Which alteration in drug resistance involves changes to drug receptor sites?

Alterations in drug resistance that involve changes to drug receptor sites typically refer to structural changes in the receptors that drugs target. When the structure of these receptor sites is modified, the binding affinity of the drug to its target can be significantly reduced, which means that the drug is less effective in exerting its intended therapeutic effect. This can occur through various ways, such as mutations in the genes encoding the receptors or changes in post-translational modifications. As a result, even in the presence of the drug, the cancer cells may be able to evade its effects due to the diminished interaction between the drug and its receptor.

In contrast, decreased drug uptake refers to the reduced ability of the drug to enter the cell, while detoxification involve mechanisms within the cell that modify or neutralize the drugs after they have entered. Increased sensitivity to apoptosis suggests that the cell may be more likely to undergo programmed cell death, which is unrelated to receptor alterations and could benefit from standard therapeutic approaches. These other choices do not involve the specific mechanism of changes to drug receptor sites that is central to the correct answer.