Sarcoidosis may appear in cancer patients who respond well to treatment with dendritic cell-based vaccines, according to a case series report from Germany.
At the Friedrich-Alexander-University Erlangen-Nürnberg and the associated Erlangen University Hospital, researchers noted three patients with malignant melanoma who developed sarcoidosis after or during such treatment.
The study, “Sarcoidosis Under Dendritic Cell Vaccination Immunotherapy in Long-term Responding Patients with Metastatic Melanoma,” showed that all three patients had no symptoms of their lung or lung lymph node sarcoidosis, needing no treatment for their condition. The study appeared in the journal Anticancer Research.
Dendritic cell vaccination is a cancer immunotherapy that relies on a patient’s own immune cells. Dendritic cells are players of the immune system that take bits and pieces of a tumor and display them on their surface to alert other immune cells. These tumor fragments essentially educate the immune system, telling it what its target look like.
Researchers discovered the patients when going through medical records of 249 patients treated with dendritic cell vaccines since 1997. The three patients received the treatment as part of two clinical trials (NCT00074230 and NCT00053391).
The first patient was a 65-year-old woman whose cancer progressed after standard treatment. Her cancer had spread to the lungs, lung lymph nodes, and adrenal glands. She received 25 vaccinations over a period of 10 years — a treatment that kept her cancer in check. Although some lesions remained, the cancer stopped progressing and spreading.
When vaccination treatment was ended, physicians continued monitoring her condition with regular scans. It was during one such visit, two years after she stopped the vaccination, that doctors detected a new lump in the lung. The chest scan also showed enlarged lung lymph nodes.
They believed, at first, that the cancer had recurred, but a tissue analysis instead indicated that she had developed sarcoidosis. Since she had no symptoms, and her lungs retained their normal capacity, she did not receive treatment.
The second case was a 69-year-old man. Just as the first patient, his cancer had progressed during standard therapy, and he was enrolled in a clinical trial of dendritic cell vaccine treatment. Five years of treatment brought him into complete remission, but the treatment continued.
Three years later physicians noted enlarged lymph nodes on a chest scan. Also this time, they thought the cancer had spread, but found that the patient had developed sarcoidosis. He did not have symptoms and had a normal lung function. While his treatment is still ongoing, he has been free of tumors for four years without the need for sarcoidosis treatment.
The third patient’s story is similar. She was a 64-year-old woman in which cancer had spread to a lymph node before she received the vaccine. She was successfully treated for five years, and then continued being monitored. About four years later, doctors spotted a mass in the right lung on a chest scan.
When they removed what they thought was a tumor, they learned that it was, in fact, sarcoidosis. Like the others, she had no symptoms of the disease, and had a normal lung function. She remained free of tumors, and without the need for sarcoidosis treatment after four years.
Since dendritic cell vaccinations trigger the immune response, it might not be surprising that sarcoidosis — a result of an overactive immune system — follows. Nevertheless, researchers have not explained, so far, the mechanisms behind sarcoidosis linked to cancer immunotherapy.
The research team did, however, note that sarcoidosis can be seen in patients who have a good response to this cancer treatment.