## Abstract

Background: It is not yet clear whether increasing melanoma incidence is real or whether recent incidence trends mainly reflect improved diagnosis. To address this question, we examined the most recent melanoma incidence patterns among the white population stratified by sex, age, tumor stage, and tumor thickness by use of data from the Surveillance, Epidemiology, and End Results Program. Methods: We examined log-transformed age-specific rates for melanoma by 5-year age groups and time periods by year of diagnosis and birth cohort. Melanoma trends were further examined among broader age groups (<40 years, 40–59 years, and ≥60 years) by tumor stage and tumor thickness. Rates were age-adjusted to the 1970 U.S. standard population, and trends were tested by use of a two-sided Student's t test. Results: Melanoma incidence increased in females born since the 1960s. From 1974–1975 through 1988–1989, upward trends for the incidence of localized tumors and downward trends for the incidence of distant-stage tumors occurred in the age group under 40 years. In the more recent time period, 1990–1991 through 1996–1997, agespecific rates among females compared with males generally remained stable or declined more for distant-stage tumors and increased less for local-stage tumors. Thin tumors (<1 mm) increased statistically significantly in all age groups (P<.05 for all), except in men under age 40 years. In contrast, rates for thick tumors (≥4 mm) increased statistically significantly (P = .0003) only in males aged 60 years and older. Conclusion: Melanoma incidence may well continue to rise in the United States, at least until the majority of the current population in the middle-age groups becomes the oldest population. The recent trends may reflect increased sunlight exposure.

Skin melanoma is among the most rapidly increasing cancers among the white population in the United States (1), although the rate of increase in the incidence rate appears to be declining. The lifetime risk of being diagnosed with melanoma is 1.91% in white men and 1.37% in white women (2). Sun exposure in childhood (3) and intense intermittent sun exposures (47) are suggested to be the major environmental risk factors. We recently reported the changing geographic patterns of mortality from melanoma on the basis of data from 1950 through 1994 (8). In the investigation presented in this article, we analyze the incidence patterns of melanoma stratified by sex, age, tumor stage, and tumor thickness to determine whether the increasing melanoma incidence is real or whether the increasing recent trends mainly reflect improved diagnosis.

## Methods

Incidence data for invasive melanoma were obtained from the Surveillance, Epidemiology, and End Results (SEER)1

1

Editor's note: SEER is a set of geographically defined, population-based, central cancer registries in the United States, operated by local nonprofit organizations under contract to the National Cancer Institute (NCI). Registry data are submitted electronically without personal identifiers to the NCI on a biannual basis, and the NCI makes the data available to the public for scientific research.

Program; data for in situ melanoma were excluded from analyses. Annual sex-specific and age-adjusted rates using the 1970 U.S. standard population were calculated and then plotted by year of diagnosis. Their trends were assessed by a joinpoint regression model (9), which characterizes changing trends over successive segments of time and the amount of increase or decrease within each segment. To describe age-specific trends by year of diagnosis and year of birth, we computed rates by 5-year age groups (15–19 years, 20–24 years, … , 80–84 years, and 85 years or older) and by 5-year time periods (from 1973–1977 through 1993–1997); 5-year (grouped and averaged) rates provide more stable rates. Then we plotted the rates by calendar year of diagnosis (middle year of the 5-year group) or calendar year of birth by use of a logarithmic scale for the ordinate (10).

