Which of the following is true about Tamoxifen?

Tamoxifen is primarily recognized for its role in treating estrogen-receptor positive tumors, particularly breast cancer. This medication functions as a selective estrogen receptor modulator (SERM), which means it can block the effects of estrogen in certain tissues, such as breast tissue, where estrogen can promote tumor growth. By inhibiting estrogen's action, Tamoxifen helps reduce the risk of cancer recurrence in patients whose tumors are responsive to estrogen.

The importance of targeting estrogen-receptor positive tumors lies in the fact that these types of cancers often rely on estrogen for growth. Therefore, the use of Tamoxifen is particularly effective in these cases, making it a pivotal treatment in managing certain forms of breast cancer. This targeted approach enhances treatment efficacy and improves patient outcomes.

The other options do not accurately represent the primary indications and effects of Tamoxifen. For instance, it is not associated with causing kidney damage in patients; its side effects mainly revolve around hormonal variations and risks such as an increased chance of endometrial cancer. While some patients may experience weight changes, the notion that it promotes significant weight gain is misleading, as it can vary widely among individuals. Lastly, Tamoxifen is not a first-line treatment for all cancers; its use is specific to hormone