Myelofibrosis

Primary myelofibrosis starts on its own. Secondary myelofibrosis develops in someone who already has polycythemia vera (post-PV myelofibrosis) or essential thrombocythemia (post-ET myelofibrosis). NCI describes this later stage as a "spent phase" that looks like primary myelofibrosis, with low blood counts and scarring in the marrow. Treatment is much the same. For example, NCI notes that ruxolitinib helps in both. Doctors use different risk scores, though: DIPSS or MIPSS70 for primary myelofibrosis, and MYSEC-PM for secondary myelofibrosis.

Yes, in a minority of people, usually after many years. A 2015 review of published studies found reported rates of 6% to 14% within 15 years for polycythemia vera, and 4% to 11% within 15 years for essential thrombocythemia. The studies used different methods, so these ranges are rough. Reported warning signs include older age, a high white-cell count and early scarring in the marrow. Having them does not mean it will happen.

It varies widely, from a few years to well over 10 years. For primary myelofibrosis, NCI summarizes warning features that help estimate outlook. They are age 65 or older, low hemoglobin, fever, night sweats or weight loss, a high white-cell count, and blasts in the blood. The more of these a person has, the shorter survival tends to be. Very low platelets also point to a harder course, in both primary and secondary myelofibrosis. The outlook section on this page gives the figures, with the groups they describe.

Sometimes. NCI and European transplant recommendations both say a donor stem cell transplant (allogeneic transplant) is the only treatment that may cure it. The transplant carries serious risks, including death, so it is mainly used for people with higher-risk disease who are fit enough. Other treatments help in different ways. Medicines such as ruxolitinib, a JAK inhibitor, can shrink the spleen and ease tiredness, night sweats and weight loss. Transfusions and other medicines can treat anemia.

Usually not. The gene changes linked to it, most often in the JAK2, CALR or MPL genes, happen in blood-forming cells during a person's life. NCI notes that these blood cancers usually happen sporadically, meaning by chance. A few families have more than one person with one of these conditions, but that is uncommon.

Often early. Guidelines from NMDP and the American Society for Transplantation and Cellular Therapy (ASTCT) recommend detailed tissue typing (HLA typing) and a transplant consultation at diagnosis for many people with myelofibrosis. This includes people with intermediate-1 or higher DIPSS scores, intermediate or higher MIPSS70 scores, high-risk gene changes, low blood counts (the cytopenic subtype) or young age. It also includes people whose JAK inhibitor has stopped working. A consultation does not mean a transplant will happen. It gives the team time to plan.