What happens to a tumor if chemo sessions are skipped?

Velina asked...

I would like to know what happens to a tumor when a patient misses their scheduled chemo cycles a few weeks in a row. Does the tumor start growing again?

Expert Answer

Andrew Putnam, M.D. is a Palliative Care physician at Smilow Cancer Center at Yale New Haven Hospital and Yale University.

What will happen to a tumor if chemo sessions are skipped depends on the effect of the chemo on the tumor. Sometimes a specific chemotherapy does not work against a tumor and so the tumor just continues to grow without the chemo. If the chemo is effective against the tumor, then it is possible the the tumor might start to grow again if there were no chemo for some time. If a chemo is effective against a tumor, it is generally best to continue the chemotherapy according to oncologist's protocol as long as it is safe for the patient. At times though, the patient may be very weak or sick. At those times it may be that the safest thing for the patient is too stop the chemotherapy for a while. There are times when it is necessary to stop the chemotherapy for the good of the patient even though the tumor may grow.