I've been taking apatinib for 4 days; will the tumor shrink?

After taking apatinib for 4 days, tumors typically do not show obvious shrinkage, and significant changes in tumor size are unlikely to be observed in such a short period. The detailed explanation is as follows:

Apatinib is a small-molecule anti-angiogenic drug that works by inhibiting the formation of tumor blood vessels, thereby cutting off the nutrient supply to the tumor and suppressing its growth. This mechanism does not produce immediate effects; rather, it takes time for the drug to gradually impair the tumor's blood supply and subsequently inhibit tumor growth. Tumor cell proliferation and metabolism follow their own biological cycles. After the drug takes effect, reduction in tumor volume requires a gradual process involving vessel atrophy and slow tumor cell death due to nutrient deprivation. This process usually takes several weeks or even months, so 4 days of treatment is far too short to result in noticeable tumor shrinkage.

In the initial phase of apatinib treatment, some patients may experience drug-related adverse reactions such as hypertension, hand-foot syndrome, or proteinuria. However, these side effects are not directly correlated with tumor shrinkage. To determine whether the tumor is responding to apatinib, imaging evaluations must be performed according to the prescribed treatment schedule under medical supervision, comparing tumor size before and after treatment to assess therapeutic efficacy.

Therefore, there is no need to rush to judge tumor response after only 4 days of apatinib treatment. Patients should continue taking the medication as prescribed, closely monitor any adverse effects, promptly communicate with their physicians, and wait until the designated evaluation time point to undergo professional assessments for definitive evaluation of treatment outcomes.