A randomized parallel study to assess the safety and efficacy of two different dosing regimens of 5% imiquimod in the treatment of superficial basal cell carcinoma

Imiquimod as Local Immunotherapy in the Management of Premalignant Cutaneous Conditions and Skin Cancer

Cutaneous cancers are, by far, the most common malignant neoplasms of the human being. Due to the great array of clinical conditions, their worldwide increasing incidence and the steady ageing of the population, non-invasive treatments modalities that show a good clinical response, a proper benefit-risk ratio and cosmetic results are becoming increasingly important in the clinical setting. Imiquimod is a topically applied immunomodulator which is often used in the management of several premalignant and malignant cutaneous disorders. This article is a review of the current literature on its mechanism of action, pharmacokinetics, and therapeutical effects.

Interventions for basal cell carcinoma: abridged Cochrane systematic review and GRADE assessments

BACKGROUND

Basal cell carcinoma (BCC) is the most common cancer affecting white-skinned individuals, and the worldwide incidence is increasing. Although rarely fatal, BCC is associated with significant morbidity and costs.

OBJECTIVES

To assess the effects of interventions for primary BCC in immunocompetent adults.

METHODS

We updated our searches of the following databases to November 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and LILACS. Certainty of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation method. We used standard methodological procedures expected by Cochrane.

RESULTS

We included 52 randomized controlled trials with 6990 participants (median age 65 years; range 20-95). Mean study duration was 13 months (range 6 weeks-10 years). Ninety-two per cent (n = 48/52) of studies exclusively included histologically low-risk BCC (nodular and superficial subtypes). The certainty of evidence was predominantly low or moderate for the outcomes of interest. Overall, surgical interventions have the lowest recurrence rates, and there may be slightly fewer recurrences with Mohs micrographic surgery over surgical excision for primary, facial BCC (high-risk histological subtype or located in the 'H-zone' or both) (low-certainty evidence). Nonsurgical treatments, when used for low-risk BCC, are less effective than surgical treatments, but recurrence rates are acceptable and cosmetic outcomes are probably superior.

CONCLUSIONS

Surgical interventions have lower recurrence rates and remain the gold standard for high-risk BCC. Of the nonsurgical treatments, topical imiquimod has the best evidence to support its efficacy for low-risk BCC. Priorities for future research include agreement on core outcome measures and studies with longer follow-up.

Interventions for basal cell carcinoma of the skin

BACKGROUND

Basal cell carcinoma (BCC) is the commonest cancer affecting white-skinned individuals, and worldwide incidence is increasing. Although rarely fatal, BCC is associated with significant morbidity and costs. First-line treatment is usually surgical excision, but alternatives are available. New published studies and the development of non-surgical treatments meant an update of our Cochrane Review (first published in 2003, and previously updated in 2007) was timely.

OBJECTIVES

To assess the effects of interventions for BCC in immunocompetent adults.

SEARCH METHODS

We updated our searches of the following databases to November 2019: Cochrane Skin Group Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, and LILACS.

SELECTION CRITERIA

Randomised controlled trials (RCTs) of interventions for BCC in immunocompetent adults with histologically-proven, primary BCC. Eligible comparators were placebo, active treatment, other treatments, or no treatment.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Primary outcome measures were recurrence at three years and five years (measured clinically) (we included recurrence data outside of these time points if there was no measurement at three or five years) and participant- and observer-rated good/excellent cosmetic outcome. Secondary outcomes included pain during and after treatment, early treatment failure within six months, and adverse effects (AEs). We used GRADE to assess evidence certainty for each outcome.

