Topical chemotherapy with 5-fluorouracil. A review

A randomized paired comparison of photodynamic therapy and topical 5-fluorouracil in the treatment of actinic keratoses

BACKGROUND

Photodynamic therapy (PDT) has not been compared with topical 5-fluorouracil (5-FU) in the treatment of epidermal dysplasia.

OBJECTIVE

The purpose of this study was to assess the efficacy and tolerability of these two treatment modalities in 17 patients with actinic keratoses on the backs of the hands.

METHODS

Each patient's right and left hands were randomized to receive either a 3-week course of topical 5-FU applied twice per day or PDT using topical 5-aminolevulinic acid (5-ALA) and then, after 4 hours, irradiation with an incoherent light source consisting of a 1200 W metal halogen lamp emitting red light (580 to 740 nm). Each hand randomized for PDT received 150 J/cm(2). The observed median fluence rate was 86 mW/cm(2) (interquartile range, 53 to 100 mW/cm(2)). All patients were reviewed at 1, 4, and 24 weeks after starting treatment.

RESULTS

Fourteen of 17 patients (82%) completed the study. The mean lesional area treated with topical 5-FU decreased from 1390 mm(2) (standard deviation [SD], 1130) to 297 mm(2) (SD, 209). This represents a mean reduction in lesional area of 70% (confidence interval [CI], 61%-80%). The mean lesional area treated with topical PDT decreased from 1322 mm(2) (SD, 1280) to 291 mm(2) (SD, 274), representing a mean reduction in lesional area of 73% (CI, 61%-84%). The reduction in lesional area elicited by the two treatment methods was similar (CI, -25% to 17%). There was no statistically significant difference between the treatment methods in overall symptom scores for pain and redness.

CONCLUSION

One treatment with PDT using topical 5-ALA appears to be as effective and well tolerated as 3 weeks of twice-daily topical 5-FU, a cheap and widely available alternative.

Guidelines for the management of basal cell carcinoma. British Association of Dermatologists

These guidelines on the management of basal cell carcinoma have been prepared for dermatologists on behalf of the British Association of Dermatologists. They present evidence-based guidance for treatment, with identification of the strength of evidence available at the time of preparation of the guidelines, and a brief overview of epidemiological aspects, diagnosis and investigation.

Recalcitrant hand and foot warts successfully treated with photodynamic therapy with topical 5-aminolaevulinic acid: a pilot study

The purpose of this pilot study was to determine if photodynamic therapy with topical application of 5-aminolaevulinic acid followed by irradiation with incoherent filtered and unfiltered light (ALA-PDT) is an effective therapy for recalcitrant hand and foot warts. In 30 patients with recalcitrant warts, 49 regions with a total of 250 warts were randomized to one of the following five treatments: (i) ALA-PDT with white light applied three times within 10 days (W3); (ii) ALA-PDT with white light applied once (W1); (iii) ALA-PDT with red light applied three times within 10 days (R3); (iv) ALA-PDT with blue light applied three times within 10 days (B3), and (v) cryotherapy applied up to four times within 2 months (CRYO). The ALA-PDT treatment modality was repeated in case of partially responding warts. Significantly more warts were completely healed after W3 and W1 than after R3, B3 and CRYO (P < 0.01): 73% of the warts treated with W3 were completely healed, 71% after W1, 42% after R3, 23% after B3 and 20% after CRYO. No scars were observed in the ALA-PDT treated areas and patients treated for foot warts were all able to walk after the treatment. No recurrences in completely responding ALA-PDT treated warts were observed after 12 months of follow-up. In conclusion, photodynamic therapy with topical 5-aminolaevulinic acid followed by irradiation with white light is a promising treatment for recalcitrant hand and foot warts.

Mucocutaneous reactions to chemotherapy

Chemotherapeutic agents are a widely used treatment modality. Side effects range from common to unusual and may be confused with other cutaneous sequelae of oncologic treatment. The goal of this communication is to elaborate on previous descriptions of the cutaneous manifestations of chemotherapeutic treatment and to discuss more recent findings.

