Regulation of apoAI processing by procollagen C-proteinase enhancer-2 and bone morphogenetic protein-1

Given the increased prevalence of cardiovascular disease in the world, the search for genetic variations controlling the levels of risk factors associated with the development of the disease continues. Multiple genetic association studies suggest the involvement of procollagen C-proteinase enhancer-2 (PCPE2) in modulating HDL-C levels. Therefore biochemical and mechanistic studies were undertaken to determine whether there might be a basis for a role of PCPE2 in HDL biogenesis. Our studies indicate that PCPE2 accelerates the proteolytic processing of pro-apolipoprotein (apo) AI by enhancing the cleavage of the hexapeptide extension present at the N terminus of apoAI. Surface Plasmon Resonance and immunoprecipitation studies indicate that PCPE2 interacts with BMP-1 and pro-apoAI to form a ternary pro-apoAI/BMP-1/PCPE2 complex. The most favorable interaction among these proteins begins with the association of BMP-1 to pro-apoAI followed by the binding of PCPE2 which further stabilizes the complex. PCPE2 resides, along with apoAI, on the HDL fraction of lipoproteins in human plasma supporting a relationship between HDL and PCPE2. Taken together, the findings from our studies identify a new player in the regulation of apoAI post-translational processing and open a new avenue to the study of mechanisms involved in the regulation of apoAI synthesis, HDL levels, and potentially, cardiovascular disease.

Comprehensive whole-genome and candidate gene analysis for response to statin therapy in the Treating to New Targets (TNT) cohort

BACKGROUND

Statins are effective at lowering low-density lipoprotein cholesterol and reducing risk of cardiovascular disease, but variability in response is not well understood. To address this, 5745 individuals from the Treating to New Targets (TNT) trial were genotyped in a combination of a whole-genome and candidate gene approach to identify associations with response to atorvastatin treatment.

METHODS AND RESULTS

A total of 291 988 single-nucleotide polymorphisms (SNPs) from 1984 individuals were analyzed for association with statin response, followed by genotyping top hits in 3761 additional individuals. None was significant at the whole-genome level in either the initial or follow-up test sets for association with low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, or triglyceride response. In addition to the whole-genome platform, 23 candidate genes previously associated with statin response were analyzed in these 5745 individuals. Three SNPs in apoE were most highly associated with low-density lipoprotein cholesterol response, followed by 1 in PCSK9 with a similar effect size. At the candidate gene level, SNPs in HMGCR were also significant though the effect was less than with those in apoE and PCSK9. rs7412/apoE had the most significant association (P=6x10(-30)), and its high significance in the whole-genome study (P=4x10(-9)) confirmed the suitability of this population for detecting effects. Age and gender were found to influence low-density lipoprotein cholesterol response to a similar extent as the most pronounced genetic effects.

CONCLUSIONS

Among SNPs tested with an allele frequency of at least 5%, only SNPs in apoE are found to influence statin response significantly. Less frequent variants in PCSK9 and smaller effect sizes in SNPs in HMGCR were also revealed.

Desmoplastic neurotropic melanoma: a clinicopathologic analysis of 128 cases

BACKGROUND

Several studies have suggested that desmoplastic neurotropic melanoma (DNM) is associated with higher local recurrence rates than other types of melanoma. The authors investigated the local recurrence rates for patients with DNM after surgery alone or surgery followed by radiotherapy (RT).

METHODS

One hundred twenty-eight patients with DNM were treated at the Sydney Melanoma Unit and the Sydney Cancer Center from 1996 to 2007. All patients underwent local excision, 27 patients also received RT. For both groups, clinical and pathologic features, treatment details, and local recurrence data were analyzed.

RESULTS

The median age at diagnosis was 65.5 years. The ratio of men to women was 2.7:1. The head and neck was the most common location (51%). The median Breslow thickness was 4 mm, and 99% of patients had Clark Level IV or V primary tumors. Patients who received adjuvant RT had thicker tumors (P = .003), deeper Clark level invasion (P < .001), and narrower excision margins (P < .001). There were 8 local recurrences, including 6 (6%) in the surgery only group and 2 (7%) in the adjuvant RT group. A positive margin (P < .001) and head and neck location (P = .03) were significant predictors of local recurrence.

