What tumor marker is used to determine treatment and prognosis for non-small cell lung cancer and anaplastic large cell lymphoma?

The ALK gene rearrangements are a significant tumor marker for both non-small cell lung cancer (NSCLC) and anaplastic large cell lymphoma (ALCL). In the context of NSCLC, the presence of ALK rearrangements indicates a specific subtype of lung cancer that may respond well to targeted therapies such as crizotinib, a treatment that specifically inhibits the abnormal ALK protein. The identification of this marker can therefore play an essential role in determining the most effective course of treatment and also provides insights into the prognosis of the patient.

Moreover, in anaplastic large cell lymphoma, ALK positivity can help classify the type of lymphoma, further guiding treatment decisions. Patients with ALK-positive ALCL typically have a better prognosis compared to those who are ALK-negative.

This specific utility of ALK rearrangements in both malignancies emphasizes their importance in personalized medicine, as they not only influence treatment options but also help in forecasting the likely disease progression based on the presence or absence of the ALK gene alteration.

The other options, while relevant in different contexts, do not specifically serve the dual purpose of guiding treatment and prognostication for both NSCLC and ALCL.