This large series documents the characteristics of patients who developed cerebral metastases from melanoma. Median survival was dependent on treatment, which in turn was dependent on patient selection.

BACKGROUNDThe current study was performed to determine whether tumor mitotic rate (TMR) is a useful, independent prognostic factor in patients with localized cutaneous melanoma.METHODSFrom the Sydney Melanoma Unit database, 3661 patients with complete clinical information and details of primary tumor thickness, ulcerative state, and TMR were studied. TMR was expressed as mitoses per mm2 in the dermal part of the tumor in which most mitoses were seen, as recommended in the 1982 revision of the 1972 Sydney classification of malignant melanoma. To determine which was the more prognostically useful method of grouping TMR, two separate methods (A and B) were used. Factors predicting melanoma‐specific survival were analyzed using the Cox proportional hazards regression model.RESULTSPatients with a TMR of 0 mitoses/mm2 had a significantly better survival than those with 1 mitosis/mm2 (P < 0.0001) but no significant survival differences were recorded for the stepwise increases from 1–2, 2–3, 3–4, and 4–5/mm2. Tumor thickness, ulceration, and TMR were closely correlated, whether TMR was grouped using Method A (0, 1–4, 5–10, and ≥ 11 mitoses/mm2) or Method B (0–1, 2–4, and ≥ 5 mitoses/mm2). However, Cox regression analysis indicated that the TMR was a highly significant independent prognostic factor, particularly when grouped according to Method A, in which it was second only to tumor thickness as the most powerful predictor of survival (P < 0.0001).CONCLUSIONSTMR is an important independent predictor of survival for melanoma patients. If confirmed by studies from other centers, it has the potential to further improve the accuracy of melanoma staging, as well as to define more rigidly the risk categories for patients entering clinical trials. Cancer 2003;97:1488–98. © 2003 American Cancer Society.DOI 10.1002/cncr.11196

TMR was confirmed to be an important independent predictor of survival of patients with primary cutaneous melanoma. However, its predictive value was less than it was when assessed according to the 1982 revisions of the 1972 TMR recommendations.

Appropriately trained and experienced histopathologists can assess prognostically important features of melanomas accurately and reproducibly. Given our recent finding of the significance of TMR in determining prognosis, it is important that this feature be assessed by a standardized method and documented for all primary cutaneous melanomas.