Melanoma Breslow Thickness Research Articles

Cutaneous melanoma in Caucasian New Zealanders: 1995-1999.

The aim of the present study was to evaluate the spectrum of cutaneous melanoma in Caucasian New Zealanders. Data were obtained from the New Zealand Cancer Registry by way of a computerized search of the melanoma ICD-9 codes from 1995 to 1999. The final database used is for people identifying themselves as European. The denominator population were people stating their ethnicity as European in the 1996 New Zealand Census; all others were excluded. The Cancer Registry Act 1993 made reporting of cancer mandatory. Cancer data before July 1994 are of dubious accuracy. There were 4966 cases of cutaneous melanoma reported in New Zealand between 1995 and 1999 by people identifying themselves as European. The trends and statistically relevant findings will be discussed. New Zealand continues to have one of the highest rates of melanoma in the world, with an increasing Breslow thickness of melanoma (P < 0.001) over the 5-year period. Men have a higher rate and deeper melanomas than women (P < 0.001). The incidence of melanoma appears to have reached a plateau over the review period. The far north of New Zealand (Whangarei and further north) had the highest rate of melanoma in New Zealand (59.1/100000, age standardized) and the lowest rate is in Southland (23.5/100000).

Sentinel lymph node biopsy for melanoma: how many radioactive nodes should be removed?

Sentinel lymph node (SLN) biopsy has become a standard method of staging patients with cutaneous melanoma. Sentinel lymph node biopsy usually is performed by intradermal injection of a vital blue dye (isosulfan blue) plus radioactive colloid (technetium sulfur colloid) around the site of the tumor. Intraoperative gamma probe detection has been shown to improve the rate of SLN identification compared to the use of blue dye alone. However, multiple sentinel nodes often are detected using the gamma probe. It is not clear whether these additional lymph nodes represent true sentinel nodes, or second-echelon lymph nodes that have received radiocolloid particles that have passed through the true sentinel node. This analysis was performed to determine the frequency with which these less radioactive lymph nodes contain metastatic disease when the most radioactive, or "hottest," node does not. In the Sunbelt Melanoma Trial, 1184 patients with cutaneous melanoma of Breslow thickness 1.0 mm or more had sentinel lymph nodes identified. Sentinel lymph node biopsy was performed by injection of technetium sulfur colloid plus isosulfan blue dye in 99% of cases. Intraoperative determination of the degree of radioactivity of sentinel nodes (ex vivo) was measured, as well as the degree of blue dye staining. Sentinel nodes were identified in 1373 nodal basins in 1184 patients. A total of 288 of 1184 patients (24.3%) were found to have sentinel node metastases detected by histology or immunohistochemistry. Nodal metastases were detected in 306 nodal basins in these 288 patients. There were 175 nodal basins from 170 patients in which at least one positive sentinel node was found and more than one sentinel node was harvested. Blue dye staining was found in 86.3% of the histologically positive sentinel nodes and 66.4% of the negative sentinel nodes. In 40 of 306 positive nodal basins (13.1%), the most radioactive sentinel node was negative for tumor when another, less radioactive, sentinel node was positive for tumor. In 20 of 40 cases (50%), the less radioactive positive sentinel node contained 50% or less of the radioactive count of the hottest lymph node. The cervical lymph node basin was associated with an increased likelihood of finding a positive sentinel node other than the hottest node. If only the most radioactive sentinel node in each basin had been removed, 13.1% of the nodal basins with positive sentinel nodes would have been missed. It is recommended that all blue lymph nodes and all nodes that measure 10% or higher of the ex vivo radioactive count of the hottest sentinel node should be harvested for optimal detection of nodal metastases.

Breslow thickness of melanoma in the region of Romagna, Italy

Breslow thickness of melanoma in the region of Romagna, Italy

Breslow thickness of melanoma can be measured in frozen sections

Breslow thickness of melanoma can be measured in frozen sections

High counts of normal melanocytic naevi are a risk factor for cutaneous malignant melanoma

We have carried out a case control study on 200 patients presenting in the past 3 years with primary cutaneous malignant melanoma and 200 age‐ and sex‐matched controls. Total body melanocytic naevus counts were performed on all 400 subjects by four trained dermatologists. Analysis was by stratum matched logistic regression, with stratum matching for age, sex and city of treatment. Each variable was adjusted for the other risk factors found in the study, such as hair and eye colour, skin type, amount of UV exposure and episodes of acute sunburn. Substantially increased risk of malignant melanoma was found for persons with large numbers of normal benign melanocytic naevi, with any moles larger than 7 mm in diameter, and also with irregular edges and colour variation in moles—the so‐called dysplastic naevi. The number of moles present on the same anatomical areas as the tumour (arms, legs, trunk, face, head and neck, and palms and soles) was a stronger predictor of melanoma incidence than was the total number of body moles. The relationship of histology and Breslow thickness of melanoma to site, sex, age and number of naevi will also be presented. Our results show that a very high‐risk group for melanoma can now be identified and these patients should be advised about avoiding excessive sun exposure and the early recognition of cutaneous melanoma.