Simple blood count foretells survival in aggressive skin cancer

Something as simple and routine as a white blood cell count could reveal survival chances in a rare but aggressive form of skin cancer known as Merkel cell carcinoma, which tends to attack people with weakened immune systems. The findings, from researchers at Fox Chase Cancer Center, were presented at the American Society for Radiation Oncology's 54th Annual Meeting.

The team screened 64 patients treated between 1992 and 2010. Half of the patients who had an absolute lymphocyte count (ALC) below 1500 cells per cubic millimeter of blood survived for only 25 months or less after treatment. In stark contrast, half of the patients with normal ALCs survived for 97 months or more after treatment. After 60 months, 67% of patients with higher counts were still disease-free, compared with just 24% of those with the lower ALCs.

"Since ALC has been tied to prognosis in other types of cancer, we were expecting to see some difference between patients with high and low counts," says lead author Matthew Johnson. "But it was definitely a bigger difference than what we were anticipating."

This difference may be because higher counts of lymphocytes indicate a healthier immune system, which could be keeping the cancer in check. Because Merkel cell carcinoma is so fast-growing, it can be hard to predict how long a patient might survive. ALC is already commonly carried out in workups of patients with Merkel cell carcinoma and could be a simple way of giving patients at least some idea of their outcomes, which is important information for some.

- read the press release
- see the abstract