Which of the following can contribute to chemotherapy resistance?

Altering metabolic pathways significantly contributes to chemotherapy resistance. Cancer cells can adapt to the presence of chemotherapy drugs by modifying their metabolic processes. For instance, some tumors may enhance their energy production through alternative pathways, allowing them to thrive even in the presence of chemotherapeutic agents designed to kill them. Additionally, changes in the way cancer cells process nutrients can lead to reduced effectiveness of the drugs, as these cells may manipulate their metabolism to evade the cytotoxic effects of the treatment.

Other factors such as increased patient weight, improved patient compliance, and higher doses of chemotherapy are less directly related to the mechanisms underlying chemotherapy resistance. Increased patient weight might affect drug dosing or distribution but does not directly influence the resistance mechanisms. Improved patient compliance is generally associated with better treatment outcomes, while higher doses of chemotherapy don't inherently contribute to resistance but may lead to increased toxicity without necessarily overcoming the cancer's inherent resistance mechanisms.