Incidence trends of lentigo maligna and lentigo maligna melanoma in the United States from 2000 to 2019

BACKGROUND

Information on lentigo maligna (LM) and lentigo maligna melanoma (LMM) in the 21st century is scarce. We aimed to elucidate the incidence of LM and LMM using the Surveillance, Epidemiology, and End Results (SEER) 17 Registries.

METHODS

The data of patients diagnosed between 2000 and 2019 were extracted from the SEER database. The percentage of LM/LMM cases among all melanoma patients, age-standardized incidence rates, estimated annual percentage changes, and the cumulative incidence of LMM after LM were calculated.

RESULTS

The SEER data yielded 95,175 patients with LM/LMM between 2000 and 2019. Cases of LM/LMM accounted for 15.7% of all melanomas. The age-standardized incidence per 100,000 person-years for LM increased from 4.16 to 5.61 and for LMM from 1.33 to 2.35 between 2000 and 2019. The annual increase in incidence of LM was 2.42%, and that of LMM was 3.32%. The cumulative incidence of LMM after a primary LM after 10-year follow-up was 0.94%.

CONCLUSIONS

This study provides the first comprehensive analysis of the epidemiological status of LM/LMM in the United States in the 21st century using the population-based SEER data.

Lentigo maligna: a review

Lentigo maligna (LM) is a melanoma in situ with distinct clinical features and histology. It commonly affects men after the sixth decade of life. Incidence rates of LM have increased based on early 21st century data from different countries; however, data are suboptimal. Data from England show a plateauing crude incidence between 2013 and 2019. By comparison, invasive melanoma and other types of melanoma in situ commonly appears in younger age groups (median age 58 and 67 years old, respectively) and incidence is rising. The most important risk factors for LM include fair skin and cumulative ultraviolet solar radiation exposure. Although LM is limited to the epidermis and connected skin adnexa, it may progress to invasive LM melanoma. The reported rate of malignant progression varies, reflecting a challenge for LM epidemiology research as often lesions are removed on diagnosis. LM poses a challenge in diagnosis and management. Although it can be diagnosed clinically or dermoscopically, histopathological assessment of biopsied skin tissue remains the gold standard. Reflectance confocal microscopy allows for better appreciation of the complexity of LM at a cellular level, often progressing beyond clinical margins. Management of LM may involve Mohs micrographic surgery or excision, although recurrence may occur even with 5 mm clinical margins. Imiquimod cream may be effective, but incomplete treatment and recurrence has been reported. Conservative management with observation or radiotherapy may be used in selected patients' cases. Five-year net survival rates are excellent. This paper reviews the natural history, epidemiology, aetiology, pathogenesis, diagnosis and management of LM.

Trends in the diagnosis and clinical features of melanoma in situ (MIS) in US men and women: A prospective, observational study

BACKGROUND

The incidence of melanoma in situ (MIS) is increasing, but little is known about its clinical and epidemiologic features.

OBJECTIVE

We sought to determine trends in diagnosis and clinical features of MIS.

METHODS

Incident cases of melanoma were collected prospectively from the Nurses' Health Study (1976-2010) and Health Professionals Follow-up Study (1986-2010).

RESULTS

MIS incidence increased from 2 to 42 per 100,000 person-year among women, and from 11 to 73 per 100,000 person-year among men, exceeding the rate of increase of invasive melanomas. Melanoma mortality initially increased during the follow-up period then plateaued. Men were more likely than women to develop in situ melanomas on the upper half of the body (P < .001). Invasive melanomas were diagnosed at a younger age than MIS (P < .001), and were more likely to be found on the lower extremities than MIS (P < .001).

LIMITATIONS

This is a strictly descriptive study without examination into mechanisms.

CONCLUSION

We found epidemiologic and clinical differences for in situ and invasive melanomas, which support further examination into the variations in etiologic pathways. The lack of improvement in mortality despite the increase in detection of in situ relative to invasive lesions further highlights the need to improve invasive melanoma-specific clinical screening features.

Incidence of lentigo maligna in Olmsted County, Minnesota, 1970 to 2007

BACKGROUND

The incidence of lentigo maligna (LM) may be increasing, but no population-based epidemiologic studies have been performed to our knowledge.

OBJECTIVE

We sought to determine the incidence of LM in Olmsted County, Minnesota, along with overall and recurrence-free survival.

METHODS

Using the Rochester Epidemiology Project, we identified all adult residents of Olmsted County, Minnesota, with a first lifetime diagnosis of LM between 1970 and 2007. Medical records were reviewed to determine demographic, clinical, and surgical data, and incidence and survival were calculated.