LEARNING OBJECTIVE

At the conclusion of this learning activity, participants should be able to generate a differential diagnosis of possible etiologies for varying patterns of cutaneous involvement in patients receiving chemotherapy and identify the various cutaneous side effects of chemotherapeutic treatment. In addition, they should be able to distinguish life-threatening side effects that require immediate management from more benign manifestations of chemotherapeutic treatment.

Skin cancer of the head and neck

The incidence of skin cancers is increasing at a rate greater than any other cancer occurring in humans. In this era of managed care, patients with a suspicious skin lesion may first present to their primary care physician for evaluation. Therefore, it is important for the primary care physician to be able to distinguish between benign and malignant pigmented lesions, to know how to evaluate such a patient, and to appreciate the importance of appropriate interdisciplinary management of these patients.

Intralesional and topical chemotherapy and immunotherapy

Surgery is the mainstay of treatment for equine tumors. Conservative treatment approaches which preserve function and appearance are increasingly used in clinical practice. This article covers the principles and applications of two conservative treatment modalities including local chemotherapy and immunotherapy. The therapeutic benefit of local chemotherapy is based on the direct drug delivery to tumor tissue, i.e., topical and intratumoral administration of cytotoxic agents in slow release formulation. This treatment modality is very effective for cutaneous tumors and does not result in any permanent damage to normal tissue. Immunotherapy produces antitumor effects primarily through the action of natural host defense mechanisms against tumor cells. Although the use of immunotherapy is still under investigation there are many examples of its successful application to treatment of selected equine tumors.

Medical oncology in the management of head and neck cancers

General approaches and therapeutic goals of medical oncology for head and neck cancer are presented. The effectiveness of chemotherapy for the treatment of different stages of head and neck cancer in specific anatomic sites is discussed, as well as complications associated with chemotherapy, and approaches to the prevention and management of these stages. Systemic side effects that may occur with specific therapeutic agents are presented in a tabular format. Future directions and evolving approaches to head and neck cancer therapy are summarized.

Advances in antiviral therapy in dermatology

For years, investigators have sought to control viral transmission and to find appropriate treatment for people who have viral infections. Exposure control (e.g. vaccines, sanitation, vector control, blood testing, condoms/abstinence, and education) has been extremely important in management of viral spread. Several antiviral agents have received approval from the United States Food and Drug Administration over the past few years. There continues to be extensive research on new antiviral agents as well as new vaccines to control viral disease and spread. Most viral diseases continue to be treated symptomatically; however, the discovery of new and improved antiviral agents has added great power to our ability to treat certain hard-to-control viruses that plague patients.

Intratumoral chemotherapy with fluorouracil/epinephrine injectable gel: a nonsurgical treatment of cutaneous squamous cell carcinoma

BACKGROUND

We attempted to originate a nonsurgical treatment alternative for cutaneous squamous cell carcinoma (SCC), and we evaluated intratumoral modified-release chemotherapy with fluorouracil/epinephrine injectable gel (5-FU/epi gel).

OBJECTIVE

To assess the safety and efficacy, we conducted an open-label pilot study of 5-FU/epi gel in 25 patients with biopsy-proven SCC lesions on the face, head, neck, trunk, arms, and hands.

METHODS

Each tumor site was injected intradermally with up to 1.0 ml of 5-FU/epi gel. One SCC per patient was treated weekly for up to 6 weeks, then observed for 4 months at which time the tumor site and margins were excised for histologic examination.

RESULTS

Overall, 96% (22 of 23) of evaluable treated tumors had histologically confirmed complete tumor clearing. No clinically significant systemic reactions or unexplained treatment-related adverse medical events occurred. The evaluations of the cosmetic appearance of the treated sites, judged subjectively by clinicians and patients, were mostly good to excellent and generally in close agreement.

CONCLUSION

Treatment of superficial SCC with 5-FU/epi injectable gel results in a high rate of histologically confirmed complete tumor responses and may provide a nonsurgical treatment alternative in selected patients.