MAIN RESULTS

We included 52 RCTs (26 new) involving 6690 participants (median 89) in this update. All studies recruited from secondary care outpatient clinics. More males than females were included. Study duration ranged from six weeks to 10 years (average 13 months). Most studies (48/52) included only low-risk BCC (superficial (sBCC) and nodular (nBCC) histological subtypes). The majority of studies were at low or unclear risk of bias for most domains. Twenty-two studies were industry-funded: commercial sponsors conducted most of the studies assessing imiquimod, and just under half of the photodynamic therapy (PDT) studies. Overall, surgical interventions have the lowest recurrence rates. For high-risk facial BCC (high-risk histological subtype or located in the facial 'H-zone' or both), there may be slightly fewer recurrences with Mohs micrographic surgery (MMS) compared to surgical excision (SE) at three years (1.9% versus 2.9%, respectively) (risk ratio (RR) 0.64, 95% confidence interval (CI) 0.16 to 2.64; 1 study, 331 participants; low-certainty evidence) and at five years (3.2% versus 5.2%, respectively) (RR 0.61, 95% CI 0.18 to 2.04; 1 study, 259 participants; low-certainty evidence). However, the 95% CI also includes the possibility of increased risk of recurrence and no difference between treatments. There may be little to no difference regarding improvement of cosmetic outcomes between MMS and SE, judged by participants and observers 18 months post-operatively (one study; low-certainty evidence); however, no raw data were available for this outcome. When comparing imiquimod and SE for nBCC or sBCC at low-risk sites, imiquimod probably results in more recurrences than SE at three years (16.4% versus 1.6%, respectively) (RR 10.30, 95% CI 3.22 to 32.94; 1 study, 401 participants; moderate-certainty evidence) and five years (17.5% versus 2.3%, respectively) (RR 7.73, 95% CI 2.81 to 21.3; 1 study, 383 participants; moderate-certainty evidence). There may be little to no difference in the number of participant-rated good/excellent cosmetic outcomes (RR 1.00, 95% CI 0.94 to 1.06; 1 study, 326 participants; low-certainty evidence). However, imiquimod may result in greater numbers of good/excellent cosmetic outcomes compared to SE when observer-rated (60.6% versus 35.6%, respectively) (RR 1.70, 95% CI 1.35 to 2.15; 1 study, 344 participants; low-certainty evidence). Both cosmetic outcomes were measured at three years. Based on one study of 347 participants with high- and low-risk primary BCC of the face, radiotherapy may result in more recurrences compared to SE under frozen section margin control at three years (5.2% versus 0%, respectively) (RR 19.11, 95% CI 1.12 to 325.78; low-certainty evidence) and at four years (6.4% versus 0.6%, respectively) (RR 11.06, 95% CI 1.44 to 84.77; low-certainty evidence). Radiotherapy probably results in a smaller number of good participant- (RR 0.76, 95% CI 0.63 to 0.91; 50.3% versus 66.1%, respectively) or observer-rated (RR 0.48, 95% CI 0.37 to 0.62; 28.9% versus 60.3%, respectively) good/excellent cosmetic outcomes compared to SE, when measured at four years, where dyspigmentation and telangiectasia can occur (both moderate-certainty evidence). Methyl-aminolevulinate (MAL)-PDT may result in more recurrences compared to SE at three years (36.4% versus 0%, respectively) (RR 26.47, 95% CI 1.63 to 429.92; 1 study; 68 participants with low-risk nBCC in the head and neck area; low-certainty evidence). There were no useable data for measurement at five years. MAL-PDT probably results in greater numbers of participant- (RR 1.18, 95% CI 1.09 to 1.27; 97.3% versus 82.5%) or observer-rated (RR 1.87, 95% CI 1.54 to 2.26; 87.1% versus 46.6%) good/excellent cosmetic outcomes at one year compared to SE (2 studies, 309 participants with low-risk nBCC and sBCC; moderate-certainty evidence). Based on moderate-certainty evidence (single low-risk sBCC), imiquimod probably results in fewer recurrences at three years compared to MAL-PDT (22.8% versus 51.6%, respectively) (RR 0.44, 95% CI 0.32 to 0.62; 277 participants) and five years (28.6% versus 68.6%, respectively) (RR 0.42, 95% CI 0.31 to 0.57; 228 participants). There is probably little to no difference in numbers of observer-rated good/excellent cosmetic outcomes at one year (RR 0.98, 95% CI 0.84 to 1.16; 370 participants). Participant-rated cosmetic outcomes were not measured for this comparison. AEs with surgical interventions include wound infections, graft necrosis and post-operative bleeding. Local AEs such as itching, weeping, pain and redness occur frequently with non-surgical interventions. Treatment-related AEs resulting in study modification or withdrawal occurred with imiquimod and MAL-PDT.

