A complete duration of chemotherapy treatment is made up of several cycles. This treatment is usually administered in cycles. By cycles it means that the medicine is given for a specific time period, this treatment period is followed by a period of recovery with no treatment. One variation of a cycle may be that a patient is given chemotherapy on the first day of the cycle and then stopped for a few weeks with no treatment of recovery. This would make one cycle. Another variation may be when chemotherapy is administered for several days continuously, or alternatively every consequent day, and then treatment stopped for the recovery period. These several cycles which make up a chemotherapy regimen vary in each regimen and even the total time of each regimen depends on the medicines used in the chemotherapy. Predominantly the regimens range from a 3 month to a 6 month duration. Thus a chemotherapy treatment schedule varies from patient to patient as per the medication used.
A “dose dense” chemotherapy schedule is recommended in certain cases, especially for cancer with high recurrence risk. It implies that the dosage is timed at 2 weeks instead of being given every three weeks – the more routine schedule. Studies have shown that dose dense therapy improves upon the survival rate and reduces cancer recurrence risk when compared to a traditional chemotherapy regimen.
The recovery period is reduced in a dose-dense chemotherapy and between chemotherapy cycles and as such there is less time for the immune system and red blood cells for recovery. Thus in dose dense therapy to strengthen the immune system medicines Neupogen (chemical name: filgrastim) or Neulasta (chemical name: pegfilgrastim) are used and similarly to keep the red blood cell system robust medicines Procrit (chemical name: epoetin alfa), Epogen (chemical name: epoetin alfa), or Aranesp (chemical name: darbepoetin alfa) are used during dose-dense chemotherapy.