Which symptom is NOT a red flag for cancer?

In the context of identifying potential indicators of cancer, the correct answer highlights that an increased appetite is not commonly associated with cancer as a red flag symptom. Instead, cancer-related symptoms typically encompass changes that suggest negative alterations to the body's normal functioning, such as unexplained weight loss, which can indicate a metabolic shift due to cancer, as well as feelings of malaise, which may be the body’s response to systemic illness.

Night sweats are also a significant symptom that can indicate the presence of cancer, particularly in lymphoproliferative disorders. In contrast, an increased appetite generally suggests a healthy metabolic state and does not align with the symptoms that typically raise concerns regarding an underlying malignancy. Thus, out of the provided options, an increased appetite is distinct in not being a warning sign for cancer.