Does intermittent "pulse" topical 5-fluorouracil therapy allow destruction of actinic keratoses without significant inflammation?

BACKGROUND

Topical 5-fluorouracil (5-FU) is effective in removing actinic keratoses but causes unsightly and painful erosions. Intermittent "pulse" 5-FU therapy has been described as being an effective and comfortable technique for destroying actinic keratoses.

OBJECTIVE

The purpose of this study was to determine the efficacy and cutaneous side effects of intermittent 5-FU therapy.

METHODS

Efficacy of treatment was evaluated by three experienced dermatologists separately comparing randomly arranged before and after photographs. Degree of skin reaction was graded from photographs taken during treatment.

RESULTS

Of 13 patients treated with intermittent 5-FU, two had an excellent result, three a good result, but eight failed to show discernible improvement. Efficacy was linked to the degree of skin irritation.

CONCLUSION

Pulse 5-FU failed to clear actinic keratoses in most patients. Intermittent 5-FU treatment does not dissociate its therapeutic efficacy from its undesirable erosive effects. Pulse therapy is a less intensive way of employing 5-FU and may be of value in patients unwilling to accept the erosions and discomfort that accompany the traditional course of daily 5-FU applications.

Nonsurgical treatment of basal cell carcinomas with intralesional 5-fluorouracil/epinephrine injectable gel

BACKGROUND

To develop a nonsurgical treatment alternative for basal cell carcinomas (BCCs), we evaluated intralesional sustained-release chemotherapy with 5-fluorouracil/epinephrine injectable gel (5-FU/epi gel).

OBJECTIVE

To optimize the dose and treatment schedule, we compared the safety, tolerance, and efficacy of six treatment regimens of 5-FU/epi gel in patients with BCCs.

METHODS

Two doses and four treatment schedules of 5-FU/epi gel were compared in an open-label, randomized study of 122 patients with biopsy-proven BCCs. One BCC per patient was treated for up to 4 to 6 weeks, then observed for 3 months at which time the tumor site was completely excised for histologic examination.

RESULTS

Overall, 91% of evaluable treated tumors (106 of 116) in all regimens had histologically confirmed complete tumor resolution. No clinically significant treatment-related systemic adverse events occurred. The best response rate, tolerance, and patient compliance with assigned dose were in patients receiving 0.5 ml of 5-FU/epi gel three times a week for 2 weeks. The complete response rate based on histologic assessment in this group was 100%.

CONCLUSION

Results demonstrate that treatment of BCC with 5-FU/epi gel is both safe and effective, may result in histologically confirmed complete response rates comparable to surgery, and provides a nonsurgical treatment alternative in selected patients.

Topical 5-fluorouracil in the treatment of Darier's disease

Two patients suffering from therapy-resistant Darier's disease were treated with topical 5-fluorouracil (5-FU). The drug was applied in a concentration of 1% in a cream base, once daily, in left-right comparison with either 7.5% salicylic acid in petrolatum or 0.05% vitamin A acid cream. Both patients were on long-term treatment with oral retinoids. After 1 week of treatment, a considerable improvement was already apparent on the 5-FU-treated side, in comparison with the salicylic acid- and vitamin A acid-treated sides. Subsequent treatment of all skin lesions with 5-FU for a further 2 weeks resulted in complete clearance of the lesions. Remission periods were of 2-6 months duration. There were no significant adverse effects of treatment. Haematological parameters remained unchanged during the therapy. Topical 5-FU is a safe and useful addition to currently available treatments for Darier's disease.

Topical 5-fluorouracil in treating epithelial neoplasia of the conjunctiva and cornea

PURPOSES

To evaluate the efficacy of topical 5-fluorouracil (5-FU) in treating conjunctival and corneal epithelial neoplasia.

METHODS

Three patients underwent surgical excision of bulky disease followed by topical 1% 5-FU in artificial tear base for 2 to 3 weeks or until epithelial separation occurred. An additional three patients underwent treatment with topical 1% 5-FU alone.

