Peter K. Lee

Trends in the incidence and treatment of parathyroid cancer in the United States.

Parathyroid cancer is a rare cause of hyperparathyroidism. The objectives of this study were to determine the patterns of disease, treatment trends, and outcomes among patients with parathyroid cancer by using a population‐based data source.

Accuracy of teledermatology for pigmented neoplasms

BACKGROUND Accurate diagnosis and management of pigmented lesions is critical because of the morbidity and mortality associated with melanoma. OBJECTIVE We sought to compare accuracy of store-and-forward teledermatology for pigmented neoplasms with standard, in-person clinic dermatology. METHODS We conducted a repeated measures equivalence trial involving veterans with pigmented skin neoplasms. Each lesion was evaluated by a clinic dermatologist and a teledermatologist; both generated a primary diagnosis, up to two differential diagnoses, and a management plan. The primary outcome was aggregated diagnostic accuracy (match of any chosen diagnosis with histopathology). We also compared the severity of inappropriately managed lesions and, for teledermatology, evaluated the incremental change in accuracy when polarized light dermatoscopy or contact immersion dermatoscopy images were viewed. RESULTS We enrolled 542 patients with pigmented lesions, most were male (96%) and Caucasian (97%). The aggregated diagnostic accuracy rates for teledermatology (macro images, polarized light dermatoscopy, and contact immersion dermatoscopy) were not equivalent (95% confidence interval for difference within +/-10%) and were inferior (95% confidence interval lower bound <10%) to clinic dermatology. In general, the addition of dermatoscopic images did not significantly change teledermatology diagnostic accuracy rates. In contrast to diagnostic accuracy, rates of appropriate management plans for teledermatology were superior and/or equivalent to clinic dermatology (all image types: all lesions, and benign lesions). However, for the subgroup of malignant lesions (n = 124), the rate of appropriate management was significantly worse for teledermatology than for clinic dermatology (all image types). Up to 7 of 36 index melanomas would have been mismanaged via teledermatology. LIMITATIONS Nondiverse study population and relatively small number of melanomas were limitations. CONCLUSIONS In general, the diagnostic accuracy of teledermatology was inferior whereas management was equivalent to clinic dermatology. However, for the important subgroup of malignant pigmented lesions, both diagnostic and management accuracy of teledermatology was generally inferior to clinic dermatology and up to 7 of 36 index melanomas would have been mismanaged via teledermatology. Teledermatology and teledermatoscopy should be used with caution for patients with suspected malignant pigmented lesions.

Risk of another basal cell carcinoma developing after treatment of a basal cell carcinoma

Background: There is an increased risk of new basal cell carcinomas (BCCs) developing in a person who has had a BCC. Objective: This study attempts to define the magnitude of this increased risk. Methods: The charts of 260 white patients with a histologically proven BCC were reviewed for the occurrence of new BCCs. The cumulative 5-year incidence (modified life-table method) for new BCCs developing in these patients was compared with the 5-year incidence in the general white population of the United States. Results: Of the 260 patients, new BCCs developed in 137 within an average of 38.3 months, a 5-year cumulative rate of one or more new BCCs of 45.2%. The yearly risk for new BCCs developing in the study population remained high during the 5-year interval. In the general white population of the United States, the maximal 5-year incidence was calculated to be 5% (p Conclusion: Patients with a history of BCC require life-long follow-up because of the high probability of new BCCs developing.

Cell surface chondroitin sulfate glycosaminoglycan in melanoma: role in the activation of pro-MMP-2 (pro-gelatinase A)