We also fitted a formal age–period–cohort model (11) to these data to evaluate changes in the slope of incidence trends by birth cohort. The change in the slope (C) was quantified by use of the identifiable parameter (12,13) centered on birth-cohort j as defined by

$\mathit{C}\ {=}\ {(}3{\gamma}_{\mathit{j}{+}3}\ {+}\ {\gamma}_{\mathit{j}{+}2}\ {-}\ {\gamma}_{\mathit{j}{+}1}\ {-}\ 3{\gamma}_{\mathit{j}}{)}\ {-}\ {(}3{\gamma}_{\mathit{j}}\ {+}\ {\gamma}_{\mathit{j}\ {-}1}\ {-}\ {\gamma}_{\mathit{j}\ {-}2}\ {-}\ 3{\gamma}_{\mathit{j}\ {-}3}{)},$
where γj denotes the birth-cohort effect identified by birth-cohort j. This parameter compares two linear contrasts, the first contrast characterizing the slope of the birth-cohort curve for the later birth cohorts (j to j + 3) and the second characterizing the slope for the earlier birth cohorts (j – 3 to j). A negative value for this parameter indicates a decrease in the birth-cohort slope around cohort j.

Melanoma cases were categorized into three defined tumor stages: local, regional, and distant (2). Local stage indicates that the cancer is confined to the skin as the primary site, regional stage indicates that the cancer involves regional lymph nodes, and distant stage indicates that the cancer has spread to other organs of the body from its primary site. To examine historic and more recent trends of melanoma by these tumor stages, rates age-adjusted to the 1970 U.S. standard population were computed for age groups: under 40 years, 40–59 years, 60 years and older, and all ages combined for grouped (and averaged) calendar years from 1974–1975 through 1988–1989 and from 1990–1991 through 1996–1997. Estimated annual percent changes (EAPCs) were calculated by fitting a regression line to the natural logarithm of the age-adjusted rates, weighted by the inverse of the estimated variance of the logarithm of age-adjusted rates, using the calendar year as the predictor variable, i.e., y = bx + a, where y = ln (rate), x = calendar year, and a = constant; then the EAPC = (eb – 1)*100. The coefficients, b, were tested for being different from zero by use of the two-sided Student's t test at P<.05 significance level (14).

Information on tumor thickness in the SEER database is available for cases diagnosed since 1988 (15). We categorized invasive melanoma cases according to their thickness into less than 1 mm, 1 to less than 4 mm, and greater than or equal to 4 mm. Then we computed the annual age-adjusted rates from 1988 through 1997 by thickness for all primary lesions for age groups less than 40 years, 40–59 years, 60 years and older, and all ages. We also computed the age-adjusted rates by thickness for only the first primary melanoma. The EAPCs for all primaries were calculated by following the method described above.

## Results

Between 1973 and 1997, 60 541 invasive skin melanoma cases were diagnosed among whites residing in the SEER areas. The incidence rates are expressed as the number of cases per 100 000 person-years of observation. Age-adjusted incidence rates almost tripled among males, from 6.7 in 1973 to 19.3 in 1997, and more than doubled among females, from 5.9 to 13.8 (Fig. 1). Joinpoint analyses showed that the rates rose less steeply in the recent period compared with the earlier period for both males and females. In men, the EAPCs declined from 7.2 between 1973 and 1980 to 3.6 between 1980 and 1997; in women, the EAPCs declined from 6.7 between 1973 and 1980 to 2.2 between 1980 and 1997.

## Discussion

The melanoma incidence has not abated, and melanoma is still among the most rapidly rising cancers in the United States. Older men carry the highest melanoma risk in the United States. Not only did the large proportion of melanoma occur in individuals aged 60 years and older, but also rates of melanoma in the more recent period increased faster in those aged 60 years and above, especially in men. Hence, overall melanoma incidence rates in the United States may well continue to rise for some time into the future.

The elevated birth-cohort risks before 1950 were consistent with previous findings (16), while the increased birth-cohort risks after 1960 among females were unexpected, since prior reports (16,17) suggested stabilized or declined rates for cohorts born after 1950. Although long-term data on sun-exposure behaviors and attitudes in the United States are unavailable to relate them with birth-cohort risks, it has been suggested that the birth-cohort risks of melanoma are the results of sun-exposure behaviors and attitudes of each generation of males and females during childhood and adulthood (8,17). Robinson et al. (18) reported on trends in sun-exposure knowledge, behaviors, and attitudes in the United States on the basis of analysis of survey data from two time periods, 1986 and 1996. The proportion of people who experienced at least one sunburn, the most consistently associated sun-exposure variable with melanoma (19), statistically significantly increased from 30% in 1986 to 39% in 1996. However, data were inadequate to evaluate differences by birth cohort.

