What Happens If Platelets Are Low in Cancer Patients?

Low platelet symptoms may include bleeding, blood in stool, blood in vomit or saliva, blood in urine, heavy periods, red pinpoint dots on the skin, severe headaches/dizziness/blurred vision, weakness, and others.

Platelets are blood cells that help the blood to clot so bleeding stops. A low platelet count (thrombocytopenia) means the body will be unable to clot properly, and excessive bleeding may occur.

If platelet levels are low in cancer patients (and in people who don’t have cancer), symptoms may occur such as: 

• Bleeding 
• Blood in stool 
  • The stool may appear bright red, dark red, or black 
• Blood in vomit or saliva
  • Saliva or vomit may appear dark brown 
• Blood in urine
  • Urine may have a red, pink, or brown color
• Heavy vaginal bleeding during periods 
• Red pinpoint dots on the skin that often begin on the feet and legs
• New and unexplained bruising on the skin
• Severe headaches, dizziness, or blurred vision
• Weakness that gets worse
• Pain in joints or muscles

Contact your doctor or cancer care team immediately if you notice any symptoms of low platelets. An oncologist may delay treatment or reduce the dosage of some medications so platelet levels have a chance to increase.

Platelets may be low if: 

• The body does not produce enough platelets
• Platelets are being lost
• Platelets are being destroyed

In cancer patients, low platelets may be caused by:

• Certain types of cancer
  • Some cancers can lower platelet count 
    • Lymphomas 
    • Leukemias 
• Certain types of cancer treatment
  • Chemotherapy 
  • Radiation therapy 
    • Doesn’t usually cause low platelets but low platelets may occur with high doses of radiation to the pelvis or with radiation therapy used with chemotherapy at the same time (chemoradiation)
• Antibodies 
  • Antibodies are proteins produced in the body that usually attack foreign, harmful invaders such as viruses and bacteria
  • Sometimes antibodies are produced that can attack and destroy platelets
• Another health problem or medication not related to the cancer
• Less common causes of low platelets may include:
  • Cancer that spreads (metastasizes) to the bone
  • Cancer in the spleen

Low platelets in cancer patients are diagnosed with a blood test called a complete blood count (CBC) that measures platelet levels along with other blood markers. 

Managing low platelets in cancer patients is a part of a treatment called palliative care or supportive care. 

• When platelet counts are very low, a transfusion of platelet cells may be administered 
  • This may help prevent heavy or unusual bleeding
  • This is a temporary treatment and the platelets only last about three days
• During chemotherapy
  • If patients have low platelet counts, the oncologist may adjust the treatment
  • Chemotherapy doses may be reduced or patients may wait longer between treatments
  • Oprelvekin (Neumega) may be prescribed to help prevent an extremely low platelet count
• Before surgery
  • If surgery is needed and patients have low platelets, surgery may need to be postponed until platelet counts return to normal to lower the risk of heavy bleeding