A prospective analysis of factors that influence weight loss in patients undergoing radiotherapy.

Malnutrition occurs frequently in patients with cancer. Indeed, a variety of nutritional and tumor-related factors must be taken into account in these patients. Recognizing this relationship, we aimed to prospectively evaluate the risk factors that influence weight loss in patients undergoing radiotherapy with oral nutritional supplementation and dietetic counseling. Weight loss of 74 patients during radiotherapy and 1 month after treatment was analyzed. Parameters such as age, gender, tumor location, tumor stage, Eastern Cooperative Oncology Group performance status (ECOG PS) score, and the use of chemotherapy were analyzed to evaluate their influence on weight loss. All patients underwent oral nutritional supplementation and dietetic counseling. Forty-six (65.7%) patients lost weight, with a mean weight loss of (4.73 ± 3.91) kg, during radiotherapy. At 1 month after treatment, 45 (66.2%) patients lost weight, presenting a mean weight loss of (4.96 ± 4.04) kg, corresponding to a (6.84 ± 5.24)% net reduction from their baseline weight. Head and neck cancer patients had a mean weight loss of (3.25 ± 5.30) kg, whereas the remaining patients had a mean weight loss of (0.64 ± 2.39) kg (P = 0.028) during radiotherapy. In the multivariate analysis, the head and neck tumor location (P = 0.005), use of chemotherapy (P = 0.011), and ECOG PS score of 2-3 (P = 0.026) were considered independent risk factors. Nutritional status and parameters, such as tumor location (especially the head and neck), the use of chemotherapy, and the ECOG PS score, should be evaluated before radiotherapy because these factors can influence weight loss during radiotherapy and 1 month after treatment.