Effect of Topical Fluorouracil Cream on Photodamage: Secondary Analysis of a Randomized Clinical Trial

Importance

Photoaging, which is premature skin aging caused by long-term UV exposure, is of aesthetic concern to many patients.

Objective

To investigate the effect of topical fluorouracil, 5%, cream on photoaging using validated photonumeric scales.

Design, Setting, and Participants

The Veterans Affairs Keratinocyte Carcinoma Chemoprevention Trial was a randomized clinical trial of 932 US veterans with a recent history of 2 or more keratinocyte carcinomas performed from September 30, 2011, through June 30, 2014, to assess the chemopreventive effects of a standard course of topical fluorouracil. Photographs were taken at baseline and at numerous time points for up to 4 years. In our secondary analysis, 2 independent dermatologists graded these photographs using 4 validated photonumeric scales. A total of 3042 photographs from 281 participants randomized to apply topical fluorouracil or placebo were evaluated at baseline, 6 months, 12 months, and 18 months using 4 photonumeric scales (Griffiths scale, Allergan forehead lines scale, melomental folds scale, and crow's feet scale). Data analysis was performed from November 1, 2016, to January 1, 2017.

Interventions

Participants were randomized to apply topical fluorouracil, 5%, cream or a vehicle control cream to the face and ears twice daily for 2 to 4 weeks for a total of 28 to 56 doses.

Main Outcomes and Measures

Effect of a standard course of fluorouracil on the extent of photodamage as measured using 4 photonumeric scales.

Results

The study population was predominantly male (274 [97.5%]) and white (281 [100%]), with a mean (SD) age of 71.5 (0.57) years. No statistically significant changes were found in photodamage between baseline and 6 months (Griffiths scale: χ2 = 0.01, P = .93; Allergan forehead lines scale: χ2 = 0.18, P = .67; melomental fold scale: χ2 = 0.03, P = .87; crow's feet scale: χ2 = 2.41, P = .12), 12 months (Griffiths scale: χ2 = 1.39, P = .24; Allergan forehead lines scale: χ2 = 0.64, P = .43; melomental fold scale: χ2 = 0.12, P = .73; crow's feet scale: χ2 = 1.07, P = .30), and 18 months (Griffiths scale: χ2 = 3.11, P = .08; Allergan forehead lines scale: χ2 = 0.89, P = .34; melomental fold scale: χ2 = 1.64, P = .20; crow's feet scale: χ2 = 0.46, P = .50).

Conclusions and Relevance

This study did not demonstrate improvement in photoaging with a standard course of topical fluorouracil, 5%, cream, a finding that may be attributable to a true lack of effect in photodamage or limitations of the photonumeric scales in capturing the effect. The development of photonumeric scales that include manifestations of photoaging other than rhytids, such as lentigines, hyperpigmentation, and telangiectasias, should be considered.

Trial Registration

clinicaltrials.gov Identifier: NCT00847912.

Current perspective on actinic keratosis: a review

Actinic keratoses (AKs) are common, with prevalence in the U.S.A. estimated at almost 40 million in 2004 and annual costs of > $1 billion (U.S.D.). However, there is no universally accepted definition of AK and thus it is difficult to identify reliably. AKs are lesions of epidermal keratinocytic dysplasia that result from chronic sun exposure and have the ability to progress to invasive squamous cell carcinoma (SCC), but clinicians disagree about whether AKs are premalignant lesions, superficial SCCin situ or epiphenomena of chronically sun-damaged skin. Yearly AK to SCC progression rates of 0·6% were reported in an elderly population with multiple prior keratinocyte carcinomas (KCs); and rates of spontaneous AK regression have been reported to be > 50%, but regressed lesions often reappear. As AKs have both cosmetic consequences and potential for malignant transformation, there are multiple reasons for treatment. There is no current agreement on the most efficacious treatment, but 5-fluorouracil has been shown to both prevent and treat AKs, and imiquimod and photodynamic therapy may have the best cosmetic outcomes. AKs may be treated to improve appearance and relieve symptoms, but the keratinocytic dysplasia that gives rise to malignancy, and sometimes appears as an AK, may be what actually threatens patient health. Thus, treatments should aim to decrease the risk of KC or facilitate KC diagnosis by reducing the potential for misidentification created when a KC appears in a field of AKs. Improved agreement among clinicians on AK definition may improve management.

Validation of Photograph-Based Toxicity Score for Topical 5-Fluorouracil Cream Application

BACKGROUND

An objective tool quantifying the toxicity of 5-fluorouracil (5-FU) from photographs was recently reported, and its reliability was confirmed.

OBJECTIVE

The aim of this study was to validate the photograph-based toxicity score.

METHODS

Photograph-based toxicity scores of participants assigned to the 5-FU arm of a randomized placebo-controlled trial were tested for correlations with their patient-reported symptom scores and baseline characteristics.

RESULTS

Each pair of individual and overall scores of patient-reported symptoms and photograph-based toxicity was correlated at 2 and 4 weeks (correlation coefficient range, 0.34-0.95; P < .001 for all). Older age, more actinic keratoses, previous topical 5-FU use, and more keratinocyte carcinomas on the face and ears in the previous 5 years were correlated with increased 5-FU toxicity at 2 weeks (P < .05). An increase in the total number of 5-FU applications during the trial was correlated with less severe toxicity at 2 weeks (P < .001), but with increased toxicity at 4 weeks (P < .001).