We previously reported that CS (chondroitin sulfate) GAG (glycosaminoglycan), expressed on MCSP (melanoma-specific CS proteoglycan), is important for regulating MT3-MMP [membrane-type 3 MMP (matrix metalloproteinase)]-mediated human melanoma invasion and gelatinolytic activity in vitro. In the present study, we sought to determine if CS can directly enhance MT3-MMP-mediated activation of pro-MMP-2. Co-immunoprecipitation studies suggest that MCSP forms a complex with MT3-MMP and MMP-2 on melanoma cell surface. When melanoma cells were treated with betaDX (p-nitro-beta-D-xylopyranoside) to inhibit coupling of CS on the core protein, both active form and proform of MMP-2 were no longer co-immunoprecipitated with either MCSP or MT3-MMP, suggesting a model in which CS directly binds to MMP-2 and presents the gelatinase to MT3-MMP to be activated. By using recombinant proteins, we determined that MT3-MMP directly activates pro-MMP-2 and that this activation requires the interaction of the C-terminal domain of pro-MMP-2 with MT3-MMP. Activation of pro-MMP-2 by suboptimal concentrations of MT3-MMP is also significantly enhanced in the presence of excess C4S (chondroitin 4-sulfate), whereas C6S (chondroitin 6-sulfate) or low-molecular-mass hyaluronan was ineffective. Affinity chromatography studies using CS isolated from aggrecan indicate that the catalytic domain of MT3-MMP and the C-terminal domain of MMP-2 directly bind to the GAG. Thus the direct binding of pro-MMP-2 with CS through the C-domain would present the catalytic domain of pro-MMP-2 to MT3-MMP, which facilitates the generation of the active form of MMP-2. These results suggest that C4S, which is expressed on tumour cell surface, can function to bind to pro-MMP-2 and facilitate its activation by MT3-MMP-expressing tumour cells to enhance invasion and metastasis.

Reduction in the Incidence of Squamous Cell Carcinoma in Solid Organ Transplant Recipients Treated with Cyclic Photodynamic Therapy

BACKGROUND AND OBJECTIVES Squamous cell carcinomas (SCCs) produce significant morbidity in solid organ transplant recipients (SOTRs), particularly in patients who develop multiple tumors. Topical photodynamic therapy (PDT) has been shown to decrease the number of keratotic lesions in SOTRs, but the duration of the beneficial effect is limited. The aim of this study was to evaluate the potential benefit of cyclic PDT in the prevention of new SCCs in SOTRs. METHODS Twelve high‐risk SOTRs received cyclic PDT treatments at 4‐ to 8‐week intervals for 2 years. The development of new SCCs (invasive and in situ) performed 12 and 24 months after the start of cyclic PDT were compared with the number of SCCs developed during the year before initiation of cyclic PDT. RESULTS The median reduction in the 12‐ and 24‐month post‐treatment counts from the 1‐month pretreatment counts was 79.0% (73.3–81.8%) and 95.0% (87.5–100.0%), respectively. Treatments were well tolerated. CONCLUSION Cyclic PDT with 5‐aminolevulinic acid may reduce the incidence of SCC in SOTRs. Additional studies with larger numbers of patients and optimized protocols are necessary to further explore the potential benefits of cyclic PDT in the prevention of skin cancer in this high‐risk patient population.

Clinical algorithms for the surgical management of locally recurrent rectal cancer.

PURPOSE: Advances in surgical practice have helped expand the options for patients with locally recurrent rectal cancer through improvements in reconstructive options, management of operative complications, addition of intraoperative adjuvant therapies, and postoperative care. This review outlines the presentation and management of patients with locally recurrent rectal cancer, and it describes easy-to-apply clinical algorithms to aid management. METHODS: The electronic literature was searched for studies reporting outcomes for locally recurrent rectal cancer limited to the English language. RESULTS: Prospective and retrospective case series and single-center experiences were identified. A total of 106 articles were selected for full-text review of which 82 fulfilled the inclusion criteria. No randomized studies were identified. We found that multimodality treatment of locally recurrent rectal cancer can improve 5-year survival from 0% to over 40%, and selected patients may survive up to 10 years. A mixture of imaging modalities is used in patient selection for surgery. An R0 resection is consistently a favorable prognostic factor. R1 resection and surgery in the setting of oligometastases compare favorably with nonoperative palliation. Although mortality figures remain low, morbidity is significant and mostly wound related. CONCLUSIONS: Improvements in radiological imaging modalities and technical improvements in surgical and reconstructive options have facilitated more accurate staging, better selection of patients for surgery, reduced morbidity and mortality, and higher R0 resections. Optimal management is in specialist units with a multidisciplinary approach with the use of multimodal therapy.

