Melanoma incidence continues to increase, yet mortality stabilizing
This story appears courtesy of MDedge News
EXPERT ANALYSIS FROM SDEF LAS VEGAS DERMATOLOGY SEMINAR
LAS VEGAS – The incidence of melanoma in the United States continues to increase, yet mortality from the disease has been stable and may even be starting to decline, according to data from the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program.
At the Skin Disease Education Foundation’s annual Las Vegas Dermatology Seminar, Laura Korb Ferris, MD, PhD, said that SEER data project 96,480 new cases of melanoma in 2019, as well as 7,230 deaths from the disease. In 2016, SEER projected 10,130 deaths from melanoma, “so we’re actually projecting a reduction in melanoma deaths,” said Dr. Ferris, director of clinical trials at the University of Pittsburgh Medical Center’s department of dermatology. She added that the death rate from melanoma in 2016 was 2.17 per 100,000 population, a reduction from 2.69 per 100,000 population in 2011, “so it looks like melanoma mortality may be stable,” or even reduced, despite an increase in melanoma incidence.
A study of SEER data between 1989 and 2009 found that melanoma incidence is increasing across all lesion thicknesses (J Natl Cancer Inst. 2015 Nov 12. doi: 10.1093/jnci/djv294). Specifically, the incidence increased most among thin lesions, but there was a smaller increased incidence of thick melanoma. “This suggests that the overall burden of disease is truly increasing, but it is primarily stemming from an increase in T1/T2 disease,” Dr. Ferris said. “This could be due in part to increased early detection.”
Improvements in melanoma-specific survival, she continued, are likely a combination of improved management of T4 disease, a shift toward detection of thinner T1/T2 melanoma, and increased detection of T1/T2 disease.
The SEER data also showed that the incidence of fatal cases of melanoma has decreased since 1989, but only in thick melanomas. This trend may indicate a modest improvement in the management of T4 tumors. “Optimistically, I think increased detection efforts are improving survival by early detection of thin but ultimately fatal melanomas,” Dr. Ferris said. “Hopefully we are finding disease earlier and we are preventing patients from progressing to these fatal T4 melanomas.”
Disparities in melanoma-specific survival also come into play. Men have poorer survival compared with women, whites have the highest survival, and non-Hispanic whites have a better survival than Hispanic whites, Dr. Ferris said, while lower rates of survival are seen in blacks and nonblack minorities, as well as among those in high poverty and those who are separated/nonmarried. Lesion type also matters. The highest survival is seen in those with superficial spreading melanoma, while lower survival is observed in those with nodular melanoma, and acral lentiginous melanoma.
Early detection of thin nodular melanomas has the potential to significantly impact melanoma mortality, “but we want to keep in mind that the majority of ultimately fatal melanomas are superficial spreading melanomas,” Dr. Ferris said. “That is because they are so much more prevalent. As a dermatologist, I think a lot about screening and early detection. Periodic screening is a good strategy for a slower-growing superficial spreading melanoma, but it’s not necessarily a good strategy for a rapidly growing nodular melanoma. That’s going to require better education and better access to health care.”
Self-detection of melanoma is another strategy to consider. According to Dr. Ferris, results from multiple studies suggest that about 50% of all melanomas are detected by patients, but the ones they find tend to be thicker than the ones that clinicians detect during office visits. “It would be great if we can get that number higher than 50%,” Dr. Ferris said. “If patients really understood what melanoma is, what it looks like, and when they needed to seek medical attention, perhaps we could get that over 50% and see self-detection of thinner melanomas. That’s a very low-cost intervention.”
Targeted screening efforts that stratify by risk factors and by age “makes screening more efficient and more cost-effective,” she added. She cited one analysis, which found that clinicians need to screen 606 people and conduct 25 biopsies in order to find one melanoma. “That’s very resource intensive,” she said. “However, if you only screened people 50 or older or 65 or older, the number needed to screen goes down, and because your pretest probability is higher, your number need to biopsy goes down as well. If you factor in things like a history of atypical nevi or a personal history of melanoma, those patients are at a higher risk of developing melanoma.”
Dr. Ferris closed her presentation by noting that Australia leads other countries in melanoma prevention efforts. There, the combined incidence of skin cancer is higher than the incidence of any other type of cancer. Four decades ago, Australian health officials launched SunSmart, a series of initiatives intended to reduce skin cancer. These include implementation of policies for hat wearing and shade provision in schools and at work, availability of more effective sunscreens, inclusion of sun protection items as a tax-deductible expense for outdoor workers, increased availability since the 1980s of long-sleeved sun protective swimwear, a ban on the use of indoor tanning since 2014, provision of UV forecasts in weather, and a comprehensive program of grants for community shade structures (PLoSMed. 2019 Oct 8;16:e1002932).
“One approach to melanoma prevention won’t fit all,” she concluded. “We need to focus on prevention, public education to improve knowledge and self-detection.”
Dr. Ferris disclosed that she is a consultant to and an investigator for DermTech and Scibase. She is also an investigator for Castle Biosciences.
SDEF and this news organization are owned by the same parent company. Dr. Ferris spoke during a forum on cutaneous malignancies at the meeting.
By Doug Brunk