Patients with severe muscular dystropy have increased risk of developing cancer
14 December 2011
Compared with the general population, patients with the disease myotonic muscular dystrophy (MMD; a form of muscular dystrophy characterised by neuromuscular disorder, attacking face, feet, hands and neck) have an increased risk of developing cancer, particularly of the brain, ovaries, colon, and uterus. However, also the risk of cancer in other organs seems increased.
Sensational findings
These remarkable findings are published today in the renowned American journal JAMA. The findings are a result of a collaboration between researchers at Statens Serum Institut, Copenhagen, and researchers at the National Cancer Institute, USA.
Rare for a disease to be associated with several different forms of cancer
'Our findings are of importance to the clinical follow-up of MMD patients and not least, it is crucial to focus on the symptoms of this group of patients which may be the first signs of cancer development. It is quite rare to be faced with a disease which in this case appears to be associated with several different forms of cancer. By studying the background to this increased risk, we can obtain new valuable information on the reasons why cancer diseases occur', says Professor Mads Melbye.
Register-based study
What gave the researchers the idea for the study were single observations indicating that patients with this illness in certain cases also had malignant or benign tumors.
The researchers took advantage of the unique Danish and Swedish registers to investigate the association between MMD and cancer. In total, 1,658 patients with the relatively rare disease MMD were identified in the period 1977 and 2008. These persons' cancer development was compared with that of the general population by data extracts from the Danish and Swedish cancer registers. In both countries, approximately half of the patients were males, 40 percent died in the follow-up period, and 6 percent developed cancer. The patients were followed from the day of MMD diagnosis until first cancer diagnosis, death, emigration, or end of 2008.
Increased number of cases of certain cancer forms
In the follow-up period, 104 MMD patients developed cancer, while 52 cases were expected based on follow-up of the general population. This difference was statistically significant. The incidence of certain cancer forms was particulary increased among MMD patients, such as cancer of the uterus (7.6 times), brain (5.3 times), ovaries (5.2 times) and colon (2.9 times). Men and women had the same increased risk.
Read the scientific article
Gadalla SM, Lund M, Pfeiffer RM, Gørtz S, Mueller CM, Moxley RT, Kristinsson SY, Björkholm M, Shebl FM, Hilbert JE, Landgren O, Wohlfahrt J, Melbye M, Greene MH. Cancer risk among patients with myotonic muscular dystrophy. JAMA 2011;306:2480-2486