CONCLUSION

This study provides evidence for construct validity of the photograph-based 5-FU toxicity score. The tool can be used to objectively measure 5-FU toxicity in clinical or research setting, and it can be a prototype for toxicity measurements of other topical medications.

Measuring the severity of topical 5-fluorouracil toxicity

BACKGROUND

Topical 5% 5-fluorouracil (5-FU) is known to cause toxicity, such as erythema, pain, and crusting/erosions.

OBJECTIVES

We sought to develop a scale to measure this toxicity and test the scale for reliability.

METHODS

A scale was developed involving four parameters: erythema severity, percentage of face involved in erythema, crusting/erosions severity, and percentage of face involved in crusting/erosions. Thirteen raters graded 99 sets of photographs from the Veterans Affairs Keratinocyte Carcinoma Chemoprevention (VAKCC) Trial using these parameters.

RESULTS

Intraclass correlation overall for 13 raters was 0.82 (95% CI 0.77-0.86). There was no statistically significant trend in reliability by level of training in dermatology.

CONCLUSIONS

This scale is a reliable method of evaluating the severity of toxicity from topical 5-fluorouracil and can be used by dermatologists and nondermatologists alike.

Compact fluorescent lamps and risk of skin cancer

BACKGROUND

Previously considered safe for typical use, concerns have recently been expressed regarding the potential effect of compact fluorescent lamps (CFLs) on human skin and, in particular, on skin cancer risk.

OBJECTIVE

We sought to address this concern by reviewing the current literature on CFLs, ultraviolet (UV) radiation, and photocarcinogenic exposure.

RESULTS

On average, the UV radiation from CFLs and subsequent carcinogenic exposure is lower than that from incandescent bulbs. However, defective bulbs can emit higher levels of UV radiation, which may cause significant damage.

CONCLUSION

Our review calls for further investigation to determine how frequently these bulbs are sufficiently defective to lead to adverse effects.

Changing incidence trends of cutaneous T-cell lymphoma

IMPORTANCE

Cutaneous T-cell lymphoma (CTCL) incidence and survival have been increasing steadily for over 25 years.

OBJECTIVE

We sought to measure changes in CTCL incidence trends and survival rates.

DESIGN, SETTING, AND PARTICIPANTS

Population-based study. The CTCL incidence and survival data were obtained from the 9 original registries (1973-2009) and the 4 additional registries (1992-2009) of the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute (NCI). Trend analysis was performed using the Joinpoint Regression Program provided by the NCI. Survival analysis was performed using the SeerSTAT statistical software of the NCI. The total number of cases of CTCL from 1973 to 2009 was 6230.

MAIN OUTCOMES AND MEASURES

Diagnoses of CTCL.

RESULTS

Overall CTCL incidence has stabilized since 1998 (95% CI, 1994-2002), with an annual percent change (APC) of 5.7% from 1973 to 1998 (95% CI, 4.9%-6.5%) and an APC of 0.1% from 1998 to 2009 (95% CI, -1.4% to 1.5%). Similar incidence stabilization patterns were found in subgroup analyses of race, sex, age, diagnosis, and registry. Five-year CTCL survival rates increased until 2004.

CONCLUSIONS AND RELEVANCE

The incidence of CTCL is no longer increasing. Causes for this trend change may include real incidence stabilization, stabilization of physician detection, or artifact.

Hypertension, obesity and prostate cancer biochemical recurrence after radical prostatectomy

BACKGROUND

The metabolic syndrome (MetS) comprises a constellation of risk factors associated with an increased risk for cardiovascular disease. Components of MetS have emerged as putative risk factors for prostate carcinoma. In this study, we examine the association between three features of the MetS (obesity, hypertension and diabetes) and the risk of biochemical recurrence (BCR) after radical prostatectomy (RP).

METHODS

We examined data from 1428 men in the University of Michigan Prostate Cancer Data Bank who elected to have RP as their primary treatment. We calculated body mass index from patients' weight and height measured at the time of prostate cancer diagnosis. We used the University of Michigan's Electronic Medical Record Search Engine to identify subjects with hypertension and/or diabetes before their prostate cancer diagnosis.

RESULTS

Of 1428 men who underwent RP, 107 (8%) subsequently developed BCR with a median length of follow-up post-surgery of 3.6 years. Obesity and hypertension were each associated with an increased risk of BCR (adjusted hazard ratio (aHR) = 1.37; 95% CI 0.92-2.09 and aHR = 1.51, 95% CI 1.01-2.26), whereas no association was observed between diabetes and BCR (aHR = 0.73; 95% CI 0.40-1.33).

CONCLUSIONS

Obesity and hypertension were each associated with an increased risk for BCR of prostate cancer after RP, independent of age at diagnosis and tumor pathological features. Given the increasing rates of obesity, hypertension and prostate cancer, a better understanding of the relationship between these entities is of significant public health importance. Elucidation of the involved pathogenic mechanisms will be needed to establish causality.