RESULTS

Among 145 patients identified, median (range) age at diagnosis of LM was 70 (33-97) years. Treatment changed over time, with Mohs micrographic surgery becoming available after 1986. No patients died of LM; 5 had local recurrence. Estimated local recurrence-free survival at 5, 10, 15, and 20 years after diagnosis was 98%, 96%, 92%, and 92%, respectively. Overall age- and sex-adjusted incidence of LM among adults was 6.3 per 100,000 person-years, increasing from 2.2 between 1970 and 1989 to 13.7 between 2004 and 2007.

LIMITATIONS

Retrospective study design and homogeneous population are limitations.

CONCLUSION

The incidence of LM increased significantly among residents of Olmsted County, Minnesota, over an extended time frame, with incidence being significantly higher among men than women and increasing with age.

Lentigo maligna melanoma--the review

Lentigo maligna melanoma (LMM) is a slowly growing tumor of elderly white population. It typically develops on chronically sun-exposed skin of the head and neck area which indicates that the cumulative exposure to the UV radiation has crucial role in the development of LMM. Precursor lesion is lentigo maligna (LM) which commonly presents as an irregular brownish pigmented macular lesion persisting for years. Women are affected more often as men by LMM, with the average age of over 60 years. The age of onset has dropped over the past years and this tumour is nowadays also diagnosed in 40-year-old individuals. However, the incidence rate increases with age and peaks in the seventh and eighth decades of life. The prognosis for invasive lentigo maligna melanoma does not differ from that for other histogenetic types of melanoma after controlling for tumour thickness. The diagnosis and treatment of LMM remain challenging. In this presentation, we review the epidemiology, clinical presentation, histopathology, and treatment of LMM.

Increasing incidence of lentigo maligna melanoma subtypes: northern California and national trends 1990-2000

Worldwide, lentigo maligna melanoma (LMM) comprises 4%-15% of cutaneous melanoma and occurs less commonly than superficial spreading or nodular subtypes. We assessed the incidence of melanoma subtypes in regional and national Surveillance, Epidemiology, and End Results (SEER) cancer registry data from 1990 to 2000. Because 30%-50% of SEER data were not classified by histogenetic type, we compared the observed SEER trends with an age-matched population of 1024 cases from Stanford University Medical Center (SUMC) (1995-2000). SEER data revealed lentigo maligna (LM) as the most prevalent in situ subtype (79%-83%), and that LMM has been increasing at a higher rate compared with other subtypes and to all invasive melanoma combined for patients aged 45-64 and > or =65 y. The SUMC data demonstrated LM and LMM as the only subtypes increasing in incidence over the study period. In both groups, LM comprised > or =75% of in situ melanoma and LMM > or =27% of invasive melanoma in men 65 y and older. Regional and national SEER data suggest an increasing incidence of LM and LMM, particularly in men > or =age 65. An increased incidence of LM subtypes should direct melanoma screening to heavily sun-exposed sites, where these subtypes predominate.

Malignant melanoma in Taiwan: a prognostic study of 181 cases

This study was performed to determine the characteristics and clinical outcome of patients with cutaneous malignant melanoma in Taiwan. The medical records of patients with primary cutaneous melanoma between 1992 and 2001 at Chang Gung Memorial Hospital (CGMH) were retrieved from the cancer registry. Survival was analysed by the Kaplan-Meier method. Univariate and multivariate analyses of factors associated with survival were performed using the Cox proportional hazard model. One hundred and eighty-one cases were retrieved from the cancer registry of CGMH. The male to female ratio was 1 : 1.13. The most common age of onset was the sixth decade. The median age of onset was 61 years (2-95 years). There were 105 cases (58%) of acral lentiginous melanoma (ALM), 55 cases (30.4%) of nodular melanoma (NM), 19 cases (10.5%) of superficial spreading melanoma (SSM) and two cases (1.1%) of lentigo maligna melanoma. The median survival of the 181 patients was 3.71 years, and the 5-year survival rate was 45.63%. Five-year survival rates of patients with stages I, II, III and IV disease were 84.39%, 56.03%, 34.7% and 0%, respectively. Sex, Breslow thickness, Clark's level, pathological type and age were significant prognostic factors. There were no survival differences between ALM and NM. Both ALM and NM were associated with a poor prognosis when compared with SSM. In conclusion, ALM is the most common type of cutaneous malignant melanoma in Taiwan. The prognostic factors in Taiwan are similar to those in melanoma-prevalent countries.

