***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    ***EXAMPLES*** 
    Input: Imiquimod is an immune response modifier that acts through Toll-like receptor 7 to induce innate and cell-mediated immune responses . This ongoing phase III , open-label study conducted in Europe is evaluating the long-term ( 5 year ) clinical efficacy and safety of imiquimod 5 % cream applied once daily 5 times per week ( 5 x/week ) for 6 weeks for the treatment of superficial basal cell carcinoma ( sBCC ) . A total of 182 subjects were enrolled . The initial sBCC clearance rate was 90 % ( 12-week post treatment ) , whereas the proportion of subjects who were clinical ly clear at 2 years ( current time point ) was estimated to be 79.4 % . Local skin/application site reactions were the most frequently reported safety findings . Initial efficacy rates of imiquimod applied 5 x/week for 6 weeks demonstrate its clinical utility as an alternative approach to the treatment of sBCC . The recurrence rate seen to date supports ongoing follow up of subjects treated with imiquimod BACKGROUND Superficial basal cell carcinoma ( sBCC ) is an increasingly common tumor in fair-skinned population s throughout the world .  Imiquimod , an immune response modifier that induces cytokines including interferons , has been shown in preliminary studies to have an effect when applied topically to BCC . OBJECTIVE We conducted a multicenter , r and omized , open-label dose-response trial of imiquimod 5 % cream in the treatment of primary sBCC assessing efficacy and safety of different dose regimens . METHODS Ninety-nine patients were r and omized to 6 weeks ' application of imiquimod  in 1 of 4 treatment regimens : twice every day , once every day , twice daily 3 times/week , once daily 3 times/week . The treatment site was excised and examined histologically 6 weeks after cessation of imiquimod . RESULTS Intention-to-treat analysis revealed 100 % ( 3/3 ) histologic clearance in the twice-daily regimen , 87.9 % ( 29/33 ) clearance in the once every day regimen , 73.3 % ( 22/30 ) clearance in the twice-daily 3 times/week regimen , and 69.7 % ( 23/33 ) clearance in the once-daily 3 times/week regimen . Dose-related inflammatory skin reactions at the site of application were common . The majority were well tolerated and only 1 patient withdrew from the trial as a result of a medication-related skin reaction . CONCLUSION Imiquimod 5 % cream appears to have potential as a patient-administered treatment option in sBCC Between January 1991 and December 1992 a phase I trial of superficial photodynamic therapy ( PDT ) using topical application of 5-aminolaevulinic acid ( ALA ) was undertaken to treat Bowen 's disease , superficial basal cell carcinomas ( BCCs ) and metastatic skin secondaries from breast ( adenocarcinoma ) or pinna ( squamous cell carcinoma ) . Promising results were obtained with 36 areas of Bowen 's disease , with a complete response rate of 89 % at a median follow-up of 18 months . The treatment of BCCs was less successful , with 50 % complete responses in 16 lesions at a median follow-up of 17 months . Metastatic nodules responded poorly . The treatment was well tolerated and discomfort during light irradiation could be reduced by prior application of ' Emla ' cream . Lesions wept for 1 - 2 weeks following treatment and healed over a period of approximately 2 months . For large areas of Bowen 's disease , particularly in anatomically difficult areas and in elderly patients , PDT using ALA may constitute a single simple alternative outpatient treatment to existing therapies . Further work is required to improve the results with BCCs BACKGROUND High-energy pulsed carbon dioxide ( CO2 ) lasers have been used extensively to resurface wrinkled and photodamaged skin with a low risk of scarring . Results of histological studies demonstrate precise ablation depths in treated skin with minimal thermal damage to underlying tissue . Our objective was to determine if a pulsed CO2 laser could effectively ablate superficial malignant cutaneous neoplasms ( superficial multifocal basal cell carcinoma [ BCC ] and squamous cell carcinoma [ SCC ] in situ ) . OBSERVATIONS Thirty superficial neoplasms ( 17 BCCs and 13 SCCs ) and their surrounding 3-mm margins were treated with either 2 or 3 passes of a pulsed CO2 laser ( 500 mJ , 2 - 4 W ) using a 3-mm collimated h and piece . The treated areas were subsequently excised and evaluated histologically by serial sectioning at 5-micron intervals for residual tumor at the deep and lateral margins . Average patient age was greater for those with SCCs than for those with BCCs ( 76.5 vs 56.7 years ; P = .001 ) . The average tumor thickness of SCC in situ was significantly greater than that of superficial BCC ( 0.57 vs 0.34 mm ; P = .01 ) . All ( 9 of 9 patients ) BCCs were completely ablated with 3 passes , and residual tumor in the deep margins was seen in 5 of 8 patients treated with 2 passes of the pulsed CO2 laser ( P = .005 ) . Incomplete vaporization of the SCC depth was seen in 3 of 7 patients treated with 3 passes and in 2 of 6 patients treated with 2 passes . Those SCCs incompletely treated were significantly thicker than those completely ablated ( 0.65 vs 0.41 mm ; P = .01 ) . Positive lateral margins were seen in 1 BCC and 3 SCC specimens . CONCLUSIONS Pulsed CO2 laser treatment can be effective in ablating superficial BCC . Treatment of the neoplasm and a minimum of 4-mm margins with 3 passes ( 500 mJ , 2 - 4 W ) is recommended for complete vaporization using this laser system . Because 3 passes did not completely ablate all SCC in situ , use of this modality alone is not recommended for treatment of thick or keratotic lesions . No direct comparison of efficacy can be made with other destructive modalities that have not been evaluated with comparably sensitive histological techniques . Further study is needed to establish any cosmetic advantage of pulsed CO2 lasers over other destructive modalities for treatment of superficial malignant neoplasms and long-term cure rates Objective To evaluate the treatment of superficial basal cell carcinomas ( SBCC ) using photodynamic therapy with topically applied delta-aminolaevulinic acid ( ALA ) and a filtered short arc xenon lamp as a light source . Method An oil-in-water emulsion containing 20 % ALA was applied topically to the lesion sites which were then occluded for 3 h. Irradiation was performed in a single session of 10 min using 125 or 166 mW/cm2 in the wavelength range ( 620–670 nm , giving a radiation dose of 75 or 100 J/cm2 , respectively . Urine sample s obtained in connection with the treatment were examined for traces of porphobilinogen and porphyrin . The therapy outcome was determined by histological examination of punch biopsies or by clinical verification . A follow-up scheduled for 5 years was initiated . Patients A group of 37 patients with histologically verified SBCCs were included . A total of 190 SBCCs were treated . Also included were six patients with 10 nodular basal cell carcinomas and five patients with 18 Mb . Bowen . The urine sample s from three patients showed traces of porphyrins . Results Of the 157 SBCCs followed-up for 6 months , 144 were cleared giving a clearance rate of 92 % . Of the nodular basal cell carcinomas and Mb . Bowens , 2 of ten and 11 of 18 were cleared , respectively . Conclusion Photodynamic therapy is well suited to the treatment of SBCCs giving good cosmetic results regardless of lesion size . The filtered xenon lamp proved to be particularly suitable for photodynamic therapy This multicentre , r and omized study compared photodynamic therapy using topical methyl aminolaevulinate ( MAL PDT ) , a non-invasive modality , with cryotherapy for treatment of  superficial basal cell carcinoma . Sixty patients with 114 lesions were treated with MAL cream ( 160 mg/g ) applied for 3 hours before illumination ( 570 - 670 nm , light dose 75 J/cm ) ( 1 session ) , and 58 with 105 lesions received cryotherapy ( 2 freeze-thaw cycles ) . Patients with an incomplete response at 3 months received 2 further MAL PDT sessions ( n = 20 ) or repeat cryotherapy ( n = 16 ) . 