actinic keratoses (AKs) are, in fact, squamous cell carcinoma and should be treated with the Mohs technique. This approach raises thorny ethical issues.

Patients with actinic keratoses (AKs), as all Mohs surgeons know, have rough, keratotic, white, 1–2-mm papules and larger plaques that are typically found on the sun-exposed areas of the body, especially seen on the hands, arms, and faces of middle-aged individuals. These patients invariable have sustained a significant amount of sun damage and account for the second most common diagnosis given for seeking dermatologic care. There is clearly a wide array of AK treatment options that can be used to fit a patient’s needs [5].

The recognition of actinic keratoses is important because of their association with squamous cell carcinoma (SCC), an invasive cancer with the capacity to metastasize and result in significant morbidly and even mortality. With few exceptions, like thermal burn scars, chronic leg or decubitus ulcers, and smoking, the generally accepted theory is that AKs represent a precursor to squamous cell carcinomas resulting from chronic sun exposure.

The explanation given for treating AKs is that they represent precursors to SCCs [6]. Epidemiological data from the National Ambulatory Medical Care Survey (NAMCS) estimates that in 1993–94, there were 7.2 million office visits with the ICD-9 code diagnosis of AKs. The incidence of non-melanoma skin cancers (NMSCs) is strongly associated with age. If AKs are precursors to NMSC, then a similar age distribution should also exist for them as well. In fact, NAMCS data has shown that there were 6.3 million visits for NMSCs during that same time period. Similar results have also been shown in previously published studies. At least one high-profile article has been published in which the author makes the argument that AKs are the earliest form of SCC that can be identified and should be treated as such, not as a preventative measure. If they represent SCC, then a variety of techniques (perhaps including the Mohs technique) can be considered as treatment options.

If one takes the counterposition that AKs are only precursor lesions to SCCs, then some estimate must be made as to the rate of the progression from AK to NMSC. Otherwise, it would be logical to treat all AKs as soon as they are diagnosed in order to prevent the subsequent development of SCCs [7]. Estimates of the progression from AK to SCC have varied widely from a low of only 0.025% to as much as 16% per year.

Clinical experience has shown that some AKs do not evolve into cancer at all, or that evolution occurs so slowly that treatment can be delayed or postponed indefinitely, since some of these lesions may even disappear without treatment. What are the treatment options one might consider?

45.8.1.1 Invasive Techniques

Cryosurgery

Cryosurgery, using liquid nitrogen in a spray or contact technique with cotton tip applicators or solid metal probes, remains the most common form of treatment used today. Multiple lesions can be treated quickly, and the cure rate is high.

Curettage and Electrodessication

Other invasive techniques have also been used in the treatment of AKs. One of the oldest techniques, curettage and electrodessication, is used when the lesion is large, has indistinct margins, or there is concern about the depth of the growth.

Dermabrasion and Chemical Peels

When a multitude of AKs involve large areas of the face or scalp, cryosurgery or curettage and electrodessication are usually inappropriate treatment options. In these situations, dermabrasion or chemical peels using topically applied trichloroacetic acid (TCA) or phenol can be considered. It must be remembered that complications can be expected when dermabrasion or chemical peels are used to treat AKs on the thinner skin of the hands and where there are limited numbers of skin appendages, like hair follicles or eccrine sweat ducts, from which reepithelialization can occur.

Carbon Dioxide or Erbium:YAG Laser Ablation

Over the past 10 years, several short-pulsed lasers, like the carbon dioxide and erbium:YAG, have been successfully used for skin rejuvenation due to their limited collateral thermal effects. These same devices can simultaneously be used to remove AKs as well.

45.8.1.2 Non-invasive Techniques

Topical Chemotherapy

When patients have large numbers of AKs and do not want to undergo treatment with one of the invasive techniques, several different topical agents have shown to have beneficial results. The oldest technique consists of the topical application of a chemotherapeutic

agent, 5-fluorouracil (5-FU), for 4–6 weeks. This drug works by inhibiting thymidylate synthetase to deplete thymidine and reduce DNA synthesis by active proliferating cells. There can be a severe reaction to this agent with swelling, erythema, dryness, crusting, and burning pain that may cause some patients to become non-compliant and not complete the full course of therapy. However, when used as directed topical 5-FU can be very effective. Use of topical retinoic acid has also been shown to be effective in treating AKs, but typically requires long treatment schedules of many months duration. Due to its rejuvenation effects, many patients may tolerate this form of therapy better than a shorter course of treatment using 5-FU.

A newer form of topical chemotherapy that is well tolerated in the treatment of AKs consists of the application of one of the non-steroidal anti-inflammatory drugs, diclofenac. This drug selectively inhibits COX-II and after 3 months of therapy has reduced the number of AKs without significant side effects. Although less effective than 5-FU, it may provide a treatment alternative to patients who cannot tolerate the irritation of other treatments.

Photodynamic Therapy (PDT)

PDT can be used to treat AKs using topically applied delta-aminolevulinic acid (ALA) as the photosensitizer and a variety of non-laser lights for the activator. While the treatments were painful and resulted in crusting and erythema in some patients, it produced relatively high cure rates.

Topical Immune Response Modifier Therapy

A non-specific method to activate an enhanced local immune response has recently been developed to treat AKs. One of these agents, imiquimod, stimulates the production of interferons and natural killer cells that clear the AKs with less swelling, redness, and crusting than seen with topical 5-FU.

When selecting the proper form of treatment for AKs, the patient must play an important role in choosing what is right for their particular circumstances. The patient should always be allowed to make an informed decision as to what type of treatment they wish to receive. A younger patient working with the public may choose a procedure or therapeutic method that has little risk of scarring or hypopigmentation and the best chance for a good cosmetic outcome. A physically active patient may choose a technique that produces

the least restriction on their activities. An elderly patient may choose a form of treatment that would reduce the number of return visits to their physicians’ offices. All of this is as it should be, for that is the art of medicine – helping the patient to make the best decision as to their health care options. With all of these highly successful available methods, there would seem to be no ethical justification for the treatment of AKs with Mohs surgery.

45.8.2Non-Physician Performance of Mohs Surgery

Medicare Part B pays for services that are billed by physicians but are performed by non-physicians. These services often are called “incident to” services, or services provided under the “incident to” rule. “Incident to” services in theory may be vulnerable to overutilization and may place patients at risk of receiving treatment that does not meet professionally recognized standards of care. In a recent Officer of Inspector General (OIG) from Department of Health and Human Services analysis, a random selection of 250 “physician day” treatments were analyzed. Physicians were asked to submit relevant credentials for the non-physi- cian-provided services [8]. Part of the analysis looked at whether such non-physicians were qualified to render the particular services. In making these determinations, the nurse reviewers considered any relevant Medicare requirements, state laws and regulations, and the evaluating nurse’s own professional judgment as to whether the provided services generally fell within the standard competencies of the particular non-physician provider who rendered the services. In the evaluation, particular focus was placed on physicians who billed for more than 24 h worth of service in a day. It was determined that physicians performed about half of these services. Non-physicians performed the remaining half of the services in which physicians billed as “incident to” services. In the 3-month OIG evaluation period, Medicare allowed $105 million for approximately 934,000 services that physicians personally performed and approximately $85 million for 990,000 that non-physicians performed during this time period. Of note, non-physicians performed almost 2/3 of the invasive procedures that Medicare allowed the physicians. Of these procedures, Medicare allowed $12.6 million for approximately 210,000 services performed