RESULTS

Minimum follow-up was 6 months. In one patient with conjunctival in situ carcinoma and no detectable normal conjunctiva, who had normal findings on conjunctival histologic examination after application of topical 5-FU, a focus of invasive disease requiring orbital exenteration. One patient had a favorable response to 5-FU therapy but required a repeat excision for control of bulky disease. Four patients have remained disease-free for 10, 13, 18, and 30 months after topical 5-FU therapy.

CONCLUSION

With its potential selective toxicity on dysplastic epithelium, topical 5-FU shows promise as an adjunctive treatment for managing conjunctival and corneal epithelial neoplasia.

Topical 5-fluorouracil ointment for senile comedones: a case report

The usefulness of topical vitamin A acid for senile comedones was reported by Kligman et al. in 1971 (1). It is, however, not available in Japan. We treated senile comedones with topical 5-fluorouracil ointment and found that it was very effective.

The role of dermabrasion and chemical peels in the treatment of patients with xeroderma pigmentosum

We describe our experience with two patients with xeroderma pigmentosum who underwent periodic trichloroacetic acid chemical peels. One also received a full-face dermabrasion. The effect of chemical peeling was more transient than dermabrasion but was associated with less morbidity. Both chemical peeling and dermabrasion provided a prophylactic effect against the development of skin malignancies; the latter had a more pronounced effect.

Short-term intensive 5-fluorouracil treatment of actinic keratoses

BACKGROUND

5-Fluorouracil therapy is an efficacious treatment for actinic keratoses. However, the prolonged courses of therapy traditionally prescribed are unpleasant, uncomfortable, and can lead to noncompliance.

OBJECTIVE

To treat patients with shorter courses of 5-fluorouracil therapy.

METHODS

5-Fluorouracil cream or solution is applied four times daily for periods varying between 7 and 21 days, depending upon the body location.

RESULTS

The same brisk inflammatory reaction and clearing of the majority of actinic keratoses associated with longer courses of application twice daily is realized.

CONCLUSION

5-Fluorouracil can be applied four times daily for shorter periods of time, resulting in clearing of actinic keratoses and patient acceptability.

Clinical evaluation of topical isotretinoin in the treatment of actinic keratoses

BACKGROUND

Retinoids have been shown to improve the manifestations of skin photodamage, including actinic keratoses.

OBJECTIVE

The efficacy and tolerability of isotretinoin 0.1% cream in the treatment of actinic keratoses were evaluated in a randomized, double-blind, placebo-controlled, parallel-group study.

METHODS

One hundred patients were randomly assigned to treatment with 0.1% cream or vehicle twice daily for 24 weeks to the face, the scalp, and the upper extremities. Patients were assessed every 4 weeks by the investigators, who counted and recorded the number of lesions in each treatment area. The 93 patients who had at least one postbaseline assessment were included for efficacy analysis. Local tolerability was evaluated at each study visit.

RESULTS

On the face, the reduction in number of actinic keratoses (mean +/- SEM) at the end of treatment was greater for patients treated with isotretinoin (3.9 +/- 0.6, i.e., 66% of patients with a reduction > 30%) than with placebo (1.7 +/- 0.5, i.e., 45% of patients with a reduction > 30%); this difference was statistically significant (p = 0.001). No significant drug effect was seen for lesions on the scalp or upper extremities. Mild to moderate local reactions with isotretinoin abated with reduced treatment frequency.

CONCLUSION

Our results suggest that isotretinoin 0.1% cream cannot compete with more rapid treatments of actinic keratoses. However, its effect on facial lesions may be beneficial during long-term treatment of associated sun-damaged skin.

Squamous cell carcinoma of the skin. Will heightened awareness of risk factors slow its increase?

