The female superiority in survival in clinical stage II cutaneous malignant melanoma.

Five-year survival rates were similar in men and women with nodal metastases from malignant melanoma (clinical Stage II). This is in contrast to our previous studies on patients with localized disease (clinical Stage I) which indicated a marked female superiority in survival. To seek explanation for this, we examined in these patients with regional lymph node metastases, four factors which we previously showed to be of prognostic importance in patients with localized disease: (1) Age of patient: overall survival rate in Stage II women was markedly reduced due to extremely poor prognosis for postmenopausal women; (2) Site of primary lesion: Stage II women had a preponderance of extremity lesions, but these were not more prognostically favorable anatomic locations than axial locations; (3) Tumor thickness: women with metastatic malignant melanoma had a significantly higher proportion of very thick lesions than men; and (4) Evidence of tumor regression: although men with very thin regressing tumors had a poor prognosis, there were too few lesions of this thickness in patients with Stage II melanoma to markedly influence overall survival. It was concluded that although overall five-year survival rates in men and women with clinical Stage II malignant melanoma were similar, if these patients were matched by age and thickness of primary lesion, a female superiority in survival did exist for young patients with very thick tumors.

Cutaneous malignant melanoma: occupational and prognosis.

In Queensland and New South Wales, malignant melanoma is being diagnosed and treated at an earlier biological stage than in previous years. An analysis of 670 men treated since 1973 at Sydney Hospital indicated that recognition of and survival from melanoma varied according to occupation. Unskilled patients had a markedly worse prognosis than more skilled patients, a finding attributable, at least in part, to later presentation for treatment. We conclude that although public awareness of melanoma has increased due to continual publicity, the educational programme must be concentrated on the lower socioeconomic groups.

Malignant melanoma: influence of site of lesion and age of patient in the female superiority in survival.

Efforts were made to further explain female superiority in survival of 753 patients with clinical Stage I malignant melanoma. Two factors contributing to this female superiority in survival drew some of their prognostic value from the correlation with tumor thickness. (1) More than twice as many women as men had primary lesions located on the extremities, which were prognostically favorable anatomical sites in both men and women. In addition, women with extremity lesions had a more favorable prognosis than men with extremity lesions. This sex differential in survival for patients with extremity lesions was partly attributable to the fact that the extremity lesions of women were significantly thinner than those of men. (2) Significantly more women than men were under age 50; this age group of women had a significantly better prognosis than the corresponding age group of men. The sex differential in survival for patients under 50 years was partly attributable to the fact that the women's lesions were significantly thinner than those of men. There was only a slight sex differential in the survival of patients 50 years and over, a finding in consonance with the smaller difference in tumor thickness between these older men and women. The association between decline in prognosis with increasing age and decline in proportion of thin lesions with increasing age was much closer in men than women. In men and women matched by age, site, and thickness of primary lesions, women with very thick tumors still survived longer.

Tumour thickness and the site and time of first recurrence in cutaneous malignant melanoma (stage I).

A study was made of 326 patients first treated for clinical stage I cutaneous malignant melanoma by a wide excision (with or without split-skin graft) but no nodal dissection and who subsequently developed recurrence of their disease. Thick lesions recurred far more frequently than very thin lesions, although evidence of partial regression in very thin lesions conferred upon the latter a liability to metastasize. Thicker lesions first recurred predominantly in the vicinity of the scar of primary lesion excision whilst very thin lesions first recurred either at regional lymph nodes or at remote sites. The disease-free interval fell with increasing tumour thickness. As a result of this, local first recurrences developed more rapidly than remote first recurrences. The cumulative 10-year survival rate for patients with local first recurrences was, however, significantly higher than for patients with remote first recurrences, as the survival period after local first recurrence was considerably longer than after remote first recurrence. We conclude that tumour thickness is an easily measured, objective predictor of the site and time of first recurrence from melanoma. Thus, by facilitating early detection of first metastases, it may be possible to prolong survival time.

Is malignant melanoma arising in a Hutchinson's melanotic freckle a separate disease entity?

Several features which distinguish malignant melanoma arising in a Hutchinson's melanotic freckle (HMFM) from other types of malignant melanoma (MM) are described. Forty-eight patients with HMFM of the head and neck region were compared with 98 patients with MM of the head and neck region. All patients were clinical stage I. There was a preponderance of women amongst HMFM patients but not MM patients and HMFM patients were significantly older than MM patients. Although HMFM patients had thicker tumours than MM patients, these thicker lesions had a lower degree of mitotic activity and a higher incidence of partial regression. Overall prognosis for HMFM patients was significantly better than for MM patients, this being particularly so for women, none of whom died of melanoma. There was no close correlation between prognosis of HMFM patients and the thickness of their tumours. Every one of the HMFM in this study displayed evidence of severe solar degeneration, but such degeneration per se did not appear to confer upon these lesions their benign biological behaviour.

Histologic features of tumors and the female superiority in survival from malignant melanoma.

The primary tumors of 780 patients with clinical Stage I malignant melanoma were reviewed to seek reasons for the female superiority in survival. Histologic features of tumors believed to be of prognostic significance were examined: tumor thickness, evidence of regression, histogenetic type, and mitotic activity. The average tumor thickness was significantly less in women, due to a preponderance of very thin lesions in women and very thick lesions in men. In both men and women, there proved to be a direct correlation between five-year survival rate and tumor thickness, but women had a higher survival rate than men at each thickness level. These latter two findings, in combination, could contribute to the overall female superiority in survival. No further insight into the sex difference in survival was obtained from the examination of the other histologic features. Although the incidence of partial lesion regression was not markedly different except for very thin lesions. There were no disparities between the sexes in the incidences of histogenetic types or grades of mitotic activity, two histologic features which drew their prognostic significance only from their correlation with tumor thickness.

Prognostic significance of the histological features of malignant melanoma.

A review of 694 patients with localized cutaneous malignant melanoma (clinical stage I) revealed that three histological features of the primary lesion had no effect of their own on survival rate but derived their prognostic significance only because of their close correlation with tumour thickness. Primary lesions of superficial spreading histogenetic type, or of low mitotic activity or showing evidence of partial regression appeared to have a more favourable prognosis than lesions of nodular histogenetic type or of high mitotic activity or showing no regression. However, the former three histological features were predominant in thin lesions which had a better prognosis than thicker lesions. It was concluded that these features exerted only an indirect effect upon survival, tumour thickness being the most important prognostic determinant.

Effect of smoking on the recurrence of malignant melanoma.

Smoking has been recently shown to lead to aberrant immunological function in man. Since immunological host resistance is important in the natural history of human malignant melanoma, it was the object of this study to determine the effects of smoking on the course of this disease. Investigations on 1908 patients with malignant melanoma indicated that smoking renders men significantly more susceptible to developing metastases. The proportion of men smokers free of disease five years after melanoma diagnosis was significantly lower than that of men non-smokers. An effect of smoking similar to that recorded in men was not evident in women with malignant melanoma.