My plasma fibrinogen is less than 0.5g/l which is really low. mum has dysfibrinogenaemia but i'm wondering if low fibrinogen can be caused by cancer?

No: Cancer does not cause low plasma fibrinogen. It would be good idea to see a doctor for a complete evaluation. For good health - Have a diet rich in fresh vegetables, fruits, whole grains, milk and milk products, nuts, beans, legumes, lentils and small amounts of lean meats. Avoid saturated fats. Exercise at least 150 minutes/week and increase the intensity of exercise gradually. Do not use tobacco, alcohol, weed or street drugs in any form. Practice safe sex. Get HPV vaccine.