Although squamous cell carcinoma of the skin is still less common than basal cell carcinoma, its incidence is increasing at an alarming rate. Cumulative sun exposure is a major risk factor, and deterioration of the ozone layer combined with life-style choices that promote time in the sun may account for part of the increased incidence. Other risk factors for squamous cell carcinoma include exposure to ionizing radiation, arsenic, or industrial chemicals; viral infection; preexisting burns and scars; and immunosuppression. Actinic keratosis is considered a precancerous lesion that should be watched closely. Treatment methods for squamous cell carcinoma vary depending on the size and location of the lesion. Knowledge of high-risk locations and appropriate treatment choices ensures proper care and decreases the likelihood of metastasis.

Pulsed dye laser treatment of recalcitrant verrucae: a preliminary report

Patients with recalcitrant warts on the fingers and hands, periungual, and other parts of the body including verrucae plana and plantar surfaces were treated using the pulsed dye laser at 585 nm, 450 usec, and a spotsize of 5 mm diameter. Of the 39 patients treated, 28 (72%) were cleared of their warts after an average of 1.68 treatments at fluences of 6.25-7.5 J/cm2. Seven (18%) patients had a reduction of between 80-95% of their warts after 1.3 treatments, and verrucae reduced by 50% in four of the 39 patients after one treatment. The average follow-up period of the 28 cases cleared of their warts has been 5 months. Of this group, those with periungual warts have been followed for up to 6.4 months, compared to 4.8 months for those with warts on other parts of their body, 4.0 months for those with finger and hand warts, and 2.0 months for plantar warts. Only one of the 28 patients has had a recurrence after 3 months of clearance.

Long-term management of basal cell nevus syndrome with topical tretinoin and 5-fluorouracil

The case of a child with basal cell nevus syndrome whose condition was successfully managed for 10 years with a combination of topical 5-fluorouracil and tretinoin is reported. The concurrent use of these two agents prevented the development of new tumors, inhibited the growth of existing tumors, and caused the regression of superficially invasive basal cell carcinomas.

The effect of intralesional 5-fluorouracil therapeutic implant (MPI 5003) for treatment of basal cell carcinoma

BACKGROUND

Basal cell carcinomas (BCCs) are usually treated with ablative procedures. A nonsurgical treatment alternative would be of value in selected patients.

OBJECTIVE

We evaluated the safety and efficacy of a new preparation for intralesional sustained-release chemotherapy with MPI 5003, 5-Fluorouracil Therapeutic Implant, for treatment of BCCs.

METHODS

Two doses of intralesional MPI 5003 (0.25 and 0.5 ml) were compared in a double-blind study of 20 patients with biopsy-proven BCC. One BCC per patient was treated weekly for up to 6 weeks and followed up monthly for 3 months until excisional biopsy for histologic examination. Before excision the cosmetic appearance of the test site was graded.

RESULTS

Eighty percent of 10 BCCs treated with 0.5 ml of MPI 5003 had histologically confirmed cures as compared with 60% of 10 tumors treated with the lower dose (0.25 ml). Cosmetic assessments before excision were typically good to excellent. No systemic side effects occurred.

CONCLUSION

Results indicate the potential of MPI 5003 for targeted local chemotherapy for BCC.

Dermabrasion: therapy and prophylaxis of the photoaged face

BACKGROUND

For many years dermabrasion has been used for the treatment of photoaged facial skin. However, there is a paucity of correlative studies that document the beneficial histopathologic effects of dermabrasion with clinical changes. Moreover, long-term follow-up and comparative studies that document these therapeutic results are lacking.

OBJECTIVE

Our purpose was to study patients with photoaged facial skin by comparing the preoperative and postoperative clinical and histopathologic changes that occur as a result of surgical dermabrasion of aged and photodamaged facial skin.

METHODS

Twelve patients 40 years of age and older with significant photoaging and dermatoheliosis were treated with full-face dermabrasion. Predermabrasion biopsy specimens were compared with matched postdermabrasion biopsy specimens taken at various time intervals from 6 months to 8 years after dermabrasion.

RESULTS

Microscopic normalization of the actinically damaged epidermis and papillary dermis was manifested clinically by the replacement of dermatoheliosis with supple, smooth-textured facial skin that remained clinically evident well beyond 8 years after dermabrasion. In addition, the necessity for the continued treatment of premalignant and malignant lesions was virtually eliminated during the 8-year postdermabrasion period.