Failure of Q-switched ruby laser to eradicate atypical-appearing solar lentigo: Report of two cases

Cutaneous lasers, including argon, Q-switched Nd:YAG, Q-switched ruby, Q-switched alexandrite, and short pulsed dye lasers, have been used to treat solar lentigines and other benign melanocytic lesions. However, the effects of these lasers at standard fluences on atypical melanocytic lesions have not been examined. We describe two patients in whom the Q-switched ruby laser failed to successfully treat clinically atypical-appearing solar lentigines. In both, clinically atypical-appearing melanocytic lesions were treated with excellent initial cosmetic results. In the first patient, the pigmentation returned several months after treatment and continued to increase in size and color. A biopsy specimen 30 months after Q-switched ruby laser therapy revealed a lentigo maligna melanoma. In the second patient, the lesion recurred 6 months after Q-switched ruby laser therapy, and a biopsy specimen 1 year after treatment showed an early lentigo maligna. Thus Q-switched ruby lasers and other cutaneous lasers capable of targeting melanin may be inadequate to eliminate lentigo maligna and other atypical melanocytic lesions completely. These cases emphasize the importance of careful clinical assessment before any laser surgery and the need to advise patients to return for evaluation should pigmentation return.

MOCVD in inverted stagnation point flow: I. Deposition of GaAs from TMAs and TMGa

Abstract A new vertical reactor for MOCVD of III–V compounds is described along with the associated computer control system. The reactor geometry is based on an inverted stagnation point flow configuration providing a well defined flow region. Flow and temperature distributions are computed by finite element analysis. GaAs growth rate variations across the substrate are predicted for the case of mass transfer controlled deposition. The growth of GaAs from (CH3)3Ga and (CH3)3As is used to test the experimental system. Single crystalline films with good surface morphology are deposited at 15 and 500 Torr. Predicted and experimentally observed growth rates are compared and demonstrate the strong influence of flow effects on MOCVD reactor performance.

Capecitabine for skin cancer prevention in solid organ transplant recipients

Jirakulaporn T, Endrizzi B, Lindgren B, Mathew J, Lee PK, Dudek AZ. Capecitabine for skin cancer prevention in solid organ transplant recipients.
Clin Transplant 2011: 25: 541–548.

Original articleAccuracy of teledermatology for nonpigmented neoplasms

BACKGROUND Studies of teledermatology utilizing the standard reference of histopathology are lacking. OBJECTIVE To compare accuracy of store-and-forward teledermatology for non-pigmented neoplasms with in-person dermatology. METHODS This study was a repeated-measures equivalence trial involving veterans with non-pigmented skin neoplasms. Each lesion was evaluated by an in-person dermatologist and a teledermatologist; both generated a primary diagnosis, up to two differential diagnoses, and management plan. The primary outcome was aggregated diagnostic accuracy (percent correct matches of any chosen diagnosis with histopathology). Secondary outcomes included management plan accuracy (percent correct matches with expert panel management plan). Additional analyses included evaluation of the incremental effect of using polarized light dermatoscopy in addition to standard macro images, and evaluating benign and malignant lesion subgroups separately. RESULTS Most of the 728 participants were male (97.8%) and Caucasian (98.9%). The aggregated diagnostic accuracy (primary outcome) of teledermatology (macro images) was not equivalent (95% confidence interval [CI] for difference within +/-10%) and was inferior (95% CI lower bound <10%) to in-person dermatology for all lesions and the subgroups of benign and malignant lesions. However, management plan accuracy was equivalent. Teledermatology aggregated diagnostic accuracy using polarized light dermatoscopy was significantly better than for macro images alone (P = .0017). The addition of polarized light dermatoscopy showed the same pattern for malignant lesions, but not for benign lesions. Most interestingly, for malignant lesions, the addition of polarized light dermatoscopy yielded equivalent aggregated diagnostic accuracy rates. LIMITATIONS Non-diverse study population. CONCLUSIONS Using macro images, the diagnostic accuracy of teledermatology was inferior to in-person dermatology, but accuracy of management plans was equivalent. The addition of polarized light dermatoscopy yielded significantly better aggregated diagnostic accuracy, but management plan accuracy was not significantly improved. For the important subgroup of malignant lesions, the addition of polarized light dermatoscopy yielded equivalent diagnostic accuracy between teledermatologists and clinic dermatologists.