What is the role of combined chemotherapy and radiation in early-stage Hodgkin lymphoma?

This study explored whether radiation therapy was necessary in patients with early-stage Hodgkin lymphoma. The study concluded that disease progression occurred more often in patients who did not undergo radiation.

The standard treatment option for early stage Hodgkin lymphoma is chemotherapy followed by radiation. Radiation can lead to many late negative effects (such as second cancers). It would be useful to know if it could be avoided in any patients. There are so far no factors that can predict which patients can avoid radiation.

PET scans use a radioactive substance to image organs and tissues. It can also highlight cancer activity. A PET scan after the first two cycles of chemotherapy may be useful in predicting prognosis. Patients who do not have cancer activity on a PET scan after two cycles have been found to have better progression-free survival (time from treatment until disease progression) than patients who do show cancer activity. Whether or not PET scan results can help to determine what patients need radiation is not yet clear.

The current study examined whether PET scan results could identify patients who did not need radiation. The study included 1,137 patients. 693 patients had unfavorable disease, based on other risk factors. 444 had favorable disease. All patients were treated with two cycles of the chemotherapy ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) followed by PET scan. Patients without cancer activity on the PET scan (PET negative) were treated with two or four more cycles of ABVD. Patients with cancer activity were treated with a different chemotherapy regimen and radiation. A second group of patients were treated with standard treatment (1 or 2 more ABVD cycles followed by radiation). Patients were followed for an average of 1.1 years.

Of the patients with favorable disease who were PET negative, 4.6% of patients not treated with radiation saw disease progression. This was compared to 0.5% of patients treated with radiation. In patients with unfavorable disease and no PET activity, 5.9% of patients not treated with radiation saw disease progression, and 1 patient died. In those treated with radiation, 2.8% experienced disease progression.

This study concluded that a combined treatment of chemotherapy and radiation led to fewer disease progressions in patients with no disease activity on PET scan.