CONCLUSION

Not only is dermabrasion a beneficial therapeutic option for aged and photo-damaged skin, but it also is a valid means of prophylaxis against neoplastic changes.

Weekly pulse dosing: effective and comfortable topical 5-fluorouracil treatment of multiple facial actinic keratoses

Ten patients completed a weekly pulse dosing regimen for topical 5-fluorouracil therapy for multiple facial actinic keratoses. The method cleared an average of 98% of the lesions, without the severe irritation usually caused by the conventional, daily dosing regimen. Nine patients described the therapy as comfortable. Local irritation was limited to erythema. None of the patients suffered disruption in their social or business lives because of altered appearance. Patients had an average of 6.7 weeks of treatment and applied the medication 1 to 2 days per week; significant remissions were achieved. The longest available follow-up is with six patients who at 9 months remained 86% clear of lesions. This new method offers a significant advance in topical 5-fluorouracil therapy by reducing irritation to an acceptable level while maintaining efficacy.

A double-blind, vehicle-controlled study evaluating masoprocol cream in the treatment of actinic keratoses on the head and neck

This double-blind, vehicle-controlled, multicenter study evaluated the efficacy and safety of a new topical antineoplastic agent, masoprocol, in the treatment of actinic keratoses of the head and neck. Of the 113 patients who applied topical masoprocol twice a day for 14 to 28 days, there was a mean decrease in actinic keratoses from 15.0 to 5.4 and a median percent reduction from baseline actinic keratosis count of 71.4% at the 1-month follow-up visit. Comparable numbers for the vehicle-treated group were 13.4 to 11.1 actinic keratoses and 4.3% median percent reduction. Irritation, as manifested by erythema or flaking, occurred in 61.5% of topical masoprocol-treated patients versus 26.7% of those treated with vehicle and did not correlate with clinical response. Topical masoprocol appears to be useful in the treatment of actinic keratoses.

Topical treatment of multiple actinic keratoses of the face with arotinoid methyl sulfone (Ro 14-9706) cream versus tretinoin cream: a double-blind, comparative study

In a double-blind, randomized, within-patient comparative study, the efficacy and tolerability of Ro 14-9706 (an arotinoid methyl sulfone) in the treatment of actinic keratoses was compared with that of tretinoin (all-trans-retinoic acid). A total of 25 patients with more than three lesions on each side of the face completed the study. All patients applied each agent twice daily for 16 weeks as a 0.05% cream to opposite sides of the face. The number of actinic keratoses in each treatment area was counted before treatment and at weekly intervals. The mean percent decrease in the number of actinic keratoses was 37.8% for areas treated with Ro 14-9706 and 30.3% for areas treated with tretinoin. Each of these decreases was significantly different from baseline (p less than 0.01), but not from each other. Ro 14-9706 was better tolerated; local inflammation was slight or absent in most patients, whereas tretinoin caused severe erythema in 50% and severe scaling in 23% of patients.

Transdermal delivery of 5-fluorouracil through skin of hairless mice and humans in vitro: a comparison of the effect of formulations and a prodrug

A 2% commercial solution formulation of 5-fluorouracil (5-FU) was significantly better at delivering 5-FU than either a 1% or 5% solution. Among single component suspension formulations the highest transdermal delivery was obtained from the vehicle in which 5-FU was least soluble, isopropyl myristate (IPM), while changes in the total suspended concentration of 5-FU in propyleneglycol (PG) had no significant effect on transdermal delivery by those suspensions. A prodrug of 5-FU/IPM was significantly better at delivering 5-FU than any of the formulations. The trends in relative rates of delivery of 5-FU by the formulations and the prodrug were the same in skin of hairless mice and humans. The mouse skin was about ten times more permeable than the human skin. Second application studies to assess skin damage caused by the formulations also showed the same trend in skin of hairless mice and humans: all of the formulations caused some damage.

