Association between nutritional status, chemotherapy cycle count and treatment responses in adults with cancer in Ethiopia: a prospective cohort study

Background Malnutrition is common in patients with cancer. Limited data exist on the association between nutritional status, chemotherapy cycles and therapeutic responses in low-resource settings. This study investigated the association between pretreatment nutritional status, chemotherapy cycles and treatment response in Addis Ababa, Ethiopia, providing insights through count data analysis. Methods A multicentre prospective cohort study was conducted from February 2024 to June 2025, involving 400 patients with solid tumours followed from prior to chemotherapy to 1 month after completing treatment. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment, and treatment response was measured using the Response Evaluation Criteria in Solid Tumours (V.1.1). Multivariable logistic and Poisson regression analyses were used to determine the association between malnutrition, treatment response and number of chemotherapy cycles. Results At baseline, 39% of the patients exhibited severe malnutrition. Of the 400 recruited participants, only 204 (51%) completed six or more chemotherapy cycles, and 19.6% showed progressive disease (PD). In bivariate analysis, severe malnutrition was associated with PD (crude OR = 2.67 (95% CI: 1.12 to 6.1)). In the multivariable logistic regression analysis, low dietary diversity (adjusted OR (AOR) = 3.63 (95% CI: 1.19 to 11.05)) and low performance status (AOR = 4.3 (95% CI 1.35 to 13.67)) were associated with PD. Additionally, based on Poisson regression, patients with severe malnutrition received 17% fewer chemotherapy cycles than well-nourished patients (incidence rate ratio = 0.83 (95% CI: 0.73 to 0.93)). Conclusions Based on a prospective cohort study, malnutrition may not predict chemotherapy response. However, it was associated with a reduced number of chemotherapy cycles. Therefore, early nutritional assessment and intervention are imperative to reduce treatment dropouts. Patients should also be encouraged to consume a diverse diet rich in essential nutrients to improve their treatment responses.