Study addresses knowledge gap of clinical features and outcomes of Black patients with melanoma

By Pooja Toshniwal PahariaReviewed by Danielle Ellis, B.Sc.Jan 25 2024

In a recent study published in JAMA Dermatology, researchers identified patient- and tumor-level melanoma features in black individuals.

Background

Melanoma is a frequent disease among black individuals, with annual incidences of one in 100,000 and worse survival rates compared to white patients. Population studies provide most melanoma-related data, which lack particular information regarding anatomic areas, immune status, prior cancer history, variant sequences, disease course, and therapies. Further research is required to improve the understanding of the risk factors and outcomes for black patients with immunodeficiencies.

About the study

In the present study, researchers investigated variables associated with melanoma development and poor outcomes in black individuals.

The study included self-reported black individuals with histopathologically confirmed melanoma from two tertiary care hospitals [the University of Texas Southwestern (UTSW) Medical Center and Parkland Health] in Dallas from January 2006 to October 2022. The team identified study participants using (i) melanoma patient registries at UTSW reporting to the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute (NCI) and (ii) keyword-based searches of histopathology reports in electronic medical records.

Patient-level characteristics investigated included demographics such as age and sex, personal and parental medical histories, comorbidities, immune status, clinical characteristics, and medications. Tumor-level characteristics included the primary tumor site, histological subtype of melanoma, clinical and pathological stages, molecular and genetic tests, imaging reports, imaging results, histopathology reports, metastasis, melanoma treatments, survival rates, and death cause.

The team defined immunosuppression based on stem cell transplantation (SCT) within five years of tumor diagnosis, human immunodeficiency virus (HIV) infections with a cluster of differentiation 4-expressing helper T (CD4+) lymphocyte counts below 200 cells/mm³, cytotoxic chemotherapy treatment within one year, corticosteroids for ≥12 months, or prior long-term usage of immunosuppressive medications. Acral sites included hands and feet, including nails. The non-acral sites included other non-mucosal, cutaneous sites.

The team performed descriptive analyses to compare study covariates and outcome measures by anatomical primary groups and supplemental analyses by analyzing each covariate by the histologic subtype.

Results

The study included 48 black individuals with melanoma, among whom the median age at tumor diagnosis was 62 years, and 30 (63%) were female. Among 48 patients, 60% (n=29) had stages 0 to II (local) disease, 23% (n=11) had stage III (regional) disease, and 8.0% (n=4) had stage IV (distant) disease. Ultimately, 27% (n=13) of patients developed stage IV disease, and 25% (n=12) died from melanoma.

In total, 40 (83%) melanomas were primarily cutaneous, and eight (17%) were mucosal, ocular, or melanomas with unknown primary (MUP). Of 40 melanomas on the skin, 75% (n=30) were present in acral regions, primarily the plantar foot or heel. Of acral-site melanomas, 33% (n=10) were acral lentiginous melanomas (ALM), 40% (n=12) were melanomas in situ, three percent (n=1) were spindle cell melanomas, and seven (23%) were not otherwise specified (NOS).

Of 10 non-acral cutaneous melanomas, three were of the superficial-spreading type (SSM), and three were of the desmoplastic variety. Compared to individuals with acral melanomas, those with cutaneous melanomas on non-acral sites showed an increased likelihood of being immunosuppressed [four out of 10 (40%) versus two out of 30 (7.0%)] or having a prior cancer history [six out of 10 (60%) versus five out of 30 (17%)], with all three SSM patients having a history of both. No participant had multiple primary melanomas.

Individuals with advanced-stage acral melanomas, ocular/mucosal melanomas, or MUP were unresponsive to immunotherapeutic agents and showed the poorest outcomes. No individuals with cutaneous melanoma on non-acral sites developed distant metastatic lesions or died from melanoma.

The median duration from tumor diagnosis to hospice/death among melanoma patients was 29 months. Patients had a prior history of uncontrolled HIV infections, multiple myeloma, and pancreatic cancer. Two patients with a previous history of multiple myeloma required autologous stem-cell transplantation within five years. Two patients had germline variants in BReast CAncer gene 2 (BRCA2) and MutS homolog 6 (MSH6), while others had a prior medical history of other tumors.

Cutaneous melanomas on non-acral sites developed from lesional precursors and showed high five-year survival rates (100%) compared to acral cutaneous melanomas (78%), 40% for ocular/mucosal melanomas, and zero percent for MUP. Twelve patients were deceased or initiated hospice without follow-ups due to metastasis, of whom most were receptor tyrosine kinase (c-KIT), serine/threonine-protein kinase B-Raf (BRAF), or neuroblastoma RAS viral oncogene homolog (NRAS) wild-type.

Conclusion

Overall, the study findings showed that most black patients develop melanoma on the acral skin, with 74% of cutaneous-type melanomas and 63% on the plantar foot or heel. Forty percent of cutaneous melanomas on non-acral regions were reported in immunosuppressed individuals. Genetic predisposition and the female sex may contribute to melanoma development in black individuals. A high percentage of black patients presented with regional or distant stages and poor therapy responses for mucosal and acral melanomas. Focusing on improving therapeutic and prevention strategies for these subtypes could potentially improve melanoma mortality in black patients.