Question: Dear Doctor,

My father-in-law is currently undergoing chemotherapy for colon cancer. He supposed to do 8 cycles of Capecitabine and currently on cycle 6. The Oncologist's summary of his colon tumor surgery (last November) attached. The oncologist has been reducing his drugs and also extend the rest period (now 2 weeks in between cycles) due to his reaction to chemo which including feet sore/burning, skin darkening, tongue blisters, loose stool (not to the level of diarrhea yet), dry/cracking skin on hands... In the most recent visit (post cycle 5), the doctor suggested him to take 10 days and skip the last 2 days if he doesn't feel good, and somewhat also mentioned that he can even perhaps skip the next 2 cycles if he wants. I attached his blood test results after the cycle 4 and cycle 5.

After consulting Dr. Ditah from your website and also seeing the family doctor today, we understand his blood test results didn't show anything significantly concerning.

However, my father feels that now it is left to his own discretion on how far to go, i.e. whether to complete this current cycle or continue with his remaining 2 cycles. But he feels that he doesn't have much judgement himself to make a decision. Even though he has a lot of side effects, nothing is totally unbearable to him. So we have the following question and hope you could help. We will for sure discuss with his Oncologist in the next visit (post cycle 6) but we have to get some sense ourselves.

- if attacked by capecitabine, can a cancer cell be killed in a cycle (i.e. within 12 days of using the drug) or 8 cycles are needed to fully kill a cancer cell? we just want to make sure if he chose to stop at cycle 6, all the effort over the past 4 months' chemo won't be wasted.
- if he can tolerate (assuming he has high tolerance of discomfort), is it in his best interest to complete the 8 cycles in order to kill as many cancer cells as possible? i.e. lower the potential cancel occurrence to as low as possible...
- is 1000mg of Capecitabine the minimum to ensure effective? we hope to understand why his oncologist didn't further reduce his dosage but rather suggest him to do a shorter cycle, ie. 10 day instead of 12 days...

Thanks a lot!
XXXX