AUTHORS' CONCLUSIONS

Surgical interventions have the lowest recurrence rates, and there may be slightly fewer recurrences with MMS over SE for high-risk facial primary BCC (low-certainty evidence). Non-surgical treatments, when used for low-risk BCC, are less effective than surgical treatments, but recurrence rates are acceptable and cosmetic outcomes are probably superior. Of the non-surgical treatments, imiquimod has the best evidence to support its efficacy. Overall, evidence certainty was low to moderate. Priorities for future research include core outcome measures and studies with longer-term follow-up.

Nonsurgical Treatments for Nonmelanoma Skin Cancer

Although surgical intervention remains the standard of care for nonmelanoma skin cancer, other treatment modalities have been studied and used. Nonsurgical treatment methods include cryotherapy, topical medications, photodynamic therapy, radiation therapy, Hedgehog pathway inhibitors, programmed cell death protein 1 inhibitors, and active nonintervention. Despite the favorable efficacy of surgical treatment methods, many factors, including but not limited to patient age, preference, and severity of disease, must be taken into consideration when choosing the most appropriate, patient-centered treatment approach.

A Review on Imiquimod Therapy and Discussion on Optimal Management of Basal Cell Carcinomas

Basal cell carcinoma (BCC) is the most common type of skin cancer with an increasing incidence. However, it is still poorly researched compared to many other human diseases. Today, cutaneous neoplasms are a frequent, major problem faced by medical professionals. BCC tumors can cause extensive cosmetic distress as well as disfigurement to patients especially when on the face. Treatment options include surgery, systemic agents, and topical agents. Over the past few decades more studies have been performed to evaluate the utility of topical imiquimod therapy for treatment of BCC. Imiquimod is a toll-like receptor that modifies the immune response via the up-regulation of cytokines and has the capacity to improve a person's immune response. Multiple clinical studies have demonstrated the ability of topical imiquimod to diminish or even eradicate basal cell carcinoma. Given this variety of treatment options and the need for noninvasive options, this review is focused on summarizing the existing information available on the use of imiquimod for BCC and comparing it to other treatment modalities. While excision is the first line treatment and often has greater success with regards to clearance, imiquimod has been shown to be an efficacious treatment modality for BCC. Imiquimod therapy has been shown to be a less invasive and cheaper option than many other treatment modalities. It may be used as either monotherapy or in combination with other treatments, though occlusion has not been shown to be helpful. Several dosing regimens have been studied in the literature. Dosing should take into account factors such as the type of BCC, location, and physician/patient comfort with the regimen. Variability in response to treatment with imiquimod amongst studies suggests that response to treatment may depend on location of lesion, thus more research must be done in this area.

Basal cell carcinoma pathogenesis and therapy involving hedgehog signaling and beyond

Basal cell carcinoma (BCC) of the skin is driven by aberrant hedgehog signaling. Thus blocking this signaling pathway by small molecules such as vismodegib inhibits tumor growth. Primary cilium in the epidermal cells plays an integral role in the processing of hedgehog signaling-related proteins. Recent genomic studies point to the involvement of additional genetic mutations that might be associated with the development of BCCs, suggesting significance of other signaling pathways, such as WNT, NOTCH, mTOR, and Hippo, aside from hedgehog in the pathogenesis of this human neoplasm. Some of these pathways could be regulated by noncoding microRNA. Altered microRNA expression profile is recognized with the progression of these lesions. Stopping treatment with Smoothened (SMO) inhibitors often leads to tumor reoccurrence in the patients with basal cell nevus syndrome, who develop 10-100 of BCCs. In addition, the initial effectiveness of these SMO inhibitors is impaired due to the onset of mutations in the drug-binding domain of SMO. These data point to a need to develop strategies to overcome tumor recurrence and resistance and to enhance efficacy by developing novel single agent-based or multiple agents-based combinatorial approaches. Immunotherapy and photodynamic therapy could be additional successful approaches particularly if developed in combination with chemotherapy for inoperable and metastatic BCCs.

