Chemotherapy and numb feet: what to know about neuropathy

If you are being treated for cancer, or have finished treatment, and your feet have become numb, tingly or painful, you are not imagining it and you are not alone. Nerve damage from chemotherapy is a known effect of several drugs. Here is what the guidelines say about it, and how a foot-focused evaluation can help alongside your cancer care.

What chemotherapy-induced neuropathy is

Peripheral neuropathy means damage to the nerves outside the brain and spinal cord. Chemotherapies such as cisplatin, paclitaxel and vincristine are among the drugs named as causes of toxic neuropathy.^[1] Like most neuropathies, it is typically length-dependent: symptoms appear in the longest nerves, which reach the toes, and progress upward over time, on both sides.^[1] In people given cisplatin, for example, testing typically shows a primarily sensory nerve problem.^[3]

What the guideline says

The ASCO guideline on chemotherapy-induced peripheral neuropathy was updated in 2020, based on systematic reviews and clinical trials. Its main points:^[2]

• Prevention. No agents are recommended for preventing the condition, and acetyl-l-carnitine should be discouraged.
• Dose changes. Clinicians should assess whether delaying, reducing, substituting or stopping chemotherapy is appropriate in patients who develop intolerable neuropathy or functional impairment. That decision belongs to you and your oncology team.
• Treatment of painful neuropathy. Duloxetine is the only agent with appropriate evidence to support its use in established painful neuropathy, and the amount of benefit is limited.

That last point is worth sitting with: the guideline found appropriate evidence for only one medicine, and even its benefit is limited. It is reasonable to ask your oncology or pain team what they recommend for you.

What you can do

• Report symptoms early, before your next cycle, rather than toughing it out. Your team can only weigh dose changes if they know.
• Protect numb feet. Numb skin is easy to injure without noticing. Look at your feet every day, wear well-fitting shoes and socks indoors and out, and get any new blister or wound checked promptly.
• Mention balance problems or falls to your team, so they know how the symptoms are affecting you.
• Keep a short diary of where the symptoms are and what makes them better or worse. Our guide to how to describe nerve pain shows what to note.

Is it always the chemotherapy?

Not always. Many things can cause numb or painful feet, including diabetes, low vitamin B12, alcohol and pinched nerves, and more than one can be present.^[1] Neuropathy can also coexist with a compressive problem such as a nerve trapped at the ankle, and the two can mask each other.^[4] A pinched nerve in the foot causes symptoms in one nerve’s area, often in one foot, and is treated differently. See peripheral neuropathy and numbness in only one foot.

How we fit in

A foot-focused evaluation complements your oncology, primary care and neurology care. It typically includes a history, an examination of sensation, strength, circulation, skin, foot shape and footwear, and an assessment of your risk of injury, with a plan for protective care. Blood tests and nerve studies, when needed, are arranged with your other clinicians. We don’t change your cancer treatment; decisions about chemotherapy stay with your oncology team.

When to see a specialist

Consider an evaluation if numbness, tingling or pain in your feet is getting worse, limits your walking or balance, or is concentrated in one spot or one foot.