Extending Medicare Coverage for Preventive and Other Services (2000) / Chapter Skim
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Appendix B: Screening for Skin Cancer
Appendix B: Screening for Skin Cancer
Pages 172-221
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From page 172... ...
INTRODUCTION In the United States in 1999, approximately one million new cases of basal cell and squamous cell carcinoma, and about 44,000 new cases of malignant melanoma, are expected to be diagnosed. Malignant melanoma is often lethal, and its incidence in the United States has increased rapidly over the past two decades.
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From page 173... ...
Men over 65 years of age, who constitute 5.2 percent of the U.S. population, have 22 percent of newly diagnosed malignant melanomas each year; women over 65 who constitute 7.4 percent of the population, have 14 percent.
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From page 174... ...
During this time, the rate of diagnosis of "early" or thin melanoma increased sharply, but so did the incidence of thicker (>3 mm) melanomas.5 Changes over time in ascertainment, diagnostic criteria, self-examination, and registry procedures make it difficult to draw reliable inferences about the effectiveness of early detection from epidemiologic data.5-7 In an analysis of trends in Australia and New Zealand, Burton and colleagues noted that although there has been a huge increase in the incidence of very thin melanomas, the incidence of thick melanomas has increased as well.8 Some experts interpret this to mean that increased surveillance in the population may detect a relatively unaggressive, unimportant type of thin melanoma.7-~0 Increased detection of these very thin, nonmetastasizing melanomas would increase the incidence and five-year survival rates for melanoma but would have little impact on mortality.
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From page 175... ...
Squamous cell carcinoma occurred at half the rate of basal cell carcinoma among men and at about one-third the rate among women. In Geraldton, Western Australia, the estimated incidence of basal cell carcinoma was 1,335 per 100,000 in men and 817 per 100,000 in women.~3 In that community, the prevalence of nonmelanoma skin cancer in men and women
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From page 176... ...
This study looked at incidence rates for two time periods, 1979-1980 and 1993-1994.~6 In men, the age-adjusted incidence of basal cell cancer increased from 170 per 100,000 in 1979-1980 to 310 per 100,000 in 1993-1994; and in women basal cell cancer incidence rose from 91 to 166 per 100,000 over the same period. For squamous cell cancer, incidence rates in men rose from 29 to 97 per 100,000 over these periods, and in women, squamous cell cancer incidence rose from 7 to 32 per 100,000.
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From page 177... ...
Thickness of the melanoma also guides the choice of therapy. Nonmelanoma Skin Cancers Basal cell carcinoma and squamous cell carcinoma are the most common forms of skin cancer.
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From page 178... ...
We have included studies of both mass-screening and case-finding programs to detect and treat melanoma and nonmelanoma skin cancer in the general population. In mass-screening programs, self-selected individuals respond to an invitation to undergo a total-body skin examination.
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Effectiveness of Early Treatment Arrow 4a Does treatment of non-melanoma skin cancer found by screening reduce morbidity and mortality? Arrow 4b Does treatment of malignant melanoma found by screening reduce morbidity and mortality?
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We examined the consequences of screening on detection of squamous cell carcinoma, basal cell carcinoma, and malignant melanoma (Arrow l b)
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From page 182... ...
; advertising targeted at high-risk groups or not targeted; reported risk factors of participants; and procedure for referring patients found to have a positive screen. We also abstracted the number and probability of the following events from each study: referrals for skin examination; compliance with referral; suspected basal cell cancers, squamous cell cancers, actinic keratoses, and melanoma; confirmed melanoma and melanoma in situ; negative screening examinations; biopsies performed; the number with confirmed melanoma and number with suspicious melanoma; and the number with confirmed melanoma and number of all
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From page 183... ...
Specificity was defined as the proportion of people who did not have skin cancer who had no suspicious lesions detected during the skin exam. The positive predictive value (PV+)
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From page 184... ...
