Final answer:
In the context of group therapy for breast cancer patients, the statement indicative of altruism is offering volunteer help for transportation to appointments, as it demonstrates selfless concern for others without expecting personal gains.
Step-by-step explanation:
A nurse conducting group therapy with clients who have breast cancer should recognize that an example of altruism is the statement, "I am volunteering to help other cancer patients with transportation to appointments." This action represents a selfless concern for the well-being of others, as altruism is characterized by the practice of disinterested and selfless helping of others without expecting anything in return. It is a form of prosocial behavior where the motivation lies in the desire to help others, even if there are personal costs involved.