Management of Lentigo Maligna and Lentigo Maligna Melanoma With Staged Excision

OBJECTIVE

To assess the long-term cure rate for treatment of lentigo maligna (LM) and lentigo maligna melanoma (LMM) by means of a staged, margin-controlled, vertical-edged excision with rush permanent specimens and a radial sectioning technique.

DESIGN

Retrospective follow-up study.

SETTING

University-affiliated and private-practice dermatologic surgery clinics.

PATIENTS

Fifty-nine patients treated for 55 LMs and 7 LMMs between January 1, 1990, and December 31, 2001.

INTERVENTIONS

The technique included vertical excision with initial 2- to 3-mm margins examined by rush permanent sections (prepared and read within 24 hours). Further excision took place as guided by histologic findings. Data on patient and lesion characteristics were obtained via a medical chart review. Patients were then contacted and examined for local recurrence. Biopsies were performed on all patients with possible recurrence on clinical examination.

MAIN OUTCOME MEASURES

Local recurrence of LM or LMM.

RESULTS

After a mean follow-up of 57 months (median, 54 months; 293.8 person-years), 95% of patients were free of recurrence. Three patients had local recurrence and no patients had evidence of metastasis. Two of the 3 local recurrences were of previously excised LM, and 1 was of an LMM. Half (32) of all lesions required 2 or more stages. One required more than 4 stages. The average margin of excision was 0.55 cm. Three of the 58 lesions read as LM on biopsy were found to have invasive disease (LMM) at the time of definitive excision.

CONCLUSIONS

The technique described herein for the treatment of LM and LMM provides a long-term disease-free survival of 95%. The cure rate is greater than that reported for standard excision and is similar to that for other margin-control techniques. To our knowledge, this is the largest reported study and has the longest follow-up for this excision method for LM and LMM.

[Dubreuilh melanoma: and epidemiologic and prognostic study]

BACKGROUND

Lentigo maligna melanoma is a specific histoclinical type of melanoma. We studied the epidemiologic features of lentigo maligna melanoma (Dubreuilh's melanoma) and compared prognosis with other types of melanoma.

PATIENTS AND METHODS

A retrospective review of 516 cases of cutaneous melanomas, seen from 1985 to 1997, identified 29 cases of lentigo maligna melanoma. Epidemiologic, clinical and prognostic data were collected using a common scoring system for all patients. The chi-squared test, univariate log rank analysis, Cox multiple regression model for multivariate analysis, and actuarial survival curves were applied.

RESULTS

The 29 cases of lentigo maligna melanoma (16 women, 13 men) accounted for 5.9 p. 100 of all melanomas. Mean age at diagnosis was 73 years compared with 54 years for others melanomas. Predominant localization was head and neck. There was no prior history of nevi compared with 50 p. 100. Mean delay to diagnosis was 4 years versus 1 year. All patients have had an occupation with to sun exposure. Mean tumoral thickness was 2 mm. Survival was the same as for extensive superficial melanomas and better than for nodular melanomas. Multivariate analysis showed that prognosis was not better in case of lentigo maligna melanoma. Tumoral thickness was the main prognosis factor.

DISCUSSION

Our findings confirmed the specific nature of lentigo maligna melanoma and suggested that sun exposure plays an important role. Multivariate analysis did not show that prognosis was any better in case of lentigo maligna melanoma than in other types of melanoma. The thickness of the tumor must be taken into account as for other melanomas.

Clinical and histologic trends of melanoma

BACKGROUND

Several changing clinical and histopathologic melanoma trends occurred from the 1950s to the 1980s.

OBJECTIVE

The purpose of this study was to evaluate melanoma trends during the past decade and to compare present trends to those documented during the past four decades.

METHODS

Sex, age at diagnosis, location, tumor thickness, stage, and histologic subtypes were evaluated from 1984 to 1995 and compared with trends during the past four decades.

RESULTS

Most changing trends from the past four decades have slowed or stabilized during the past decade.

CONCLUSION

Complete reporting of all melanomas to central tumor registries is necessary to accurately analyze present and future melanoma trends. Ongoing and new prevention and control strategies beginning at birth may be necessary to continue the positive efforts to curtail the melanoma epidemic.

