Support for Population- Based Skin Cancer Screenings

Most dermatologists agree that regular skin exams are an important tool in the detection and efficient management of skin cancers. Specialists have for quite some time championed regular skin exams as an effective strategy to identify early melanomas and other skin cancers, when, in theory, tumors are most likely to be localized and easily resected with low risk for local invasion or metastasis. Treatment of early tumors is associated with decreased morbidity and mortality.

There is widespread support for screenings as a form of primary prevention of skin cancers. Primary prevention consists of limiting exposure to sunlight and using sunscreens and seeking medical attention for a suspicious or changing nevus.

Less clear is the role for screening in secondary prevention. Secondary prevention consists of routinely performing a total skin examination for a segment of the population. Screening can be performed on whole populations or on subgroups of the population who are at higher risk for melanoma. Several organizations recommend routine screening solely for highrisk groups. These groups include those with excessive sun exposure, atypical moles, large numbers of acquired nevi, family history of melanoma or a personal history of nonmelanoma skin cancer, giant congenital nevi, and immunosuppression. Screening of the general population has not had similar endorsement, largely due to a lack of reliable data. The generally accepted methodology for demonstrating that a screening test is effective is to show that it is accurate and that early detection is beneficial to the patient. The US Preventive Services Task Force has found insufficient evidence to recommend for or against routine screening for melanoma by primary care physicians. Only the AAD, NIH Consensus Conference on Early Melanoma, and the American Cancer Society favor populationbased screening in addition to screening for high-risk groups. Up to this point, there has been no evidence to support populations based screening and most importantly, there have been no randomized controlled trials. A new study provides the first evidence in support of dermatology-based skin exams in the general population and show that screenings can lead to reduced mortality.¹

Signs of Benefit

Previous research has shown that skin exams identify skin cancers in their early stages that might otherwise go undetected. In a retrospective analytical case review of a dermatology practice in Florida, a majority (56.3 percent) of melanomas were found by the dermatologist and were not part of the presenting complaint. Dermatologist detection was again associated with thinner lesions.² Studies confirm that physician-detected melanomas are thinner than those detected by affected individuals or their spouses.³ While this particular study did not confirm whether all diagnosing physicians were indeed dermatologists, the nature of a retrospective chart review of a melanoma database suggest most were. Similarly, a study from the Johns Hopkins Melanoma Center shows that the median thickness of physician-detected melanomas was 0.23mm, versus 0.9m for patient-detected tumors. Again, the study did not specify the physicians' specialty, but presumably most were dermatologists. Also of interest in this study, just under one quarter of tumors (24 percent) were detected by physicians, compared to more than half (55 percent) by patients. This suggests a need for increased surveillance by physicians.

The evidence also supports dermatologists' enhanced ability to diagnose melanomas compared to other physicians. A retrospective cohort analysis of 218 patients diagnosed with melanoma in the mid-1990s found that initial melanomas detected by dermatologists were more likely to be 0.75mm or less in depth than those found by other physicians.⁴

These studies focus largely on screening patients presenting to a dermatology clinic—many of whom have concerns about suspicious lesions, known risks for skin cancer, or a personal history of skin cancer. But what about the general population? Clearly general screenings detect skin cancers. When “Melanoma Monday” launched in Belgium, the program led to identification of 25 melanomas and 59 suspected BCCs among 2,767 patients screened.⁵ Anecdotally, Melanoma Monday screenings in the US are credited with identifying multiple skin cancers, though reliable statistics are not available.

But to what extent do skin exams in the general population contribute to decreased morbidity and mortality? Screenings detect cancers, but can we quantify their benefit, and does the benefit justify their use? No large-scale studies had been conducted to quantify the benefits of dermatology screenings in the general population.

Further complicating matters, some publications have actually seemed to argue against screening in the general population. For example, in 2009 the US Preventive Services Task Force issued a recommendation on screening that was largely reported in the medical and lay press. The group concluded that “the current evidence is insufficient to assess the balance of benefits and harms of using a whole-body skin examination by a primary care clinician or patient skin self-examination for the early detection of cutaneous melanoma, basal cell cancer, or squamous cell skin cancer in the adult general population.”⁶ Importantly, this recommendation applies to primary care clinicians, not dermatologists, a point that may have been overlooked in some reports. Still, the recommendation shows that there is an assessment of value to be made regarding screenings.

The Latest Findings

The current data in support of large scale screenings come from the population-based SCREEN project (Skin Cancer Research to Provide Evidence for Effectiveness of Screening in Northern Germany) implemented in the German state of Schleswig-Holstein.1 Through the program, citizens (aged≥20 years) with statutory health insurance were eligible for a standardized whole-body examination during the 12-month study period, and of 1.88 million eligible citizens, 360,288 participated. The overall population-based participation rate was 19 percent. A wide range of practice-based physicians (dermatologists, general practitioners, gynecologists, internists, surgeons and urologists) were invited to participate in the project. To perform the screening, an eight-hour course was given to educate these physicians.

In total, 3,103 malignant skin tumors were found through the screenings. On the population level, invasive melanoma incidence increased by 34 percent during SCREEN. Five years after SCREEN, there was a substantial decrease in melanoma mortality. The observed rates of melanoma deaths for men were 0.79/100,000 for men and 0.66/100,000 for women, compared to the expected rates of 2.00/100,000 and 1.30/100,000, respectively.

Although not a randomized controlled trial, this analysis clearly shows a reduction both in the skin cancer burden and melanoma-associated mortality in relationship to a systematic screening program for the general population. These findings led to implementation of a national statutory skin cancer early detection program in Germany in 2008.

Conclusions

The recent German study is the first to demonstrate the value or skin cancer screenings in the general population by both dermatologists and other physicians educated to perform skin examinations. US dermatologists may be reassured of the benefit of skin exams for all their patients. Furthermore, those who participate in community screenings can be assured of the value of their service. Finally, educating all physicians on the importance of skin examinations serves all patients in good stead. Findings such as this may also lead to changes in policy so that patients will receive health insurance coverage for regular skin exams. It would be useful to see data that quantify the cost of regular exams and treatment of early lesions relative to the costs of delayed diagnosis. Preventive medicine is a key element of ongoing health reform initiatives. Skin cancer screenings ought to be part of that dialogue.

1. Breitbart EW, Waldmann A, Nolte S, et al. Systematic skin cancer screening in Northern Germany. J Am AcadDermatol. 2012 Feb;66(2):201-11.
2. Kantor J, Kantor DE. Routine dermatologist-performed full-body skinexamination and early melanoma detection. Arch Dermatol. 2009 Aug;145(8):873-6.
3. Schwartz JL, Wang TS, Hamilton TA, et al. Thin primarycutaneous melanomas: associated detection patterns, lesion characteristics, andpatient characteristics. Cancer. 2002 Oct 1;95(7):1562-8.
4. Francken AB, Shaw HM, Thompson JF. Detection of second primary cutaneous melanomas. Eur J Surg Oncol. 2008 May;34(5):587-92.
5. Vandaele MM, Richert B, Van der Endt JD, et al. Melanoma screening: results of the first one-day campaign in Belgium (‘melanoma Monday'). J Eur Acad Dermatol Venereol. 2000 Nov;14(6):470-2.
6. http://www.uspreventiveservicestaskforce.org/uspstf09/skincancer/skincanrs.htm