The birth-cohort incidence patterns for females born after 1960 were different from the mortality patterns; mortality consistently declined in cohorts born after 1950 (8,17). The birth-cohort mortality patterns in the SEER areas were generally similar to the national birth-cohort mortality patterns (data not shown), with declines among recent cohorts. Increasing melanoma incidence in the face of declining mortality was reported in New Zealand (20), in England (21), and in a number of other European countries (22). Possible factors contributing to the divergence of incidence and mortality rates include changes in diagnostic criteria and improvement in survival. However, there appeared to be little change over time in histopathologic criteria in the diagnosis of melanoma (23,24).

Survival rates for patients with melanoma increased over time in all age groups in the SEER areas (2). For cases diagnosed between 1974–1975 and 1992–1993, the 5-year relative survival increased from 84.5% to 91.5% for ages under 40 years, from 79.4% to 87.51% for ages 40–59 years, from 73% to 88% for ages 60 years and older, and from 79.2% to 88.2% for all ages combined. Furthermore, survival for all ages and sexes combined has changed from 89.1% to 95.6% after localized disease, from 56.5% to 59.5% after regional disease, and from 14.0% to 10% after metastatic disease. The general improvement in survival may be related to greater awareness of melanoma by health professionals and the general public, leading to the detection of the disease at an earlier stage. From 1974–1975 through 1988–1989, upward trends for rates of local-stage tumors with simultaneous downward trends for distant-stage tumors were seen in ages under 40 years (Table 1). This may partly explain the divergence of incidence and mortality among the young birth cohorts. For the older-aged groups, improvements in survival may have contributed to the moderation of the slopes in mortality.

Our analysis of the incidence data by tumor stages and thickness categories agreed with previous reports (25,26). Between 1974–1975 and 1988–1989, overall rates increased statistically significantly (P<.05) for every tumor stage among males and for only local-stage tumor among females (Table 1). In the more recent time period, however, the overall rates increased statisticaly significantly for local- and regional-stage tumors among males but not among females. In general, age-specific rates among males stabilized or declined less for distant-stage tumors for those aged under 60 years and increased more for those aged 60 years and older compared with females. Rates statistically significantly increased for all thickness categories except for the thick lesions among females (Table 2). Because of lower survival rates of patients with distant-stage and thick tumors (27), the preceding trends may explain why overall mortality from melanoma in the United States is still increasing among males but is stabilizing or declining among females. It is also worth noting that improved detection and documentation of tumor thickness, as reflected on proportional reductions in unstaged and unknown thickness categories over time, to some extent may have contributed to the increased incidence in local-stage and thin lesions.

Many reviewers have examined whether improved detection or real occurrence or both have led to the increase in melanoma incidence (8,25,28,29). Earlier detection, resulting mainly from increased awareness by health providers and the general public, has indeed had an impact, as seen in the higher rate of increase in localized tumors compared with regional and metastatic diseases. However, on the basis of our findings and others, there is supporting evidence to suggest that the trends reflect real changes more than increased diagnosis: 1) Incidence increased more rapidly in the 1970s when there was little awareness of melanoma; educational programs to enhance early detection of melanoma at the national level started in 1985 (30). 2) Sun exposure as measured by sunburning and regular use of a tanning booth increased in the past decade (18). 3) In the time period covered by our analyses, 1974–1997, the rise in incidence was not limited to local-stage and thin tumors, with potential misclassifications; distant-stage and thick tumors, with little misclassification, also increased statistically significantly (Fig. 4; Tables 1 and 2). 4) Most important, mortality increased for decades (8,17,25), and there was no major change in the International Causes of Death code for melanoma (31) to account for its increase. 5) It is also noteworthy that melanoma is increasingly diagnosed in nonhospital medical settings, with underreporting as high as 20% of the total cases in some cancer registries (32,33). This, if it did not underestimate the recent trend, may potentially offset misclassification of nevi as invasive melanoma that may have occurred.