Mucocutaneous side effects of chemotherapy

Increasing numbers of chemotherapeutic agents are being used to treat patients with cancer. They have only a slight margin of safety between the tumoricidal and toxic doses. The skin is a frequent target for the side effects of these drugs, and the clinician should be alert to these manifestations so that needless diagnostic work up is avoid.

Dipyridamole potentiates the growth-inhibitory action of methotrexate and 5-fluorouracil in human keratinocytes in vitro

Human keratinocytes transport extracellular thymidine across the plasma membrane and incorporate it into DNA. Data presented here show that dipyridamole, a well-known inhibitor of facilitated diffusion of nucleosides, blocks the transport of thymidine into human keratinocytes in vitro. Dipyridamole (1.0 microM) inhibited the transport of 3H-thymidine (0.2 microM) into intracellular material by 75% and its subsequent salvage and incorporation into DNA by 48%. Dipyridamole (1 microM) did not affect the growth of keratinocytes in vitro but did potentiate the growth inhibition caused by methotrexate (MTX) or 5-fluorouracil (5-FU). The growth of keratinocytes exposed to 0.1 microM MTX for 8 d was inhibited by 32%. However, in combination with a noninhibitory concentration of dipyridamole (1 microM), this concentration of MTX (0.01 microM) inhibited the growth of keratinocytes by 93%. Thymidine in culture medium reversed the cytotoxicity of MTX. However, in the presence of dipyridamole, thymidine in the culture medium did not reverse the action of MTX. The synergistic interaction between MTX and dipyridamole was also observed with 5-FU and dipyridamole. 5-FU (0.5 microM) inhibited cell growth by 30% but in combination with dipyridamole (1 microM), inhibited cell growth by 86%. These data are consistent with the theory that inhibiting thymidine salvage by blocking transport of extracellular thymidine potentiates the growth inhibitory action of inhibitors of de novo pyrimidine biosynthesis in human keratinocytes. Combination chemotherapy, such as methotrexate plus dipyridamole, might be efficacious in the treatment of hyperproliferative diseases of the epidermis.

Management of oral squamous cell carcinoma in situ with topical 5-fluorouracil and laser surgery

Oral squamous cell carcinoma in situ has been described as a relatively rare lesion. However, difficult decisions with respect to clinical management of the lesion in this location parallel those reported for other mucosal sites, such as the cervix or the larynx. The lesion, though superficial, may extend over a large area of tissue, and attempts at irradication with surgery or radiation therapy may be associated with a great deal of morbidity. However, the risks in deferral of treatment while "watchfully waiting" may also be unacceptable. A method and rationale for management of oral squamous cell carcinoma in situ with the use of topical 5-fluorouracil and carbon dioxide laser are described in this article. A technique for using an intraoral prosthesis to potentiate drug delivery is also described. Though morbidity can be very significantly reduced, patient compliance is an important consideration for success with this protocol.

Scrotal dermatitis caused by 5-fluorouracil (Efudex)

Four patients are described who experienced an acute episode of eczematous dermatitis of the scrotum where 5-fluorouracil (Efudex) cream had inadvertently been applied in the course of treating warts and keratoses. The reaction was not allergic in origin but resulted from the unique absorptive capabilities of scrotal skin, which permitted entrance and local toxic effects of 5-fluorouracil.

Role of preoperative topical 5-fluorouracil in preparation for Mohs micrographic surgery of extramammary Paget's disease

The true extent of the skin affected in extramammary Paget's disease is frequently well beyond its clinical borders. A case of extramammary Paget's disease of the scrotum was treated with Mohs micrographic surgery. Prior to surgery, 5-fluorouracil was applied topically for 10 days. This resulted in a sharply delineated, erythematous patch of biopsy-proved extramammary Paget's disease well beyond the original clinical borders. This increased the visible area of disease by 60%. Mohs micrographic surgery detected microscopic extramammary Paget's disease approximately 1 cm beyond the erythematous borders. The location of disease farthest from the margins was in the direction toward which this erythema was most advanced when the application of 5-fluorouracil was discontinued. At the time of writing, 3.5 years after treatment, the patient was free of disease. Topical 5-fluorouracil may have a role as an adjunct to surgery by highlighting subclinical areas of extramammary Paget's disease. It may also be useful postoperatively to detect early disease recurrence.

