Renal Function Deterioration in Postoperative (Adjuvant) Chemotherapy for Colon Cancer-Real-Life Data

The knowledge concerning mild-to-moderate renal toxicity of adjuvant chemotherapy (CTH) in colon cancer patients is scarce. We retrospectively evaluated changes in the estimated glomerular filtration rate (eGFR) after three months of adjuvant treatment and the overall renal risk of the 6-month regimen in 145 patients who completed three months of therapy at three oncological centers. A decrease in eGFR of at least 1.5 mL/min/1.73 m² after three months and 3.0 mL/min/1.73 m² after six months was considered relevant in terms of kidney-related cardiovascular risk. Out of 114 patients who completed a 6-month regimen, kidney function deterioration occurred in 62 (54.4%) after 3 months and in 54 (47.4%) after 6 months. Age ≥ 70 years (RR = 2.66; 95% CI: 1.15-6.16) and diabetes (RR = 2.52; 95% CI: 0.98-6.45) were risk factors for kidney outcomes during the first three months of CTH. However, renal function decline during the first three months did not increase the risk of further deterioration on CTH continuation. In conclusion, older age and diabetes are factors increasing the risk of renal function deterioration during adjuvant CTH in colon cancer patients without preexisting chronic kidney disease. However, the decline during the first three months does not allow for predicting further changes under continued adjuvant therapy.