CONCLUSIONS

The local recurrence rate in this series was lower than the rates reported in historic control groups and in the authors' previous temporal cohort. The results indicated that clear surgical margins are of paramount importance in minimizing local recurrence; when margins are compromised, the addition of RT may reduce local recurrence rates compared with historic controls. A prospective randomized trial is needed to quantify the risk reduction with adjuvant RT.

Follow-up schedules after treatment for malignant melanoma

BACKGROUND

Existing follow-up guidelines after treatment for melanoma are based largely on dated literature and historical precedent. This study aimed to calculate recurrence rates and establish prognostic factors for recurrence to help redesign a follow-up schedule.

METHODS

Data were retrieved from the Sydney Melanoma Unit database for all patients with a single primary melanoma and American Joint Committee on Cancer (AJCC) stage I-II disease, who had received their first treatment between 1959 and 2002. Recurrence rates, timing and survival were recorded by substage, and predictive factors were analysed.

RESULTS

Recurrence occurred in 18.9 per cent (895 of 4748) of patients overall, 5.2 per cent (95 of 1822) of those with stage IA disease, 18.4 per cent (264 of 1436) with IB, 28.7 per cent (215 of 750) with IIA, 40.6 per cent (213 of 524) with IIB and 44.3 per cent (86 of 194) with IIC disease. Overall, the median disease-free survival time was 2.6 years, but there were marked differences between AJCC subgroups. Primary tumour thickness, ulceration and tumour mitotic rate were important predictors of recurrence.

CONCLUSION

A new follow-up schedule was proposed: stage I annually, stage IIA 6-monthly for 2 years and then annually, stage IIB-IIC 4-monthly for 2 years, 6-monthly in the third year and annually thereafter.

Cytologic features of metastatic and recurrent melanoma in patients with primary cutaneous desmoplastic melanoma

Desmoplastic melanoma (DM) is a rare subtype of melanoma characterized by malignant spindle cells associated with prominent fibrocollagenous stroma. Primary melanomas may be entirely desmoplastic ("pure" DM) or exhibit a desmoplastic component admixed with a nondesmoplastic component ("combined" DM). The cytologic features of only 5 cases of DM have been reported previously. Fine-needle biopsy (FNB) specimens from 20 recurrent or metastatic lesions in patients with cutaneous DM and 20 recurrent or metastatic lesions from patients with primary cutaneous non-DM were examined and compared. FNB specimens of patients with DM were less cellular (P = .009) and less often exhibited intranuclear cytoplasmic invaginations (P = .008) and mitotic figures (P = .006) than specimens from patients with non-DM. "Combined" DMs were more commonly composed of epithelioid cells (P = .017) and less often contained bizarre/giant tumor cells (P = .010) than did "pure" DMs. Recurrent and metastatic DM has a range of cytologic appearances. Awareness of the cytologic features and careful clinicopathologic correlation will assist in accurate FNB diagnosis.

The cost-effectiveness of sentinel node biopsy in patients with intermediate thickness primary cutaneous melanoma

BACKGROUND

The aim of this study was to determine the cost-effectiveness of wide excision (WEX) + sentinel node biopsy (SNB) compared with WEX only in patients with primary melanomas >/=1 mm in thickness.

METHODS

A Markov model was populated with probabilities of disease progression and survival from the published literature. Costs were obtained from diagnostic-related group weightings and health outcomes were measured in quality-adjusted life years (QALYs).

RESULTS

Base case analyses suggested that, over a 20-year timeframe, the mean total cost per patient receiving WEX only was AU $23,182 with 10.45 life years (LY) and 9.90 QALYs. The mean cost per patient for WEX + SNB was AU $24,045 with 10.77 LY and 10.34 QALYs. The incremental cost effectiveness ratio for WEX + SNB was AU $2,770 per LY and AU $1,983 per QALY.

CONCLUSION

WEX + SNB appears to offer an improvement in health outcomes (in both LYs and QALYs) with only a slight increase in cost.

