NO IMPROVEMENT IN SURVIVAL FROM MELANOMA DIAGNOSED FROM 1973 TO 1984

Background. While the incidence and mortality of melanoma has increase d dramatically during the last few decades, survival rates, based on t he case-fatality ratio, have apparently improved. Efforts at early det ection have probably been effective in the discovery of lesions at a c urable stage. However, the effects of lead-time bias need to be accoun ted for in order to understand the contribution of early detection to the increased incidence. This can best be done by appropriately contro lling for depth of the tumour or a surrogate of depth, at diagnosis. M ethods. A survival analysis was conducted for 3197 Connecticut residen ts newly diagnosed with invasive melanoma between 1973 and 1984. Five prognostic variables were evaluated: sex, age at diagnosis, anatomical site, histological type, and year of diagnosis. Results. As expected, women and the young had better survival than men and the elderly. Mel anomas located on the trunk had poorer prognosis than those on other s ites. The survival experience by histological type was significantly d ifferent; lentigo maligna melanoma and superficial spreading melanoma had the best survival and nodular melanomas the poorest, while 'other' and unclassifiable melanomas had intermediate survival. When survival by period of diagnosis was controlled by other variables, which inclu ded surrogates for disease stage, there was no improvement in survival over time. Conclusion. These data do not imply that early diagnosis a nd treatment are ineffective; rather, that within stages of disease, s urvival improvements did not occur during the period 1973-1984.