100 lesions treated with  MAL PDT and 93 lesions treated with cryotherapy were in complete response at 3 months after the last treatment and evaluable for recurrence over 5 years . There was no difference in 5-year recurrence rates with either treatment ( 20 % with cryotherapy vs. 22 % with MAL PDT , p = 0.86 ) . However , more patients had an excellent cosmetic outcome with MAL PDT ( 60 % vs. 16 % with cryotherapy , p = 0.00078 ) . These results provide support for the use of MAL PDT as a non-invasive , selective treatment alternative for primary superficial basal cell carcinoma Background Superficial basal cell carcinomas of the skin ( sBCC ) often respond poorly to single‐treatment aminolaevulinic acid‐based photodynamic therapy ( ALA – PDT ) , with a number of reports indicating a relapse rate of 50 % or more We conducted a prospect i ve , multicenter , phase 3 , open-label study to assess long-term sustained clearance of superficial basal cell carcinomas ( sBCCs ) treated with  imiquimod cream 5 % . A biopsy-confirmed tumor ( area > or = 0.5 cm2 and diameter < or = 2.0 cm ) was treated once daily 7 times per week for 6 weeks . Participants with initial clinical clearance at 12 weeks posttreatment were followed for 60 months . Tumor recurrence , serious adverse events ( AEs ) , local skin reactions ( LSRs ) , and skin quality assessment s ( SQAs ) were measured . The initial clearance  rate was 94.1 % ( 159/169 ) . Estimated sustained clearance ( proportion of participants who achieved initial clearance at the 12-week posttreatment visit and remained clinical ly clear at each time point during the long-term follow-up period ; N=157 ) was 85.4 % at 60 months ( life-table method : 95 % confidence interval [ CI ] , 79.3%-91.6 % ) . The overall estimate of treatment success was 80.4 % at 60 months ( N=169 ; 95 % CI , 74.4%-86.4 % ) . Of 20 recurrent tumors , 74 ( 70 % ) occurred within the first 24 months of follow-up . Local skin reactions and application site reactions , the AEs reported by the most participants , occurred predominantly during the treatment period and resolved posttreatment . Compared to baseline , investigator-assessed SQA scores for the target tumor site improved for skin surface abnormalities and hyperpigmentation , and worsened for hypopigmentation . For low-risk sBCCs , daily application of imiquimod for 6 weeks had high initial and 5-year sustained clearance rates Objectives : This study was design ed to compare the safety and efficacy of two cycled dosing regimens of imiquimod 5 % cream for treatment of superficial basal cell carcinoma ( sBCC ) . Methods : Patients ( n = 32 ) were r and omized to receive one of two treatment regimens : 8 weeks of treatment with once‐daily dosing for alternate weeks ( R1 ) and 5 weeks of once‐daily dosing with a 1‐week interval in the middle of the course ( R2 ) . Efficacy measures were tumour clearance at weeks 19 and 52 and measures of patients ' acceptability . Results : Data from 30 patients ( 13 females ) , 14 on R1 and 16 on R2 , were analysed . The results revealed an initial clearance rate of 64 % at week 19 for R1 and 81 % for R2 ( 95 % CI for difference : −14 % to 45 % , p = 0.21 ) . However , clearance rates at week 52 were significantly different : 43 % for R1 and 88 % for R2 ( 95 % CI for difference : 11 % to 68 % , p = 0.02 ) . There was no difference in acceptability of treatment as measured by composite median visual analogue scores at week 8 . Conclusion : Five weeks of 5 % imiquimod cream once daily with a 1‐week interval was more effective but as well tolerated as the 8‐week alternate week regimen for sBCC Summary Background Imiquimod 5 % cream has been investigated for non‐surgical treatment of superficial and nodular basal cell carcinoma ( BCC ) tumours OBJECTIVE To investigate the incidence of single and multiple basal cell carcinoma ( BCC ) lesions  and associated risk factors . DESIGN A prospect i ve , population -based cohort study ( from January 1 , 1990 , through December 31 , 2007 ) . SETTING Two cohorts of 10 994 Dutch people 
    Output:
    
Pooled estimates from r and omized and nonr and omized studies showed similar tumour-free survival at 1 year for imiquimod and PDT .
The PDT tumour-free survival was higher in studies with repeated treatments .