Pathologic examination of sentinel lymph nodes from melanoma patients

In melanoma patients, the sentinel node biopsy (SNB) procedure is a highly accurate staging method, and the tumor-harboring status of the sentinel node (SN) is the most important prognostic factor for patients with early stage disease. For the SN to provide accurate prognostic information, however, it is essential that all "true" SNs are removed and examined diligently. Pathologists should examine multiple hematoxylin-eosin and immunohistochemically stained sections from each SN, but it is unclear from the currently available evidence what is the most appropriate sectioning and staining protocol. Relevant factors to consider include the accuracy of the procedure, the time, labor, and costs involved, and clinical follow-up data which are likely to vary between institutions; hence, individual protocols should be developed locally by pathologists in consultation with their surgical colleagues. At the Sydney Melanoma Unit, four sequential sections of both halves of each SN are examined. The first and fourth sections are stained with hematoxylin-eosin, the second section is stained for S-100 protein, and the third section is stained for HMB-45. Pathologists should not only identify the presence of melanoma metastases within the SN, but also record the size of the largest metastatic focus, tumor penetrative depth (measured from the inner margin of the node capsule to the deepest tumor cell within the SN), and the percentage nodal cross-sectional area involved (as measured on the slides). Potential diagnostic pitfalls in SN evaluation include the misinterpretation of nevus cells, macrophages, or antigen-presenting interdigitating dendritic cells as melanoma. Careful assessment of the morphologic characteristics of the cells and their immunohistochemical profile should prevent misdiagnosis. Routine frozen section examination of SNs from melanoma patients is not recommended. The utility of ultrasound to detect SN metastases (confirmed by fine needle biopsy) is currently being investigated. Whereas potentially this may avoid the need for formal sentinel lymphadenectomy and histopathologic evaluation in some patients, the lack of sensitivity of currently available ultrasound technologies to detect the small micrometastases (<2 mm in diameter), that are typically present in most melanoma patients with a positive SN, limits its current role. In the future, other techniques, such as the use of carbon particles or antimony analysis, may better localize the site of metastases within SNs and permit more focused and efficient pathologic examination of SNs. At present, the role of nonhistopathologic methods of SN evaluation, such as reverse transcription polymerase chain reaction (RT-PCR) and magnetic resonance spectroscopy, remains unclear, and these techniques require further evaluation.

Sentinel lymph node biopsy for melanoma: aspects of pathologic assessment

Sentinel lymph node (SLN) biopsy affords an accurate, minimally invasive means of staging and determining prognosis in patients with melanoma and for identifying those patients who may benefit from complete regional lymph node dissection. Careful and accurate histopathologic assessment of SLNs is critical to achieving optimal reliability of the technique. Micromorphometric parameters of melanoma deposits in SLNs have been shown to be predictive of regional non-SLN involvement and of clinical outcomes. Several non-histopathologic methods of SLN evaluation have been investigated, and while some of them show promise for the future, excision and histopathologic examination currently remains the gold standard for the evaluation of SLNs.

Isolated limb infusion for advanced soft tissue sarcoma of the extremity

BACKGROUND

Isolated limb infusion (ILI) is a minimally invasive technique for delivering high-dose regional chemotherapy. We report our experience with ILI for the treatment of soft tissue sarcoma (STS).

METHODS

From our prospective database, 21 patients with STS of the limb treated with ILI between 1994 and 2007 were identified. In all patients, a high-dose cytotoxic drug combination was used.

RESULTS

There were 14 men, and the median age was 60 years (range, 18-85 years). Eighteen patients (86%) had lower limb tumors. All patients had advanced local disease. The procedure was well tolerated. Fourteen patients (67%) received ILI before definitive surgery. The overall response rate was 90% (complete response [CR] rate 57%, partial response rate 33%). The disease-specific overall survival was 61.9% (median follow-up, 28 months). Only American Joint Committee on Cancer stage was associated with overall survival. The local recurrence rate was 42%. CR and malignant fibrous histiocytoma tumor subtype were associated with a lower local recurrence rate. A lower initial skin temperature (median 35.8 degrees C) was associated with a CR (P = .033). Patients who had a steep increase in intramuscular temperature during the procedure were more likely to have a CR (P = .055). Classification tree analysis identified patients with an initial PaO(2) of >/=194 mmHg as being more likely to have a CR. Ultimately, the overall limb salvage rate was 76%.

CONCLUSION

The outcomes after ILI are comparable to those achieved by conventional isolated limb perfusion. ILI is a minimally invasive alternative to isolated limb perfusion for patients with advanced STS of the extremity.

Keystone flap reconstruction of primary melanoma excision defects of the leg-the end of the skin graft?

BACKGROUND

During the last 4 years, the keystone-design fasciocutaneous island flap has become the principal form of reconstruction in our unit for primary melanoma defects of the leg distal to the knee where primary closure is not possible.

