Effect of the time interval between melanoma diagnosis and sentinel node biopsy on the size of metastatic tumour deposits in node-positive patients

INTRODUCTION

This study sought to assess whether the interval between diagnostic excision-biopsy of a primary melanoma and definitive wide excision with sentinel node biopsy (SNB) influenced the size of SN metastatic deposits, which might have implications for management and prognosis.

METHODS

Data were collected for (i) a Dutch population-based cohort of patients treated between 2004 and 2014 who underwent SNB within 100 days of complete excision of their primary melanoma and who were SN-positive with known SN metastasis diameter (n = 1027) and (ii) a cohort from a large Australian melanoma treatment centre (n = 541) who presented in the same time period. The effects of SNB timing on the size of SN metastatic deposits were analysed.

RESULTS

Dutch patients whose SNB was performed in the second or third months after diagnosis had significantly larger SN metastasis diameters than patients who had their SNB in the first month (median increases of 17% (95%CI -14, 60%, p = 0.211) and 71% (95%CI 15, 119%, p = 0.004), respectively). No significant difference in tumour diameter for early and late SNB was found in the Australian cohort.

CONCLUSIONS

SN metastasis diameter became progressively greater with SN biopsy in the second and third months after primary melanoma diagnosis in the larger, population-based patient cohort. An increase in metastasis diameter was not observed in the smaller, institutional cohort, possibly due to detection of larger SN metastases by routine pre-operative ultrasound, with fine-needle biopsy confirmation. These patients did not proceed to SNB and were therefore not included in the study.

Correlation between initial tumour volume and treatment duration on Dabrafenib: observation study of subjects with BRAF mutant melanoma on the BRF112680 trial

BACKGROUND

Planar-based measurements of lesions in metastatic melanoma have limitations in estimating tumor burden of a patient and in predicting response to treatment. Volumetric imaging might add predictive value to Response criteria in Solid Tumor (RECIST)-measurement. Based on clinical observations, we explored the association between baseline tumor volume (TV) and duration of treatment with dabrafenib in patients with metastatic melanoma. We have also explored the prognostic value of TV for overall survival (OS) and progression free survival (PFS).

METHODS

This is a retrospective, chart-review of primary source documents and medical imaging of a cohort of patients participating in the BRF112680 phase 1 clinical trial at the Prince of Wales Hospital. TV was quantified by contouring all the measurable baseline target lesions in the standard manner for radiation planning using Voxxar™ software. We used Cox regression models to analyse associations between TV and duration of treatment with dabrafenib and between TV, PFS and OS.

RESULTS

Among 13 patients of BRAF 112680 trial, 10 were included in the retrospective analysis. Target lesion sum volume ranged from 0.3 to 1065.5 cm³ (cc), with a median of 27.5 cc. The median PFS and OS were 420 days (range 109-1765) and 1680 days (range 390-2940), respectively. The initial TV was inversely correlated with duration of treatment with dabrafenib (rho - 0.6; P 0.03). In multivariate analysis, TV was a predictor for OS (HR 2.81 CI 1.06-6.19) and PFS (8.76 (CI 1.05-43.58). Patients with tumour volume above the median had significantly lower OS of 6-months compared to 56-months survival for patients with smaller volumes; P = 0.019.

CONCLUSIONS

TV is a predictor for treatment duration and is prognostic of OS and PFS in patients with metastatic melanoma. These findings need to be validated prospectively in clinical trials.

Tumor volume as a prognostic factor in resectable malignant melanoma

BACKGROUND

Vertical tumor thickness according to Breslow and histological ulceration are still the most powerful predictors for the clinical outcome of resectable cutaneous malignant melanoma (MM) without lymph node infiltration. It has been proposed that tumor volume in MM may also be of prognostic relevance.

METHODS

We retrospectively analyzed the prognostic impact of tumor volume and other established risk factors in 122 MM patients with a median follow-up period of 39.7 months.

RESULTS

We found the logarithmic tumor volume to be a better prognostic factor compared to Breslow tumor thickness in multivariate analysis. MM with a tumor volume below a threshold of 140 mm(3) had a significantly higher relapse-free survival after 5 years of 98% compared to 47% in larger MMs (p < 0.0001).

CONCLUSION

In some melanomas with a low tumor thickness, a higher tumor volume appeared to be linked to a higher risk of disease recurrence. Inclusion of tumor volume into the risk assessment of resectable MM may be of benefit in the future.

Digital image analysis: a review of reproducibility, stability and basic requirements for optimal results

Digital image analysis (DIA) is increasingly implemented in histopathological research to facilitate truly quantitative measurements, decrease inter-observer variation and reduce hands-on time. Originally, efforts were made to enable DIA to reproduce manually obtained results on histological slides optimized for light microscopy and the human eye. With improved technical methods and the acknowledgement that computerized readings are different from analysis by human eye, recognition has been achieved that to really empower DIA, histological slides must be optimized for the digital 'eye', with reproducible results correlating with clinical findings. In this review, we focus on the basic expectations and requirements for DIA to gain wider use in histopathological research and diagnostics. With a reference to studies that specifically compare DIA with conventional methods, this review discusses reproducibility, application of stereology-based quantitative measurements, time consumption, optimization of histological slides, regions of interest selection and recent developments in staining and imaging techniques.