Gemcitabine hydrochloride is widely used in the treatment of various cancers, particularly pancreatic cancer, where it is often the first-line chemotherapy agent. It is also effective in treating non-small cell lung cancer, breast cancer, and ovarian cancer. The drug works by inhibiting DNA synthesis, which prevents cancer cells from multiplying and leads to their destruction. In combination therapy, it enhances the efficacy of other anticancer drugs, making it a valuable component in multimodal treatment regimens. Additionally, it is used in palliative care to alleviate symptoms and improve the quality of life for patients with advanced-stage cancers. Its relatively manageable side effect profile compared to other chemotherapeutic agents makes it a preferred choice in many clinical scenarios.