Facial Basal Cell Carcinoma Treated with Topical 5% Imiquimod Cream with Dermoscopic Evaluation

Basal cell carcinoma (BCC) is the most common skin cancer worldwide. Surgical excision is considered to be the primary therapeutic modality wherever possible. For inoperable cases, 5% imiquimod seems to be a good alternative. We present two cases of nodular pigmented BCCs on the face in elderly women successfully treated with 5% imiquimod cream application resulting in complete clinical clearance of lesion as well as on histology and dermatoscopy. There was no recurrence of the lesion on 2 years follow-up for the first and 1.5 years for the second patient.

Non-melanoma Skin Cancer in Canada Chapter 4: Management of Basal Cell Carcinoma

Background

Basal cell carcinoma (BCC) is the most common malignancy. Growth of BCCs leads to local destruction of neighbouring healthy skin and underlying tissue and can result in significant functional and cosmetic morbidity.

Objective

To provide guidance to Canadian health care practitioners regarding management of BCCs.

Methods

Literature searches and development of graded recommendations were carried out as discussed in the accompanying Introduction.

Results

Although BCCs rarely metastasize“ they can be aggressive and disfiguring. This chapter describes the natural history and prognosis of BCCs. Risk stratification is based on clinical features” including the site and size of the tumour“ its histologic subtype (nodular vs sclerosing)” and its history of recurrence.

Conclusions

Various options should be considered for BCC treatment” including cryosurgery” curettage” and topical or photodynamic approaches, as well as fixed-margin surgery and Mohs micrographic surgery. Stratification of recurrence risk for individual BCCs determines the most appropriate therapeutic course.

Basal cell carcinoma: an evidence-based treatment update

BACKGROUND

Basal cell carcinoma (BCC) is the most common skin cancer. Surgical excision remains the standard of treatment, but several alternative treatment modalities exist.

OBJECTIVES

This review aims to provide a current analysis of evidence for the treatment of BCC; specifically, which treatments have the lowest recurrence rates and the best cosmetic outcomes.

METHODS

We searched PubMed (January 1946 to August 2013), Ovid MEDLINE (2003-August 2013), the Cochrane Central Register of Controlled Trials (January 1993 to August 2013), and the Cochrane Database of Systematic Reviews (The Cochrane Library Issue 9, 2013) databases for randomized controlled trials, systematic reviews, or comparative studies for the treatment of BCC.

RESULTS

We found 615 potential articles. Two independent reviewers selected 40 studies: 29 randomized controlled trials (RCTs), seven systematic reviews, and four nonrandomized prospective trials. Treatment modalities reviewed include surgical therapy, radiotherapy and cryotherapy, photodynamic therapy (PDT), topical imiquimod, topical 5-fluorouracil (5-FU), topical solasodine glycoalkaloids, topical ingenol mebutate, intralesional 5-FU, intralesional interferon (IFN), and oral hedgehog pathway inhibitors.

CONCLUSIONS

The available data suggest that surgical methods remain the gold standard in BCC treatment, with Mohs micrographic surgery typically utilized for high-risk lesions. Suitable alternate treatment options for appropriately selected primary low-risk lesions may include PDT, cryotherapy, topical imiquimod, and 5-FU. Radiotherapy is a suitable alternate for surgical methods for treatment in older patient populations. Electrodesiccation and curettage (ED&C) is a commonly used primary treatment option for low-risk lesions; however, there were no RCTs examining ED&C that met our inclusion criteria. New hedgehog pathway inhibitors are promising for the management of advanced BCC; however, side effects are a concern for some patients, and much remains to be learned regarding optimal treatment length, risk of recurrence, and potential development of resistance. There is insufficient evidence at present to make recommendations on topical solasodine glycoalkaloids, topical ingenol mebutate, and intralesional 5-FU and IFN-α. Overall continued research on the efficacy of treatment modalities is needed. In particular, studies should include histologic ascertainment of clearance, long-term follow-up, stratification based on tumor subtype, and comparison with surgical outcomes.

