Kidney Dysfunction

Kidneys play a crucial role in regulating water, electrolytes, acid-base balance, and blood pressure. There is a close relationship between cancer and kidney function as cancer patients may experience various kidney issues. In addition, kidney dysfunction can affect cancer treatment.

Cancer patients can experience acute renal failure for various reasons:

• Tumors or metastatic lymph nodes blocking the urinary tract
• Treatments such as:
  • platinum-based chemotherapy,
  • targeted therapy
  • immunotherapy
• Pain management with non-steroidal anti-inflammatory drugs (NSAIDs)
• The use of contrast agents

Older cancer patients often have other medical conditions, like diabetes or hypertension, which can cause chronic kidney disease and affect chemotherapy choices and dosages. Even cancer patients with chronic kidney disease can continue chemotherapy, but dose adjustments are necessary for safe treatment.

Kidney function is usually assessed through blood and urine tests. Acute kidney injury refers to a sudden increase in creatinine levels in the blood or a sharp decrease in urine output. Chronic kidney disease(CKD) is defined as a decline in kidney function lasting more than three months. The normal estimated glomerular filtration rate (eGFR) is about 100–120 ml/min/1.73 m², which gradually decreases by 0.8–1.0 ml/min/1.73 m² each year after the age of 30-40.

CKD is classified into 5 stages based on eGFR:

• Stage 1: eGFR > 90 ml/min/1.73 m² (with mild kidney disease, such as proteinuria)
• Stage 2: eGFR 60-89 ml/min/1.73 m²
• Stage 3: eGFR 30-59 ml/min/1.73 m²
• Stage 4: eGFR 15-29 ml/min/1.73 m²
• Stage 5: eGFR < 15 ml/min/1.73 m² (end-stage renal failure), requiring dialysis or kidney transplant.

Maintaining good kidney function begins from your living style. Have a healthy diet with low salt and low sugar. Drink plenty of water. If you need to take painkillers, avoid taking NSAIDs over the counter and consult your doctors before taking any medications.

Special thanks to Dr. Yap Yat Hin Desmond, Department of Medicine, the University of Hong Kong, for authoring this article.