherapy for rectal cancer caused a transient reduction in energy intake and nutritional indicators. The nutritional quality of the diet was unchanged during radiotherapy.