In four of the studies, skin examination was considered positive if the lesion was suspicious of any skin cancer.3~38 In these studies, from 4.2 to 28.4 percent of subjects had suspicious lesions, and from 1 percent to 6 percent proved to have skin cancer. Basal cell cancer accounted for 74-93 percent of the confirmed skin cancer cases; melanoma, 7-27 percent, and squamous cell cancer, 0 4 percent of the skin cancer cases.
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From page 185... ...
Clinical suspicion was classified as "suspected melanoma" or "rule-out melanoma." Only 0.3 percent (n = 763) of the participants had a clinical diagnosis of suspected melanoma at the skin examination.
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The overall probability of cancer was calculated as the total number of cancers diagnosed divided by number of patients screened. For the first group of studies, all skin cancers are included in the numerator.
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APPENDIX B 187 Positive Suspicious BCC/ MM/ SCC/ Predictive Lesions Skin Skin Skin Value - Probability Cancer Cancer Cancer Biopsy Likelihood n % of Cancer (%)
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Overall sensitivity of the initial examination was 0.940 and specificity was 0.975. For a patient with a negative initial skin examination, the probability of having no skin cancer on follow-up was 0.998.
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From page 189... ...
.43 Four skin cancer specialists and 63 randomly selected general practitioners in Australia performed total-body skin examinations on 109 selected patients, 43 of whom had suspicious pigmented lesions diagnosed previously by a skin specialist. The sensitivity of total-body skin examination for detecting suspicious lesions was 0.72 for the GPs, versus 0.97 for the four skin cancer specialists.
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From page 190... ...
, and white race are the strongest risk factors for nonmelanoma skin cancer. Among whites who have no prior history of skin cancer or AK, sun exposure is the most important risk factor for nonmelanoma skin cancer.
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From page 191... ...
compared to those without sunburn history. Since the meta-analysis was published, an analysis of body site distribution among incident melanoma cases in British Columbia found that intermittent sun exposure was a risk factor for melanoma in individuals less than 50 years of age.56 A recent casecontrol study also supported the hypothesis that intermittent ultraviolet exposure is a risk factor for melanoma in younger individuals who are susceptible to burning.57 Reliability of Measures of Risk To be useful as practical tools for classifying patients into risk groups, risk factors must be reliably assessed by patients or physicians.
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From page 192... ...
In fact, no longitudinal studies of the use of a risk assessment tool in primary care practice have been reported. Although it was not done in a primary care setting, a large, prospective study validated the use of an initial count of atypical moles in predicting the incidence of melanoma over five years.63 In that study, 3,889 employees a the Lawrence Livermore National Laboratory had total-body skin examinations performed by a dermatology fellow specializing in melanoma.
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From page 193... ...
Most studies found from 2 to 10 suspected nonmelanoma skin cancers per 100 screened. In some populations, the rate of suspected basal or squamous cell carcinoma was much lower (4 per 10,000 in a Japanese study67)
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From page 194... ...
Not specified 0.1 Pt's PCP, no re- 0.2 mincer 42% came because of a "worrying mark," 25% fair skin, 53% h/o severe sunburn, 22% fair or red hair, 8% personal h/o so, 20% fam ily h/o sc Not targeted Pt's PCP or derrna tologist, no re rninder de Rooij, 1995 2,463 volunteers, Lesion specific Not targeted Pt's PCP, no re hospital, Nether- TSE winder lands; 53% >50 y/o de Rooij, 1997 4,146 volunteers, Lesion specific Targeted high risk Pt's PCP, no re- 0.-12 hospital, Nether- TSE rninder lands, 34% >50 y/o Katris, 1996 3,379 volunteers, TSE Targeted high risk Not specified hospital and corurnunity, Aus tralia; 35% 2 50 y/o, 16% 2 60y/o Katris, 1998 256 volunteers, TSE, nurses, and Target high risk Not specified hospital and plastic sur cornmunity, Aus- geons tralia Rivers, 1995 1,681 volunteers, TSEpartialskin Beachgoers;33% Pt'sPCP cornrnunity, Can- exam lesion had 2 or more ada; 16% specific, der- risk factors 2 65 y/o rnatologists (blond or red hair, blue or green eyes, pro pensity to sun burn)
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From page 195... ...
