| Why does breast cancer make platelet counts | | | | response, with the lowest platelet counts (called |
| drop? | | | | the nadir) usually occurring seven to 14 days |
| In most cases, it's not the breast cancer itself but | | | | after chemo. After that, the body begins |
| the breast cancer treatment that causes low | | | | regenerating platelets at a rate of approximately |
| platelets. Chemotherapy can make platelet counts | | | | 10 percent a day. (Platelets have a life span of |
| fall because it targets cells that grow rapidly. | | | | eight to ten days, so, on any given day, |
| Tumor cells grow and divide quickly, but so do the | | | | approximately 10 percent are being lost and |
| cells in the bone marrow that produce red blood | | | | replaced.) But some types of cancer and some |
| cells and platelets. Radiation can also cause a low | | | | types of treatment suppress the production of |
| platelet count, also called thrombocytopenia, | | | | platelets, so the rebuilding process can be much |
| though this is uncommon with radiation to the | | | | slower. |
| areas near the breast. | | | | How low does platelet count need to go before |
| Can low platelet counts be prevented? | | | | treatment is necessary? |
| There are medications called cell growth factors | | | | The answer to this question, in most cases, |
| that can be given along with chemo or radiation | | | | depends on whether there are bleeding problems, |
| to prevent blood counts from dropping. The | | | | because most doctors will treat the symptoms |
| growth factor that works for low platelets is | | | | rather than looking only at the platelet count. A |
| called oprelvekin (brand name Neumega). There's | | | | normal platelet count is between 150,000 and |
| a risk of side effects with this medication, though, | | | | 450,000 per cubic millimeter, but most people |
| so the doctor will decide whether to prescribe it | | | | won't experience serious bleeding problems until |
| based on her assessment of the risk of | | | | their platelet count drops below 50,000, and some |
| developing a low platelet count. The doctor will | | | | will function fine with a platelet count lower than |
| also consider any possible heart problems, | | | | that. "Doctors try not to treat to a number |
| because Neumega's side effects include fluid | | | | because everyone is different and reacts |
| retention and heart palpitations -- both of which | | | | differently," says Andrew Putnam, director of the |
| can worsen heart conditions. Other side effects | | | | Palliative Care program at Lombardi |
| include diarrhea and other digestive issues. | | | | Comprehensive Cancer Center and Georgetown |
| How long will it take platelet counts to rise again? | | | | University. "If the patient isn't having problems |
| That's the big question, and the answer is: | | | | with bleeding, then the doctor will probably let it |
| probably within three to four weeks. Doctors can't | | | | go lower and see if the counts recover." |
| make an accurate prediction because platelet | | | | What symptoms of low platelet count should I |
| count depends on many factors, including the | | | | watch for? |
| type of treatment -- particularly the type and | | | | Bruising and bleeding that won't stop are the two |
| dosage of chemo -- and a patient's general state | | | | main signs of a low platelet count. Watch, too, for |
| of health. One thing to keep in mind is that platelet | | | | frequent nosebleeds or a nosebleed that won't |
| counts generally won't drop immediately after | | | | stop. Women who are still menstruating need to |
| chemo; it usually takes a week or two. This is | | | | watch out for heavy flow that seems like it won't |
| because chemo doesn't kill off the platelets | | | | let up. Less common symptoms of a low platelet |
| already in the bloodstream, which are mature and | | | | count are blood in the stool or black, tarlike |
| aren't dividing rapidly. It kills off the cells forming in | | | | stools;blood in the urine; or a skin rash of |
| the marrow, and therefore there's a delayed | | | | pinprick-size red dots. |