Fingerprint-erasing cancer drug may delay people entering U.S.

Patients taking a commonly prescribed cancer drug may draw extra scrutiny from U.S. immigration authorities because a side effect can make their fingerprints invisible to scanners, Singapore oncologists said.

Customs officials held a 62-year-old Indonesian man for four hours last December after side effects from Roche Holding AG's Xeloda erased his fingerprints, the doctors wrote in a case study published in the Annals of Oncology. Cancer patients should travel with a doctor's letter to avoid being detained, the authors said.

"We are not certain about the duration of use before loss of fingerprints sets in," said the man's doctor, Eng-Huat Tan, a senior consultant in the medical oncology department at Singapore's National Cancer Center, in an e-mail. Roche should consider warning patients that they might lose their fingerprints, Tan said.

More than half of patients taking Xeloda, known generically as capecitabine, experience some numbness, swelling or blistering on their hands and feet, according to the drug's label. Known as hand-foot syndrome, the side effects can wear down the ridges on fingertips, Tan said.

Patients with hand-foot syndrome are usually taken off Xeloda until the symptoms diminish, said Alexander Klauser, a spokesman for Basel, Switzerland-based Roche. The condition "generally occurs with increased cumulative doses and longer treatment," Klauser said.

The patient held at customs in December had been taking Xeloda for more than three years to treat head and neck cancer. The redness and swelling on his hands and feet wasn't severe enough to affect his day-to-day activities, according to the case study.

The man told officials he didn't know his fingerprints had vanished.