Order of treatment

Duke….this is what I have learned. Chemo attacks the cells at a particular stage.

The cell cycle is important because many chemotherapy drugs work only on cells that are
actively reproducing (not cells that are in the resting phase, G0). Some drugs specifically
attack cells in a particular phase of the cell cycle (the M or S phases, for example).
Understanding how these drugs work helps oncologists predict which drugs are likely to
work well together. Doctors can also plan how often doses of each drug should be given
based on the timing of the cell phases.
Chemotherapy drugs cannot tell the difference between reproducing cells of normal
tissues (those that are replacing worn-out normal cells) and cancer cells. This means
normal cells are damaged and this results in side effects. Each time chemotherapy is
given, it involves trying to find a balance between destroying the cancer cells (in order to
cure or control the disease) and sparing the normal cells (to lessen unwanted side effects).

The Cell Cycle
G0 phase (resting stage): The cell has not yet started to divide. Cells spend much
of their lives in this phase. Depending on the type of cell, G0 can last from a few
hours to a few years. When the cell gets a signal to reproduce, it moves into the
G1 phase.
G1 phase: During this phase, the cell starts making more proteins and growing
larger, so the new cells will be of normal size. This phase lasts about 18 to 30
hours.
S phase: In the S phase, the chromosomes containing the genetic code (DNA) are
copied so that both of the new cells formed will have matching strands of DNA.
The S phase lasts about 18 to 20 hours.
G2 phase: In the G2 phase, the cell checks the DNA and gets ready to start
splitting into 2 cells. This phase lasts from 2 to 10 hours.
M phase (mitosis): In this phase, which lasts only 30 to 60 minutes, the cell actually splits into 2 new cells.
Source: cancer/org