APPENDIX B 195 Results (p) MM Confirmed MM Biopsy Biopsy all Suspected Confirmed Melanoma in Suspected Suspected Negative Suspected Suspicious MM MM Situ BCC/SCC AK Screen Biopsy MM only Lesions 0.08 0.002 0.002 0.21 0.42 0.21 0.15 0.04 0.004 0.57 0.18 0.02 0.003 0.003 0.001 0.02 0.9 0.03 0.02 0.001 0.001 0.08 0.01 0.003 0.001 0.04 0.06 0.02 0.001 0.002 0.02 0.02 0.02 0.08 0.038 0.13 0.83 0.05 Surgeon: Nurse:.03 Surgeon: .10 .70 Nurse:.07 Nurse: .60 0.005 0.11 0.08 0.17 0.03 0.08 Continued
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From page 196... ...
Pt's PCP, no 2) 53 volunteers, tologists reminder hospital, US; mean age 35.4 Population Based Screening Harvey, 1995, 560 random popula- Partial skin exam, NA Pt's PCP, reminder 0.02 1996 tion sample, dermatologists community, UK; 1 00% 2 60 y/o Ichihashi, 1995 4,736 consecutive Partialskin exam, NA Study dermatologist, attendees at re- dermatologists no reminder gional health exam, Japan Tornberg, 1996 1,654 random Sam- Not specified, NA Study dermatologist, 0.05 pie, hospital, nurses, der- noreminder Sweden; 100% matologist, on 40-54 y/o cologist Bergenmar, 1997 501 random sample, NA NA hospital, Sweden; 100% 4~54 y/o Casefinding Ruskiewicz 1998 1,000 consecutive patients, optom etrist office, US; mean age 66.3 (range 35-96)
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From page 197... ...
APPENDIX B 197 Results (p) MM Confinned MM Biopsy Biopsy all Suspected Confirmed Melanoma in Suspected Suspected Negative Suspected Suspicious MM MM Situ BCC/SCC AK Screen Biopsy MM only Lesions 1)
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From page 198... ...
Other Herd, 1995 421 patients with suspected MM, specialty clinic, UK Marghoob, 1995 290 patients with BCC or SCC, dermatology prac tice, US Veirod, 1997 TSE, dermatologists NA Study dermatologist TSE (melanoma All had BCC Study dermatologist only) , derma- and/or SCC tologists Van der Spek- Pathology study of Keijser, 1997 all MM diagnosed from 1980 tol992 after regional pre ventive skin can cer campaign, Netherlands, 95% Caucasians Follow-up study of 50,759 partici pants in health screening from 1977-83, Norway, 16-56 y/o NA NA NA NA NA NA NOTE: AK = actinic keratoses; BCC = basal cell carcinoma; d = dermatologist; MM = malignant melanoma, p = primary care provider; PCP = primary care physician; SCC = squamous cell carcinoma; and TSE = total skin examination.
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From page 199... ...
199 USED O S_ced Coned Con0_d H~ ~ Sit Sim BC^CC ~H Betsy S_ced Nerve Seduced Men Betsy HM only Biopsy a11 S-icio~ lesion 0.036 0.22 0.034 0.~2 0.15
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From page 201... ...
The other, a population-based study in Sweden,77 had no confirmed melanomas of 152 suspected melanomas in 1,654 people screened. Eight studies in Table B-2 reported the number of histologically confirmed nonmelanoma skin cancers.
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From page 202... ...
For the 1,356 patients who went on for a total-body skin examination, no malignant melanomas and three basal cell carcinomas were identified. This finding raises doubts about the benefits of conducting total-body skin examinations on everyone rather than lesion-specific examinations.
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From page 203... ...
