Which of the following is a common symptom of cancer?

Weight changes are a common symptom of cancer due to several factors related to the disease and its treatment. Many individuals with cancer may experience unexplained weight loss as the body requires more energy to deal with the disease process, and cancer can also affect metabolism and appetite. Additionally, some types of cancer can cause physical changes in the body that lead to decreased appetite or difficulty absorbing nutrients, further contributing to weight loss. Conversely, some people may see weight gain, particularly if they are on medications such as corticosteroids that can increase appetite or cause fluid retention.

In contrast, improved stamina, increased appetite, and heightened energy are not typical symptoms associated with cancer. Instead, many cancer patients often face fatigue, decreased appetite, and energy levels due to the illness and its treatments, highlighting why they are not the correct answers in this context.