Use of theoretical partition coefficients determined from solubility parameters to predict permeability coefficients for 5-fluorouracil

Values for experimental permeability coefficients of 5-fluorouracil (5-FU) in 7 single- and 4 two component vehicles were determined from flux measurements through hairless mouse skin in diffusion cells and from solubility data. Theoretical partition coefficients of 5-FU between vehicle and skin were determined from solubility parameters of drug, vehicle, and skin, and from this theoretical permeability coefficients were estimated. Comparison of theoretical with experimental values for the permeability coefficients showed a good correlation for vehicles with solubility parameters between 12-18 (cal/cm3)1/2. For vehicles or mixtures of vehicles with solubility parameters in the range of 8-12 (cal/cm3)1/2, increases in flux and permeability coefficients were seen compared with theoretical predictions, possibly due to the similarity in solubility parameters of the vehicles to that of skin (10 cal/cm3)1/2. There was an inverse relationship between 5-FU solubility in the vehicles and flux or permeability coefficient that corresponded approximately to the point where the solubility parameters of drug and vehicle were the same.

Topical application of 5-fluorouracil in premalignant lesions of cornea, conjunctiva and eyelid

Local application of 5-Fluorouracil was practised on 5 patients. In 3 patients with multiple premalignant oculo-cutaneous lesions, two of whom had also premalignant epibulbar lesions, local 5% 5-Fu cream and/or 1% 5-Fu eyedrops were applied. In 2 other patients who had only premalignant lesions on the cornea and conjunctiva, 1% 5-Fu eyedrops were used only. In animal experiments 1% 5-Fu was not found to cause any damage to normal corneal and conjunctival epithelium. The frequency of the applications and the duration of the treatment were dependent on the location and extent of the lesions. Except for easily treatable lesions, caused by the separation of the tumour epithelium, no complications of local 5-Fu treatment were seen. The visual acuity improved in all 4 patients in whom the cornea was affected. In these premalignant conditions the diagnosis and assessment of the therapy were based on exfoliative cytology and biopsies.

Large keratoacanthomas in difficult locations treated with intralesional 5-fluorouracil

Keratoacanthoma is a benign tumor; however, it may cause massive destruction of normal tissue during its rapid growth phase. Intralesional 5-fluorouracil (5-FU) has been shown to be an effective treatment for keratoacanthoma. We have successfully treated five patients with large keratoacanthomas in difficult locations. There have been no recurrences during follow-up periods ranging from 18 to 45 months. Intralesional 5-FU may be ineffective for keratoacanthomas that are not rapidly proliferating.

Dermabrasion of the scalp as a treatment for actinic damage

Dermabrasion of the scalp was safely and effectively performed on five patients as a treatment for actinic damage. This surgical modality can be an important part of the management of solar keratoses of the scalp in patients with alopecia.

Cutaneous side effects of cancer chemotherapy

Chemotherapeutic agents are used with increasing frequency to treat a wide variety of neoplastic and inflammatory disorders. These drugs may inadvertently affect the skin, mucous membranes, hair, and nails, producing many undesirable reactions including alopecia, stomatitis, hyperpigmentation, hypersensitivity reactions, and photosensitivity. Awareness of these relatively common complications may help physicians caring for patients on these medications.

Bowenoid papulosis of the genitalia associated with human papillomavirus DNA type 16 in an infant with atopic dermatitis

A case of bowenoid papulosis occurred in a 2-year-old male with atopic dermatitis. Clinical and histologic features of the lesions were typical, and human papillomavirus type 16 DNA was identified using high-stringency hybridization techniques. Although the lesions had been present for approximately one year prior to examination, they subsequently resolved spontaneously over six months. We postulate that our patient's susceptibility to human papillomavirus may have been related to his severe atopic tendency.