When is progressive disease diagnosed?

Progressive disease is diagnosed when there is a notable increase in tumor burden, specifically when the tumor growth exceeds 25% compared to its size at the last assessment. This assessment is often part of monitoring the effectiveness of treatment in oncology, allowing healthcare providers to determine whether the current therapeutic approach is effective or if a change in treatment strategy is necessary. Assessing tumor progression is crucial as it informs decisions on subsequent treatment modalities or clinical trials.

The other options pertain to different disease states. For example, a reduction in tumors in size without new growth indicates a response to treatment, rather than progression. The definition of stable disease is when there is no significant change in tumor size for a given period, while progressive disease specifically refers to an increase, not stability or reduction in size. Thus, knowing the precise criteria for progressive disease assists in managing treatment effectively.