MIAMI BEACH – Patients who have undergone solid organ transplantation are at greater risk for subsequent tumor development, and head and neck cancers can be particularly aggressive, according to results of a single-institution study.
Dr. Robert H. Deeb and his associates at Henry Ford Hospital in Detroit studied 3,639 patients who underwent solid organ transplantation between January 1990 and December 2011. By retrospectively searching electronic medical records, they identified 95 people who developed cutaneous, salivary gland, or mucosal malignancies.
They found a 2.1% incidence of cutaneous cancers and a 0.5% incidence of noncutaneous head and neck cancers in this population. Despite a relatively low overall 2.6% incidence, there are reasons for concern, Dr. Deeb said at the Triological Society’s Combined Sections Meeting, which was jointly sponsored by the Triological Society and the American College of Surgeons. When cutaneous cancers did occur, they were more aggressive and were associated with shorter 1-year survival rates.
Henry Ford Transplant Institute maintains a noncutaneous tumor registry. This allowed the researchers to compare survival and other factors. Compared with the "nontransplant tumor registry in our institution, we found significantly fewer patients were alive at 1 year," Dr. Deeb said. Specifically, 55% of posttransplant patients with these cancers survived to 1 year, compared with 81% of nontransplant patients. There were no significant differences between groups in terms of age, sex, stage at diagnosis, or 5-year survival.
More than half (52%) of the patients who developed skin cancers had multiple head and neck cutaneous malignancies, pointing to the aggressive nature of these cancers, said Dr. Deeb of the department of otolaryngology–head and neck surgery at Henry Ford Hospital.
"We believe these patients require aggressive screening, treatment, and follow-up," Dr. Deeb said.
Of the 78 cutaneous head and neck cancers, 51% were squamous cell carcinomas, 36% were basal cell carcinomas, and the remaining 13% were other skin cancer types. The cheek and scalp were the most common sites. The patients’ average age was 61 years at the time of diagnosis, and 74% were men. Skin cancer developed a mean 4 years after transplant surgery.
Four patients had a salivary gland cancer and 13 had an upper aerodigestive tract mucosal malignancy. The average patient age in this group was 60 years, and 94% were men. Cancer was diagnosed a mean 66 months post transplantation. All 13 of the mucosal malignancies in the study were squamous cell carcinomas, Dr. Deeb said.
Kidney, liver, and heart were the most commonly transplanted organs among patients who ultimately developed these head and neck malignancies.
Although immunosuppressants are universally prescribed to prevent organ rejection following transplant surgery, the exact mechanism for subsequent cancer development remains unknown, Dr. Deeb said. Loss of immunosurveillance is one possibility; uncontrolled cell proliferation from chronic and low-level antigenic stimulation throughout the body is another. In addition, he said, immunosuppressants might somehow activate oncogenic viruses.
Despite the findings of this study, Dr. Deeb said that the benefits of solid organ transplantation still generally outweigh the risk of subsequent cancer development.
Henry Ford Hospital funded the study. Dr. Deeb said that he had no relevant disclosures.