Chemotherapy is one of the most successful ways of treating cancer, but cancer can spread through chemotherapy in some cases. such as advanced cancers, which can move to other tissues and lymph nodes locally.

Advanced cancers can also metastasize to other organs, because they are among the hardest cancers to treat, so chemotherapy may not help to shrink or treat advanced or metastasized cancers.

Also, there are some types of cancer that can spread during chemotherapy, because they have mutated to resist chemotherapy, or the cells that surround the tumor cells respond incorrectly to the chemotherapy and release some chemicals that can protect the tumor cells from it.