SEER is an authoritative source of information on cancer incidence and survival in the United States. SEER currently collects and publishes cancer incidence and survival data from population-based cancer registries covering approximately 30 percent of the U.S. population.
Most ALL patients present with widespread lymph node involvement as well as peripheral blood involvement. The number of circulating neoplastic cells does not correlate with the degree of bone marrow involvement, suggesting that circulating cells are recruited from other organs such as the skin. In fact, the skin is the most common extra-lymphatic site of involvement.