This clinical trial focuses on patients with neuroendocrine neoplasms (NENs), which are rare tumors that can develop in various parts of the body, particularly in the digestive system and lungs. The study specifically looks at patients who cannot receive standard cancer treatments due to their health condition. The treatment being tested is Temozolomide, a cancer medication that will be given in low doses continuously over time, which is known as metronomic therapy.

The study will examine how well this treatment works in preventing cancer progression in patients who have advanced or spreading NENs. The medication will be given as oral capsules that patients can take at home. The treatment period may last up to 12 months, with patients taking a daily dose of the medication.

The researchers will monitor how the disease responds to the treatment and track any side effects that may occur. They will also study certain characteristics of the tumors to understand which patients might benefit most from this treatment approach. This includes examining a specific marker called O6-methylguanine-DNA-methyltransferase (MGMT) in the tumor tissue, which may help predict how well the treatment will work.