METHODS

Data describing the primary tumor, surgical management, and outcome were collected prospectively for consecutive keystone flap cases. The study's primary end points were complication rates and length of hospital stay.

RESULTS

A total of 176 patients with new primary melanomas of the lower limb were treated over 4 years. The average Breslow thickness was 1.33 mm (range, in situ to 9.0 mm), and the average width of the defect was 3 cm. The reconstructions comprised 106 standard, 65 modified, and 5 double-opposing keystone type flaps performed from the knee to the dorsum of the foot. Complications that required further therapeutic intervention were seen in eight patients (4.6%), with only one partial flap necrosis (.6%) and one total flap loss (.6%). In this series, modification of the flap design significantly decreased the complication rate (Fisher's exact test, P = .033). There was no increase in complications in the distal third of the leg. The procedure was performed in day-only surgery setting in almost a quarter of patients.

CONCLUSION

We present the largest series of flap reconstructions for melanoma of the leg. The keystone flap is extremely reliable, affords excellent cosmesis, and is technically straightforward to perform. At the Sydney Melanoma Unit, reconstruction after primary melanoma excision on the leg has been transformed so that skin grafts are now rarely performed.

Activation of CCR9/CCL25 in cutaneous melanoma mediates preferential metastasis to the small intestine

PURPOSE

Specific chemokines and their respective receptors have been implicated in distant tumor cell metastasis. Cutaneous melanoma has a distinct pattern of metastasis, preferentially targeting the submucosa of the small intestine. However, the underlying pathogenic mechanism remains unknown. Migration of CCR9(+) lymphocytes to the small intestine is known to occur in response to the chemoattractant effects of CCL25 (thymus-expressed chemokine). The integrin heterodimers alphabeta are also known to be important mediators of cellular adhesion. We hypothesize that the mechanism of small intestinal metastasis by melanoma is via the CCR9-CCL25 axis and specific integrins.

EXPERIMENTAL DESIGN

Quantitative reverse transcription-PCR, flow cytometry, and immunohistochemistry were used to assess melanoma tumors for CCR9 and CCL25. Integrin expression was assessed using flow cytometry. CCR9 expression by quantitative reverse transcription-PCR was assessed in primary (n = 23) and metastatic (n = 198) melanomas, and melanoma lines derived from small intestinal metastases (n = 23).

RESULTS

We showed CCR9 expression in 88 of 102 paraffin-embedded metastatic melanomas from the small intestine, 8 of 8 melanoma lines derived from metastases in the small intestine, and 0 of 96 metastatic melanomas from other sites. In vitro migration and invasion studies done on CCR9(+) melanoma lines showed migration in response to CCL25 that was inhibited by anti-CCR9 antibody or by short interfering RNA CCR9. Flow cytometric analysis confirmed CCR9 expression by melanomas to the small intestine and showed concomitant alpha(4)beta(1) integrin expression.

CONCLUSIONS

Our findings show that functionally active CCR9 on melanoma cells facilitates metastasis to the small intestine. The CCR9-CCL25 axis may explain the high incidence of melanoma metastasis to this specific location.

Management of merkel cell carcinoma: the roles of lymphoscintigraphy, sentinel lymph node biopsy and adjuvant radiotherapy

BACKGROUND

Merkel cell carcinoma (MCC) is an uncommon, highly aggressive skin malignancy with a propensity to recur locally and regionally. However, its optimal treatment is uncertain. In this study, we aimed to assess the roles of lymphoscintigraphy and sentinel node (SN) biopsy, as well as radiotherapy, in the treatment of MCC.

PATIENTS AND METHODS

A retrospective analysis of 17 patients diagnosed with MCC (median age 74 years) over a 7-year period (median follow-up 16 months) was performed.

RESULTS

Of 11 patients. 3 had a positive SN biopsy and, despite adjuvant radiotherapy, 2 of these 3 developed regional lymph node (RLN) recurrence. Of the remaining 8 patients who had a negative SN biopsy, however, 5 also had RLN recurrences. There were 9 patients who received adjuvant radiotherapy (RT) to the primary site, with no in-field recurrences; and 8 who received RT to their RLN field, with only 2 developing regional nodal recurrences-both were SN biopsy positive. During the follow-up period, 2 patients died, only 1 due to MCC.

CONCLUSION

The results suggest that SN status may not be an accurate predictor of loco-regional recurrence in MCC. However, they strongly reinforce previous reports that radiotherapy, both locally and to regional nodes, provides effective infield disease control.