In summary, the recent melanoma trends in the United States may reflect increased sun exposure more than increasing diagnosis. Incidence likely will continue to increase, at least until the majority of the current middle-aged population becomes the oldest population. The rise of risk in the more recent birth cohort calls for increased support for primary and secondary prevention programs. However, the current decline or stabilization of rates in distant-stage and thick tumors in males less than 60 years of age may be early indications for peaking of mortality among males in the near future, since it has already been seen among females.

Table 1.

Melanoma incidence trends by age groups and tumor stages, SEER* Program (from 1974–1975 through 1988–1989 and 1990–1991 through 1996–1997)

1974–1975 through 1988–1989 1990–1991 through 1996–1997
Males Females Males Females
Age, y Stage EAPC† P‡ EAPC† P‡ EAPC† P‡ EAPC† P‡
*SEER = Surveillance, Epidemiology, and End Results.
†EAPC = estimated annual percent change.
‡All P values were two-sided.
All Local 6.4 .0001 4.6 .0001 3.5 .0184 3.0 .0773
Regional 2.3 .0358 1.6 .1220 4.4 .0148 3.0 .1711
Distant 2.2 .0010 0.4 .4295 2.0 .3092 0.1 .9739
All 5.1 .0001 3.7 .0002 3.3 .0082 2.7 .0399
<40 Local 3.3 .0078 4.0 .0004 −1.6 .5578 1.6 .2552
Regional 0.5 .2157 −1.4 .4510 −3.9 .3665 9.6 .0270
Distant −0.1 .9753 −4.2 .0599 −3.3 .7064 −1.9 .6590
All 2.4 .0225 3.0 .0013 −2.1 .4236 1.6 .2024
40–59 Local 5.5 .0001 4.4 .0003 2.2 .0462 2.3 .2183
Regional 1.1 .2754 2.1 .1886 5.4 .1049 −1.1 .7986
Distant 2.3 .0549 4.1 .0353 2.8 .2945 −4.0 .0989
All 4.4 .0001 3.7 .0005 2.5 .0059 2.0 .2073
≥60 Local 8.7 .0001 5.7 .0001 5.8 .0150 5.1 .0014
Regional 3.7 .0571 2.0 .1513 5.4 .0210 3.7 .3099
Distant 3.2 .0009 0.2 .8347 2.7 .2597 3.8 .5101
All 7.0 .0001 4.1 .0001 5.2 .0141 4.3 .0149
1974–1975 through 1988–1989 1990–1991 through 1996–1997
Males Females Males Females
Age, y Stage EAPC† P‡ EAPC† P‡ EAPC† P‡ EAPC† P‡
*SEER = Surveillance, Epidemiology, and End Results.
†EAPC = estimated annual percent change.
‡All P values were two-sided.
All Local 6.4 .0001 4.6 .0001 3.5 .0184 3.0 .0773
Regional 2.3 .0358 1.6 .1220 4.4 .0148 3.0 .1711
Distant 2.2 .0010 0.4 .4295 2.0 .3092 0.1 .9739
All 5.1 .0001 3.7 .0002 3.3 .0082 2.7 .0399
<40 Local 3.3 .0078 4.0 .0004 −1.6 .5578 1.6 .2552
Regional 0.5 .2157 −1.4 .4510 −3.9 .3665 9.6 .0270
Distant −0.1 .9753 −4.2 .0599 −3.3 .7064 −1.9 .6590
All 2.4 .0225 3.0 .0013 −2.1 .4236 1.6 .2024
40–59 Local 5.5 .0001 4.4 .0003 2.2 .0462 2.3 .2183
Regional 1.1 .2754 2.1 .1886 5.4 .1049 −1.1 .7986
Distant 2.3 .0549 4.1 .0353 2.8 .2945 −4.0 .0989
All 4.4 .0001 3.7 .0005 2.5 .0059 2.0 .2073
≥60 Local 8.7 .0001 5.7 .0001 5.8 .0150 5.1 .0014
Regional 3.7 .0571 2.0 .1513 5.4 .0210 3.7 .3099
Distant 3.2 .0009 0.2 .8347 2.7 .2597 3.8 .5101
All 7.0 .0001 4.1 .0001 5.2 .0141 4.3 .0149
Table 2.

