Patients with chronic lymphocytic leukemia (CLL) should be routinely monitored for melanoma, according to researchers.
A study of 470 CLL patients showed they have a significantly higher risk of invasive melanoma than the general population.
Most of the melanomas reported in this study were detected via routine surveillance, and most were discovered before they reached an advanced stage.
Clive Zent, MD, of Wilmot Cancer Institute at the University of Rochester Medical Center in Rochester, New York, and his colleagues described this study in Leukemia Research.
The researchers analyzed data on 470 CLL patients followed for 2849 person-years. Eighteen of these patients developed 22 melanomas. This included 14 cases of invasive melanoma in 13 patients.
The rate of invasive melanoma was significantly higher in this CLL cohort than the rate observed in the age- and sex-matched general population. The standardized incidence ratio was 6.32.
“We do not for sure know why CLL patients are more susceptible to melanoma, but the most likely cause is a suppressed immune system,” Dr Zent noted.
“Normally, in people with healthy immune systems, malignant skin cells might be detected and destroyed before they become a problem. But in CLL patients, failure of this control system increases the rate at which cancer cells can grow into tumors and also the likelihood that they will become invasive or spread to distant sites.”
Detection and management
Fifteen of the 22 melanomas (68.2%) in the CLL cohort were detected via surveillance in a dermatology clinic, and 2 (9.1%) were detected at the CLL/lymphoma clinic.
Three cases of melanoma (14.3%) were detected within the first year of a patient’s CLL diagnosis.
Seven melanomas (33.3%) were detected at pathologic stage 0, 8 (38.1%) at stage I, 2 (9.5%) at stage II, 3 (14.3%) at stage III, and 1 (4.8%) at stage IV. Detailed data were not available for the remaining case.
Melanomas were managed with wide local excision (n=19), sentinel node biopsies (n=6), Mohs surgery (n=1), drugs (n=2), palliative care (n=1), and comfort care (n=1).
The 4 patients who received drugs, palliative care, or comfort care had advanced melanoma.
The patient who received palliative care was still alive at 2.4 years of follow-up. The patient who received comfort care died of metastatic melanoma 1.4 years after diagnosis.
The third patient with advanced melanoma received 2 cycles of dacarbazine and palliative radiation to lung and brain metastases. This patient died 3.6 years after melanoma diagnosis.
The fourth patient received ipilimumab for the melanoma while also receiving ibrutinib to treat her CLL. When the ipilimumab failed, the patient proceeded to pembrolizumab and achieved a near-complete response within 3 months. Then, an intensely hypermetabolic abdominal node was detected and successfully treated with radiation.
The patient continued on pembrolizumab, and her melanoma was in sustained remission at last follow-up, after 23 cycles of pembrolizumab. Her CLL was still responding to ibrutinib at that point as well.
Based on these data, Dr Zent and his colleagues recommend routine melanoma screening for CLL patients. The team believes such surveillance might decrease morbidity and mortality in these patients, although more research is needed to confirm this theory.