CMT Type 1 Found in Woman After Standard Breast Cancer Care, Case Study Reports

Researchers report what may be the first case of Charcot-Marie-Tooth (CMT) type 1 neuropathy being diagnosed in a 55-year-old patient after she was given standard care for advanced breast cancer.

Doctors later found the woman had a family history of CMT, and the scientists speculate that the neuropathy was triggered by the use of chemotherapy.

The case report, “Charcot-Marie-Tooth hereditary neuropathy revealed after administration of docetaxel in advanced breast cancer,” appeared in the journal World Journal of Clinical Oncology.

The most common case of hereditary neuropathy — CMT type Ⅰ neuropathy — represents 70 to 80 percent of all the hereditary neuropathies. Patients are usually diagnosed between the ages of 5 and 25.

, but now authors report what they believe is the first case of CMT type I diagnosed in 55-year-old woman after she received therapy for advanced (metastatic) breast cancer.

The woman was diagnosed with HER2-positive and hormonal receptor-positive stage 4 metastatic breast cancer in 2014, with metastasis, one tumor on the liver. She received standard first-line care — Taxotere (docetaxel), a chemotherapy, combined with two antibodies, Herceptin (trastuzumab) and Perjeta (pertuzumab) — followed by surgery to remove the breast tumor and radiofrequency ablation (heat made by radio waves to kill cancer cells) for the liver metastasis.

Chemotherapy was given in six cycles, after which the patient was kept on maintenance therapy with Herceptin and Perjeta.

“Three months after the last cycle of chemotherapy, the patient developed numbness in the extremities, generalized depressed tendon reflexes, and hypoesthesia [reduced sense of touch or sensation] in the lower third of legs,” the researchers wrote.

In a clinical examination, pes cavus foot deformity, bilateral foot drop, and generalized depressed tendon reflexes were also detected.

A complete evaluation of the patient’s medical history was then performed, and revealed that several members of her family — a sister, niece and her grandfather — had been diagnosed with CMT type IA disease.

“A genetic analysis of PMP22 gene confirmed the diagnosis in our patient and conduction velocity studies demonstrated demyelinating abnormalities concordant with the diagnosis,” the researchers wrote.

Following the CMT diagnosis, the woman continued with targeted breast cancer therapy (Herceptin and Perjeta) and hormonal treatment (letrozole), and is now in complete remission. In light of her persistent neurologic deficits, the doctors recommended physiotherapy (for maintaining posture and balance) and an avoidance of neurotoxic chemotherapies. Additionally, her two sons were assigned to genetic counseling.

Overall, “this case stresses again the necessity to obtain a complete personal and familial anamnesis [patient account of family medical history], and to perform a neurologic examination before the administration of neurotoxic chemotherapeutical agents to prevent the clinical expression of these hereditary neuropathies,” the study’s authors concluded.