Small cell (naevoid) melanoma: a clinicopathologic study of 131 cases

One hundred and thirty-one small cell melanomas were reviewed with respect to clinical data submitted with each specimen and the histological pattern of each tumour. Of the small cell melanomas, 80% developed in individuals over the age of 50 years. There was a 2:1 male predominance with 58% of the tumours in men occurring on the back. All but one melanoma showed a lentiginous intraepidermal pattern. The dermal component was characterized by cords and nests of hyperchromatic melanocytes associated with interstitial fibrosis. Small cell melanomas may be recognized as thin lesions and are commonly located in chronic sun-damaged skin of elderly individuals. They may represent a special naevoid variant of lentigo maligna melanoma.

Comparison between lentigo maligna melanoma and other histogenetic types of malignant melanoma of the head and neck. Scottish Melanoma Group

A study of 953 invasive cutaneous malignant melanomas of the head and neck was performed to determine differences between lentigo maligna melanoma and other histogenetic types with regard to patients and sites affected; prognosis was analysed in 595 of these cases. The cases studied comprised all head and neck melanomas registered with the Scottish Melanoma Group between 1979 and 1992, apart from the 3% of cases that were unclassifiable or rare histogenetic types. The histogenetic types of melanoma were 498 (52%) lentigo maligna melanoma (LMM), 237 (25%) superficial spreading melanoma (SSM) and 218 (23%) nodular melanoma (NM). All types increased in incidence throughout the study period. Patients with LMM (mean age 73 years) and NM (mean 68 years) were significantly older than those with SSM (mean 57 years). There were significant anatomical subsite differences related to sex of patients and histogenetic type of melanoma; melanomas on the face were more frequent in females and 90% of LMM occurred at this site, whereas melanomas on the scalp, neck and ears were more frequent in men. Kaplan-Meier estimates of the probability of survival were produced for the 595 of these 953 patients with 5 year follow-up details. In this group of patients the prognostic significance of tumour thickness, Clark level of invasion, ulceration, histogenetic type of melanoma and number of mitoses were studied using stepwise variable selection of procedures. Each of these possible prognostic factors attained individual significance but the tumour thickness was the dominant risk factor in the proportional hazards analysis. When patients were divided into four sex/ulceration subgroups (male/ulcerated, female/ulcerated, male/non-ulcerated, female/non-ulcerated) and analysed by proportional hazards analysis, no variable other than the tumour thickness had any further prognostic effect. Histogenetic type did not remain an independent prognostic variable at this stage. Despite sex and subsite differences, the prognosis for invasive lentigo maligna melanoma does not differ from that for other histogenetic types after controlling for tumour thickness.

Lentigo maligna and lentigo maligna melanoma

Lentigo maligna (LM) is a pigmented lesion that occurs on the sun-exposed skin, particularly the head and neck areas, of an older patient. The lesion increases in size and at some point, often many years after its onset, may become lentigo maligna melanoma (LMM). For this reason, most authors consider LM a form of melanoma in situ. Treatment includes surgical or destructive modalities; the preferred form of therapy is surgical removal. Histopathologic features include a proliferation of atypical melanocytes along the basal layer of the epidermis and adnexal structures. This article discusses the clinical, histopathologic, and epidemiologic features of LM. The prognosis and treatment of LM are reviewed. Although the lifetime risk of the development of LMM is unclear, LMM is discussed briefly.

Trends in prognostic factors of melanoma in South Australia, 1981-1992: implications for health promotion

OBJECTIVE

To analyse trends in prognostic factors at diagnosis of melanoma to indicate targets for health promotion.

METHODS

Cases of melanoma notified to the South Australian Cancer Registry during 1981-1992 (1361 in situ and 4509 invasive) were analysed by tumour site, histological type, stage, thickness, period of diagnosis and sociodemographic characteristics of the patient.

RESULTS

The relative probability of being diagnosed with an in-situ, rather than a thin invasive, lesion increased progressively between 1984-1986 and 1990-1992. The relative probability of having an in-situ melanoma diagnosed was: lower among those aged 80 years or more; higher among patients residing in the upper socioeconomic areas of Adelaide; high for lesions on the face; and high for lentigo maligna as opposed to superficial spreading lesions. The relative probability of invasive lesions being diagnosed when more than 1.5 mm thick decreased progressively between the 1981-1983 and 1990-1992 diagnosis periods. The relative probability of thick lesions being diagnosed was higher among older patients and for nodular lesions compared with superficial spreading or lentigo maligna lesions. Facial lesions and those in males tended to be thicker.

CONCLUSIONS

There are favourable trends towards earlier detection of melanomas in South Australia, probably reflecting the effect of skin-cancer awareness campaigns. Further campaigns should emphasise early detection in people aged 60 years and over, males and residents of less affluent areas. Early detection of nodular melanomas and invasive lesions of the face also warrants special attention.