Melanoma incidence trends by age groups and tumor thickness, SEER* Program (from 1988 through 1997)

Males Females
Age, y Thickness† EAPC‡ P§ EAPC‡ P§
*SEER = Surveillance, Epidemiology, and End Results.
†Tumor thickness categories: thin = less than 1 mm; intermediate = 1–4 mm; thick = greater than or equal to 4 mm.
‡EAPC = estimated annual percent change.
§All P values were two-sided.
All Thin 5.0 .0001 4.1 .0001
Intermediate 4.4 .0009 2.5 .0341
Thick 6.1 .0076 1.0 .6242
All 3.4 .0001 2.5 .0001
<40 Thin 1.6 .2651 2.2 .0057
Intermediate −1.4 .4256 1.7 .3250
Thick −1.8 .7225 3.7 .5867
All −1.0 .4023 1.2 .0701
40–59 Thin 4.4 .0005 3.7 .0008
Intermediate 2.3 .0422 1.0 .3835
Thick 5.3 .0925 −1.1 .7349
All 2.7 .0001 2.0 .0069
≥60 Thin 6.6 .0001 6.7 .0001
Intermediate 7.4 .0001 4.4 .0041
Thick 7.7 .0003 1.2 .6635
All 5.1 .0001 4.3 .0001
Males Females
Age, y Thickness† EAPC‡ P§ EAPC‡ P§
*SEER = Surveillance, Epidemiology, and End Results.
†Tumor thickness categories: thin = less than 1 mm; intermediate = 1–4 mm; thick = greater than or equal to 4 mm.
‡EAPC = estimated annual percent change.
§All P values were two-sided.
All Thin 5.0 .0001 4.1 .0001
Intermediate 4.4 .0009 2.5 .0341
Thick 6.1 .0076 1.0 .6242
All 3.4 .0001 2.5 .0001
<40 Thin 1.6 .2651 2.2 .0057
Intermediate −1.4 .4256 1.7 .3250
Thick −1.8 .7225 3.7 .5867
All −1.0 .4023 1.2 .0701
40–59 Thin 4.4 .0005 3.7 .0008
Intermediate 2.3 .0422 1.0 .3835
Thick 5.3 .0925 −1.1 .7349
All 2.7 .0001 2.0 .0069
≥60 Thin 6.6 .0001 6.7 .0001
Intermediate 7.4 .0001 4.4 .0041
Thick 7.7 .0003 1.2 .6635
All 5.1 .0001 4.3 .0001
Fig. 1.

Age-adjusted (to 1970 U.S. standard population) skin melanoma incidence and 95% confidence intervals (outer lines) among the white population stratified by sex in the Surveillance, Epidemiology, and End Results Program areas from 1973 through 1997.

Fig. 1.

Age-adjusted (to 1970 U.S. standard population) skin melanoma incidence and 95% confidence intervals (outer lines) among the white population stratified by sex in the Surveillance, Epidemiology, and End Results Program areas from 1973 through 1997.

Fig. 2.

Age-specific skin melanoma incidence among the white population stratified by sex and calendar year of diagnosis (middle year of the 5-year group plotted on the x-axis) in the Surveillance, Epidemiology, and End Results Program areas from 1973–1977 through 1993–1997.

Fig. 2.

Age-specific skin melanoma incidence among the white population stratified by sex and calendar year of diagnosis (middle year of the 5-year group plotted on the x-axis) in the Surveillance, Epidemiology, and End Results Program areas from 1973–1977 through 1993–1997.

