Validity of self-reported skin screening histories

Screening by whole-body clinical skin examination may improve early diagnosis of melanoma and reduce mortality, but objective scientific evidence of this is lacking. As part of a randomized controlled trial of population screening for melanoma in Queensland, Australia, the authors assessed the validity of self-reported history of whole-body skin examination and factors associated with accuracy of recall among 2,704 participants in 2001. Approximately half of the participants were known to have undergone whole-body skin examination within the past 3 years at skin screening clinics conducted as part of the randomized trial. All positive and negative self-reports were compared with screening clinic records. Where possible, reports of skin examinations conducted outside the clinics were compared with private medical records. The validity of self-reports of whole-body skin examination in the past 3 years was high: Concordance between self-reports and medical records was 93.7%, sensitivity was 92.0%, and specificity was 96.3%. Concordance was lower (74.3%) for self-reports of examinations conducted in the past 12 months, and there was evidence of telescoping in recall for this more recent time frame. In multivariate analysis, women and younger participants more accurately recalled their history of skin examinations. Participants with a history of melanoma did not differ from other participants in their accuracy of recall.

Optimization of a transplant model to assess skin reconstitution from stem cell-enriched primary human keratinocyte populations

Given that an important functional attribute of stem cells in vivo is their ability to sustain tissue regeneration, we set out to establish a simple and easy technique to assess this property from candidate populations of human keratinocyte stem cells in an in vivo setting. Keratinocytes were inoculated into devitalized rat tracheas and transplanted subcutaneously into SCID mice, and the epithelial lining regenerated characterized to establish the validity of this heterotypic model. Furthermore, the rate and quality of epidermal tissue reconstitution obtained from freshly isolated unfractionated vs. keratinocyte stem cell-enriched populations was tested as a function of (a) cell numbers inoculated; and (b) the inclusion of irradiated support keratinocytes and dermal cells. Rapid and sustained epidermal tissue regeneration from small numbers of freshly isolated human keratinocyte stem cells validates the utilization of this simple and reliable model system to assay for enrichment of epidermal tissue-reconstituting cells.

Does chemotherapy improve survival in high-risk Stage I and II Merkel cell carcinoma of the skin?

Purpose: The effectiveness of synchronous carboplatin, etoposide, and radiation therapy in improving survival was evaluated by comparison of a matched set of historic control subjects with patients treated in a prospective Phase II study that used synchronous chemotherapy and radiation and adjuvant chemotherapy. Patients and Methods: Patients were included in the analysis if they had disease localized to the primary site and nodes, and they were required to have at least one of the following high-risk features: recurrence after initial therapy, involved nodes, primary size greater than 1 cm, or gross residual disease after surgery. All patients who received chemotherapy were treated in a standardized fashion as part of a Phase II study (Trans-Tasman Radiation Oncology Group TROG 96:07) from 1997 to 2001. Radiation was delivered to the primary site and nodes to a dose of 50 Gy in 25 fractions over 5 weeks, and synchronous carboplatin (AUC 4.5) and etoposide, 80 mg/m(2) i.v. on Days 1 to 3, were given in Weeks 1, 4, 7, and 10. The historic group represents a single institution's experience from 1988 to 1996 and was treated with surgery and radiation alone, and patients were included if they fulfilled the eligibility criteria of TROG 96:07. Patients with occult cutaneous disease were not included for the purpose of this analysis. Because of imbalances in the prognostic variables between the two treatment groups, comparisons were made by application of Cox's proportional hazard modeling. Overall survival, disease-specific survival, locoregional control, and distant control were used as endpoints for the study. Results: Of the 102 patients who had high-risk Stage I and II disease, 40 were treated with chemotherapy (TROG 96:07) and 62 were treated without chemotherapy (historic control subjects). When Cox's proportional hazards modeling was applied, the only significant factors for overall survival were recurrent disease, age, and the presence of residual disease. For disease-specific survival, recurrent disease was the only significant factor. Primary site on the lower limb had an adverse effect on locoregional control. For distant control, the only significant factor was residual disease. Conclusions: The multivariate analysis suggests chemotherapy has no effect on survival, but because of the wide confidence limits, a chemotherapy effect cannot be excluded. A study of this size is inadequately powered to detect small improvements in survival, and a larger randomized study remains the only way to truly confirm whether chemotherapy improves the results in high-risk MCC. (c) 2006 Elsevier Inc.

Prolonged prevention of squamous cell carcinoma of the skin by regular sunscreen use

Half of all cancers in the United States are skin cancers. We have previously shown in a 4.5-year randomized controlled trial in an Australian community that squamous cell carcinomas (SCC) but not basal cell carcinomas (BCC) can be prevented by regular sunscreen application to the head, neck, hands, and forearms. Since cessation of the trial, we have followed participants for a further 8 years to evaluate possible latency of preventive effect on BCCs and SCCs. After prolonged follow-up, BCC tumor rates tended to decrease but not significantly in people formerly randomized to daily sunscreen use compared with those not applying sunscreen daily. By contrast, corresponding SCC tumor rates were significantly decreased by almost 40% during the entire follow-up period (rate ratio, 0.62; 95% confidence interval, 0.38-0.99). Regular application of sunscreen has prolonged preventive effects on SCC but with no clear benefit in reducing BCC.