In a follow-up study to the American Academy of De~n~atology's Melanoma/Skin Cancer Screening Programs (see reference to Koh, 1996, in Table B-1) , 1,049 participants who had skin lesions were surveyed about their skin health behaviors two months after undergoing a totalbody skin examination.
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From page 204... ...
Well-done, frequently cited observational studies of the relationship between early detection and mortality have been done,92 but in such studies the effect of promoting primary prevention and self-examination cannot be distinguished from that of routine screening in patients seeing the physician for unrelated reasons.86 The lack of data reflects the lack of population-based programs that focus on routine total-body skin examination by a physician. The absence of randomized trials is also not surprising since melanoma is relatively rare in the general population.
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From page 205... ...
Basic information, such as the proportion of Medicare patients with nonmelanoma skin cancer who suffer disfigurement or death, is lacking. If we assume that 20 percent of squamous cell cancers in the elderly are either lethal or disfiguring, this assumes a prevalence of 0.025 for men and women combined and that screening would reduce this by half, about - 400 patients would have to be screened to prevent one lethal or disfiguring case.
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From page 206... ...
The investigators performed two multivariate analyses: one for primary prevention and one for secondary prevention. In the first analysis, after adjustment for sun exposure, skin color, the number of nevi, and other risk factors, skin self-examination was negatively associated with incidence of melanoma (OR 0.66; CI 0.44 0.994.
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From page 207... ...
In Australia, public information campaigns have promoted sun protection behaviors and early detection for more than 15 years. Melanoma mortality, which had increased for decades, reached a plateau in 1985 and, in recent years, has fallen slightly.93 It is thought that this trend is related to skin health promotion activities, including primary prevention and self-examination, but because it is not a prominent feature of these campaigns, it is not possible to determine what role, if any, screening by physicians has played.
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From page 208... ...
and have remained higher than before the program began. In contrast to these health promotion efforts, mass-screening programs cannot be evaluated using population-based registries.
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From page 209... ...
Cost-Effectiveness Studies of Screening for Skin Cancer A cost-effectiveness analysis of screening for malignant melanoma is currently in press.l04 The analysis found that the average projected discounted life expectancy was 15.0963 without screening versus 15.0975 with screening. This difference is equivalent to an increase of about nine hours per person screened or 337 days for each person with melanoma.
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From page 210... ...
Similarly, the model assumed that invasive cancers would decrease from 70.3 to 58.1 percent and melanomas thicker than 1.5 mm would decrease from 20.1 to 12.6 percent of invasive melanomas. These assumptions are based on comparison of crosssectional data on the stages of melanoma in individuals who attended the American Academy of Dermatology's mass screening programs with data on usual care from the SEER registry.
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From page 211... ...
APPENDIX B 211 elderly is particularly important, because there is little evidence from empirical studies that lethal tumors in this group are detectable when they are still in a curable stage. Appendix B continues on page 212
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212 v v, so |
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213 to Cal ._,— _ Cal ~ ~9- Us st o.
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Exp sensitivity and specificity · predictive value of tests · ROC curve 10.
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From page 216... ...
Increase in incidence rates of basal cell and squamous cell skin cancer in New Hampshire, USA. New Hampshire Skin Cancer Study Group.
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Risk of squamous cell carcinoma and methoxsalen (psoralen) and W-A radiation (PUVA)
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From page 218... ...
McLean DI, et al. Trends in basal cell carcinoma, squamous cell carcinoma, and melanoma of the skin from 1973 through 1987.
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From page 219... ...
Body site distribution of cutaneous malignant melanoma in relationship to patterns of sun exposure. Int J Cancer 1998; 78:276-280.
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From page 220... ...
Salopek TG, Kopf AW, Bart RS, Rigel DS. Basal cell and squamous cell carcinomas are important risk factors for cutaneous malignant melanoma.
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From page 221... ...
et al. Cancer Research Campaign health education programme to promote the early detection of cutaneous malignant melanoma.
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