Fig. 3.

Age-specific skin melanoma incidence among the white population stratified by sex and birth-cohort year in the Surveillance, Epidemiology, and End Results Program areas from 1973–1977 through 1993–1997. The points vertically above each cohort year portray the cohort's age-specific incidence experience.

Fig. 3.

Age-specific skin melanoma incidence among the white population stratified by sex and birth-cohort year in the Surveillance, Epidemiology, and End Results Program areas from 1973–1977 through 1993–1997. The points vertically above each cohort year portray the cohort's age-specific incidence experience.

Fig. 4.

Age-adjusted (to 1970 U.S. standard population) skin melanoma incidence and 95% confidence intervals (outer lines) among the white population stratified by sex and tumor stage in the Surveillance, Epidemiology, and End Results Program areas from 1974–1975 to 1996–1997.

Fig. 4.

Age-adjusted (to 1970 U.S. standard population) skin melanoma incidence and 95% confidence intervals (outer lines) among the white population stratified by sex and tumor stage in the Surveillance, Epidemiology, and End Results Program areas from 1974–1975 to 1996–1997.

We thank Dr. Robert Tarone of the National Cancer Institute (Bethesda, MD) for his advice on data analyses.

## References

1
Ries LA, Wingo PA, Miller DS, Howe HL, Weir HK, Rosenberg HM, et al. The annual report to the nation on the status of cancer, 1973–1997, with a special section on colorectal cancer.
Cancer

2000
;
88
:
2398
–424.
2
Ries LA, Eisner MP, Kosary CL, Hankey BF, Miller BA, Clegg L, et al, editors. SEER Cancer Statistics Review, 1973–1997. Bethesda (MD): National Cancer Institute; 2000.
3
Mack TM, Floderus B. Malignant melanoma risk by nativity, place of residence at diagnosis, and age at migration.
Cancer Causes Control

1991
;
2
:
401
–11.
4
Walter SD, King WD, Marrett LD. 1999. Association of cutaneous malignant melanoma with intermittent exposure to ultraviolet radiation: results of a case–control study in Ontario, Canada.
Int J Epidemiol

1999
;
28
:
418
–27.
5
Fears TR, Scotto J, Schneiderman MA. Mathematical model of age and ultraviolet effects on the incidence of skin cancer among whites in the United States.
Am J Epidemiol

1977
;
105
:
420
–7.
6
Osterlind A, Tucker MA, Stone BJ, Jensen OM. The Danish case–control study of cutaneous malignant melanoma. II. Importance of UV-light exposure.
Int J Cancer

1988
;
42
:
319
–24.
7
Gilchrest BA, Eller MS, Geller AC, Yaar M. The pathogenesis of melanoma induced by ultraviolet radiation.
N Engl J Med

1999
;
340
:
1341
–8.
8
Jemal A, Devesa SS, Fears TR, Hartge P. Cancer surveillance series: changing patterns of cutaneous malignant melanoma mortality rates among whites in the United States.
J Natl Cancer Inst

2000
;
92
:
811
–8.
9
Kim HJ, Fay MP, Feuer EJ, Midthune DN. Permutation tests for joinpoint regression with applications to cancer rates
Stat Med

2000
;
19
:
335
–51.
10
Devesa SS, Donaldson J, Fears T. Graphical presentation of trends in rates.
Am J Epidemiol

1995
;
141
:
300
–4.
11
McCullagh P, Nelder JA. Generalized linear models. New York: Chapman & Hall; 1989.
12
Tarone RE, Chu KC. Evaluation of birth cohort patterns in population disease rates.
Am J Epidemiol