Outcomes following isolated limb infusion for melanoma. A 14-year experience

BACKGROUND

Isolated limb infusion (ILI) is a minimally invasive technique for delivering regional chemotherapy in patients with advanced and metastatic melanoma confined to a limb. It is essentially a low-flow isolated limb perfusion (ILP) performed via percutaneous catheters without oxygenation.

METHODS

From our prospective database 185 patients with advanced metastatic melanoma of the limb treated with a single ILI between 1993 and 2007 were identified. In all patients a cytotoxic drug combination of melphalan and actinomycin-D was used. Drug circulation time was 20-30 min under mild hyperthermic conditions (38-39 degrees C).

RESULTS

The majority of patients (62%) were female. Their average age was 74 years (range 29-93 years). Most patients had MD Anderson stage III disease (134/185). The overall response rate was 84% [complete response (CR) rate 38%, partial response rate 46%]. Median response duration was 13 months (22 months for patients with CR; P = 0.01). Median follow-up was 20 months and median survival was 38 months. In those patients with a CR, the median survival was 53 months (P = 0.005). CR rate and survival time decreased with increasing stage of disease. On multivariate analysis significant factors for a favorable outcome were achievement of CR, stage of disease, thickness of primary melanoma, the CO(2 )level in the isolated circuit, and a Wieberdink limb toxicity score of III (considerable erythema and edema).

CONCLUSION

The response rates and duration of response after ILI are comparable to those achieved by conventional ILP. ILI is a minimally invasive alternative to the much more complex and morbid conventional ILP technique for patients with advanced metastatic melanoma confined to a limb.

Detection of second primary cutaneous melanomas

AIMS

There have been few studies investigating the value of follow-up in the detection of second primary melanomas (SPMs) and there is scant information on the role of self-surveillance by the patient. The aim of this study was to assess the frequency of patient detection of both first primary melanomas (FPMs) and SPMs.

PATIENTS AND METHODS

Patients were interviewed to determine who detected their FPM and SPM (in situ or invasive). The associations between clinical and pathological factors and the person who identified the FPM and SPM were examined using multivariate analysis.

RESULTS

One hundred and twelve patients with a recently diagnosed SPM were treated at the Sydney Melanoma Unit (July 2001 to March 2003). Patients detected 59% of the FPMs as compared with 46% of the SPMs. Female gender, greater Breslow tumour thickness and younger age were significant predictors for a patient-detected FPM (Odds Ratio: 4.9 (Confidence Interval 1.5-16.0), 3.2 (1.65-6.04), and 0.9 (0.9-1.0), respectively). Greater tumour thickness and ready visibility of the lesion to the patient were predicting factors for patient detection of a SPM (Odds Ratio: 1.9 (Confidence Interval 1.1-3.3) and 3.6 (1.4-9.1), respectively).

CONCLUSIONS

A history of melanoma does not increase the ability of patients to detect new or thinner primary melanomas themselves. Therefore, patients may benefit from regular clinical review by clinicians, who play an important role in the detection of new melanomas.

[Detection of the first recurrence in patients with melanoma: three quarters by the patient, one quarter during outpatient follow-up]

OBJECTIVE

To evaluate the benefit of frequent outpatient follow-up after the initial diagnosis and treatment of melanoma.

DESIGN

Retrospective study.

METHOD

Patients from the Groningen University Medical Centre with a first recurrence ofa previously treated primary melanoma (American Joint Committee on Cancer stage I-III) were interviewed to determine how many of them had detected the recurrence themselves. Patient data and recurrence characteristics were compared with data from a previous Australian study in order to evaluate the differences between the Dutch and the Australian population.

RESULTS

70 patients with a first recurrence of melanoma were studied. Of the 70 first recurrences, 53 (76%) had been detected by the patient; 10% of the patients had a sign or symptom, but did not detect the recurrence themselves; 11% of the first recurrences were detected as a consequence of self-examination. The proportion of detection by the patient versus detection by a doctor was roughly equal in the Dutch and Australian populations.

CONCLUSION

Three quarters of the first recurrences of a treated melanoma had been detected by the patients themselves, the largest number by accident and only 11% by self-examination. It is not likely that the continuation of frequent follow-up visits will contribute to the detection of recurrences. These findings are no different from the results in the Australian population.