Non-melanoma skin cancers: photodynamic therapy, cryotherapy, 5-fluorouracil, imiquimod, diclofenac, or what? Facts and controversies

Surgical modalities-excision, Mohs micrographic surgery, and electrodesiccation with curettage-are the preferred treatments for nonmelanoma skin cancer (NMSC). When used within guidelines, they have cure rates greater than 90%. Despite this, many other treatments have been studied and utilized for NMSC. We present a comprehensive review of the literature on these topical treatments. Photodynamic therapy (PDT) is administered under numerous and significantly varied regimens, and there are a wide range of cure rates reported. Even with aggressive regimens, PDT is not as effective as surgery is, and it is not a first-line therapy for NMSC. The cryotherapy regimen aggressive enough to adequately treat NMSC carries adverse effects and cosmetic outcomes poor enough to negate its usefulness. Topical 5-fluorouracil and imiquimod are efficacious and safe for the treatment of superficial basal cell carcinoma (BCC) but not other BCC subtypes or squamous cell carcinoma. They are self-administered twice daily for several weeks; therefore, patient and tumor selection are vital to ensuring adherence. There are currently insufficient data to support the use of topical diclofenac and ingenol mebutate for NMSC.

Network geometry shows evidence sequestration for medical vs. surgical practices: treatments for basal cell carcinoma

OBJECTIVES

Basal cell carcinoma (BCC) is the most common cancer with 2 million treatments per year with little evidence-based guidelines for treatment. There are three classes of interventions (surgical, destructive, and topical) for BCC, and this study aimed to determine whether there are preferences or avoidances in comparisons of different types of treatments for BCC in randomized controlled trials (RCTs).

STUDY DESIGN AND SETTING

PubMed, Cochrane Central Registry of Clinical Trials, and ClinicalTrials.Gov were used to identify eligible published and registered ongoing RCTs.

RESULTS

Fifty-five trials (42 published and 13 registered trials) were identified. Only one unpublished registered trial compared a topical vs. a surgical intervention, and only one trial compared a topical vs. a destructive intervention. Conversely, 44 of the 55 trials compared interventions within the same treatment class and 9 of 55 trials compared surgical vs. destructive interventions. In most trials, selection of same-class comparators was not necessitated by the type of BCC lesions (nonaggressive superficial or nodular vs. aggressive, infiltrative, morpheic BCCs, P = 0.155) or their location (face vs. nonfacial, P = 0.137).

CONCLUSION

This is the first time that an evaluation of network geometry is applied to address issues of comparisons between different families of interventions that belong to different specialties and practices (medical vs. surgical). Previous evaluations of homophily have addressed different families of interventions, in which all interventions are medical (drugs) and performed in the same health-care settings. The noncommunicating bodies of evidence between medical and surgical interventions that we document highlight a problem of unnecessary sequestration of the evidence and the corresponding health-care practices.

Management of superficial basal cell carcinoma: focus on imiquimod

Superficial basal cell carcinoma comprise up to 25% of all histological sub-types. They are more likely to occur on younger persons and females and although generally more common on the trunk, also occur frequently on the exposed areas of the head and neck especially in areas of high sun exposure. In the last decade, new treatment options such as topical applications that modify the immune response have been trialed for effectiveness in treating these lesions. Imiquimod 5% cream has been shown to stimulate the innate and cell mediated immune system. The short-term success of imiquimod 5% cream in randomized controlled trials comparing different treatment regimes and dosing as a treatment for small superficial basal cell carcinoma (BCC) not on the face or neck is in the range of 82% for 5 times per week application. A high proportion of participants with good response rates to topical treatment (58%–92%) experience local side effects such as itching and burning, less commonly erosion and ulceration, but the proportion of participants ceasing treatment has not been high. To date one long-term study indicates a treatment success rate of 78%–81% and that initial response is a predictor of long-term outcome. Recurrences tend to occur within the first year after treatment. Future research will compare this preparation to the gold standard treatment for superficial BCC – surgical excision.

[Alternative to surgery in basal cell carcinoma in the elderly population: imiquimod 5% cream]

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer. The incidence of this entity increases with age, peaking at the age of 70 years. This study included 97 patients aged more than 65 years old, with a diagnosis of BCC. These patients were treated with imiquimod applied three times weekly for 6 weeks. Clinical remission was 67% after 10 weeks and was 49.5% after 1 year. Imiquimod is a highly interesting therapeutic modality in the elderly, in whom surgery is often contraindicated. This regimen eradicates a high percentage of tumors and reduces local adverse effects, which are poorly tolerated by aged skin.