1996
;
143
:
85
–91.
13
Snedecor GW, Cochran WG. Statistical methods. 7th ed. Ames (IA): The Iowa State University Press; 1980. p. 491.
14
SAS Institute Inc. SAS/STAT user's guide. Version 6. 4th ed. Vol. 2. Cary (NC): SAS Institute Inc.; 1989.
15
Fritz A, Ries LA, editors. SEER extent of diseases—1988. Codes and coding instructions. 3rd ed. Bethesda (MD): National Cancer Institute; 1998.
16
Dennis LK, White E, Lee JA. Recent cohort trends in malignant melanoma by anatomic site in the United States.
Cancer Causes Control

1993
;
4
:
93
–100.
17
Scotto J, Pitcher H, Lee JA. Indications of future decreasing trends in skin-melanoma mortality among whites in the United States.
Int J Cancer

1991
;
49
:
490
–7.
18
Robinson JK, Rigel DS, Amonette RA. Trends in sun exposure knowledge, attitudes, and behaviors: 1986 to 1996.

1997
;
37
(2 Pt 1):
179
–86.
19
Armstrong BK, English DR. Cutaneous malignant melanoma. In: Schottenfeld D, Fraumeni JF Jr, editors. Cancer epidemiology and prevention. 2nd ed. New York (NY): Oxford University Press; 1996. p. 1282–312.
20
Cooke KR, Skegg DC, Fraser J. Trends in malignant melanoma of skin in New Zealand.
Int J Cancer

1983
;
31
:
715
–8.
21
Streetly A, Markowe H. Changing trends in the epidemiology of malignant melanoma: gender differences and their implications for public health.
Int J Epidemiol

1995
;
24
:
897
–907.
22
Armstrong BK, Kricker A. Cutaneous melanoma.
Cancer Surv

1994
;
19–20
:
219
–40.
23
Philipp R, Hastings A, Briggs J, Sizer J. Are malignant melanoma time trends explained by changes in histopathological criteria for classifying pigmented skin lesions?
J Epidemiol Community Health

1988
;
42
:
14
–6.
24
van der Esch EP, Muir CS, Nectoux J, Macfarlane G, Maisonneuve P, Bharucha H, et al. Temporal change in diagnostic criteria as a cause of the increase of malignant melanoma over time is unlikely.
Int J Cancer

1991
;
47
:
483
–9.
25
Dennis LK. Analysis of the melanoma epidemic, both apparent and real: data from the 1973 through 1994 Surveillance, Epidemiology, and End Results Program registry.
Arch Dermatol

1999
;
135
:
275
–80.
26
Hall HI, Miller DR, Rogers JD, Bewerse B. Update on the incidence and mortality from melanoma in the United States.

1999
;
40
:
35
–42.
27
Schuchter L, Schultz DJ, Synnestvedt M, Trock BJ, Guerry D, Elder DE, et al. A prognostic model for predicting 10-year survival in patients with primary melanoma. The Pigmented Lesion Group.
Ann Intern Med

1996
;
125
:
369
–75.
28
Swerlick RA, Chen S. The melanoma epidemic: more apparent than real?
Mayo Clin Proc

1997
;
72
:
559
–64.
29
Glass AG, Hoover RN. The emerging epidemic of melanoma and squamous cell skin cancer.
JAMA

1989
;
262
:
2097
–100.
30
Koh HK, Norton LA, Geller AC, Sun T, Rigel DS, Miller DR, et al. Evaluation of the American Academy of Dermatology's National Skin Cancer Early Detection and Screening Program.

1996
;
34
:
971
–8.
31
World Health Organization (WHO). Manual of the international statistical classification of diseases, injuries, and causes of death. Vol 1. 9th rev. Geneva (Switzerland): WHO; 1977.
32
Merlino LA, Sullivan KJ, Whitaker DC, Lynch CF. The independent pathology laboratory as a reporting source for cutaneous melanoma incidence in Iowa, 1977–1994.

1997
;
37
:
578
–85.
33
Koh HK, Clapp RW, Barnett JM, Nannery WM, Tahan SR, Geller AC, et al. Systematic underreporting of cutaneous malignant melanoma in Massachusetts. Possible implications for national incidence figures.