Adapted cancer treatment can result in fewer side effects

23 June 2016

Cancer treatments often result in negative side effects and doctors have to choose a therapy that has the best chance to succeed while keeping toxicity as low as possible. In a new international study, Uppsala researchers have studied a way of identifying those patients with Hodgkin lymphoma that can be cured with a milder therapy, so that a more intensive treatment can be reserved for patients with poorer prognoses.

The most common treatment for patients with the tumour form Hodgkin lymphoma is different regimes of chemotherapy. In later years these therapies have become more efficient and survival rates have steadily improved. However, chemotherapy has many severe side effects, of which some can be long-term, which can be problematic when a majority of patients have a long life expectancy after completed treatment.

Gunilla Enblad at the Department of Immunology, Genetics and Pathology has participated in an international study where it was observed that an interim PET/CT scan can be used to adapt chemotherapy by intensifying the therapy for patients with the highest risk of treatment failure while patients with a good outlook can receive a milder treatment, with fewer side effects.

The study included more than 1200 patients diagnosed with Hodgkin lymphoma. All participants initially received a standard treatment, which included a baseline PET/CT scan and two cycles of a milder chemotherapy called ABVD. After the second cycle an interim PET/CT scan was performed to select patients for different regimes of continued therapy.

‘In a PET/CT scan the uptake of the substance FDG is analysed and previous retrospective studies had suggested that patients with a low FDG uptake had a better survival than those with a high uptake. Patients in our study showing high values, approximately 15 per cent of the participants, therefore received a more intense chemotherapy compared to the standard regime. At the follow-up after three years, two thirds of these patients showed progression-free survival. This was substantially better than reported from retrospective studies where patients continued on ABVD therapy, and in keeping with other series in which patients received a similar treatment to the one in our study’, says Gunilla Enblad.

Unfortunately, ABVD treatment also has some severe side effects. One of the included substances, bleomycin, can damage the lungs and the researchers therefore wanted to investigate if the treatment had the same effect on the disease if bleomycin was omitted. Patients that showed low FDG uptake in the interim PET/CT scan, and were to continue with the milder chemotherapy, were therefore randomised into two groups. One of the groups continued on ABVD treatment whereas the other received a corresponding therapy, but without bleomycin.

‘Our results showed no significant difference in treatment outcome in the two groups. Patients who received therapy without bleomycin had the same survival rate as those who got the regular treatment. However, they did display fewer side effects and we conclude that omitting bleomycin following a negative interim PET-CT scan should be used as the standard approach’, says Gunilla Enblad.

The study has been published in New England Journal of Medicine and is a collaboration between scientists in Sweden, United Kingdom, Norway, Denmark, Italy, New Zeeland and Australia.