Antiretroviral treatment during chemotherapy greatly improved the chance of successful treatment of aggressive types of lymphoma

People with HIV treated for aggressive forms of non-Hodgkin lymphoma or Burkitt lymphoma appear no more likely to suffer a relapse after treatment than HIV-negative people treated for the same conditions, according to findings of an analysis of the German HIV Lymphoma Cohort published this month in Haematologica, the journal of the European Hematology Association.

Non-Hodgkin lymphoma and Burkitt lymphoma are AIDS-defining cancers that occur much more frequently in people with HIV than in the general population. Non-Hodgkin lymphoma is a cancer of lymphocytes (white blood cells) that develops in lymph nodes. The most aggressive form is Diffuse Large B-Cell Lymphoma. Burkitt lymphoma is a form of non-Hodgkin lymphoma that develops in B-lymphocytes and is very aggressive.

Both cancers are treatable with chemotherapy and complete remission is possible in the majority of people treated. Relapse after treatment occurs in about one in ten cases in the general population but German researchers wanted to know if people with HIV suffered higher rates of relapse and whether dose reductions or chemotherapy cycle reductions had any impact on the risk of relapse.

Glossary lymphoma A type of cancer that starts in the tissues of the lymphatic system, including the lymph nodes, spleen, and bone marrow. In people who have HIV, certain lymphomas, such as Burkitt lymphoma, are AIDS-defining conditions. relapse The return of signs and symptoms of a disease after a patient has been free of those signs and symptoms. remission The disappearance of signs and symptoms of a disease, usually in response to treatment. The term is often used in relation to cancer, indicating that there is no evidence of disease, although the possibility of cancer remaining in the body cannot be ruled out. In HIV, remission is an alternative term for ‘functional cure’. A sustained ART-free remission would boost the immune system to induce long-term control of HIV, allowing a person living with HIV to maintain an undetectable viral load without daily medication. chemotherapy The use of drugs to treat an illness, especially cancer. non-Hodgkin lymphoma A group of lymphomas (cancers of the lymphatic system). The many types of non-Hodgkin lymphoma (NHL) are classified according to how fast the cancer spreads. Although the symptoms of NHLs vary, they often include swollen lymph nodes, fever, and weight loss. Certain types of NHLs, such as Burkitt lymphoma and immunoblastic lymphoma, are AIDS-defining cancers in people with HIV.

The study looked at people with HIV in Germany treated for Diffuse Large B-Cell Lymphoma (DLBCL), Burkitt lymphoma, plasmablastic lymphoma (PBL) or non-classifiable B-cell lymphoma since 2005. The treatment cohort consisted of 387 people, of which 254 achieved remission after the first course of treatment, 21 after further chemotherapy, 22 achieved partial remission (reduction in lymphoma mass of at least 50% and no further spread) and 15 were still receiving chemotherapy at the time of analysis. Of the non-responders, 23 died during treatment, 45 had progressive disease and 7 had received no treatment.

A total of 254 achieved complete remission after the first course of treatment (127 with DLBCL, 91 with Burkitt lymphoma, 29 with PBL and seven with other non-classifiable B-cell lymphomas). This group represented just under two-thirds (63%) of those treated. Complete remission from lymphoma was achieved if there was no visible evidence of lymphoma for at least three months after the completion of treatment. Relapse was defined as 50% growth in a previously abnormal lymph node after complete remission.

The primary outcomes evaluated in the study were relapse and 5-year relapse-free survival.

People were followed for a median of 4.6 years after complete remission. During the follow-up period, 11.4% experienced relapse. In comparison, recent studies in HIV-negative people report relapse rates of 6-10% for DLBCL and 12% for Burkitt lymphoma using similar treatment regimens to those employed in this study population.

Five-year relapse-free survival was 88.4% for Diffuse Large B-Cell Lymphoma, 88.9% for Burkitt lymphoma and 88.6% for plasmablastic lymphoma. Survival was much lower for unclassified AIDS lymphoma (57.1%) and the investigators say that these hard-to-classify lymphomas may include especially aggressive atypical lymphomas.

The following factors were associated with relapse:

Higher Ann Arbor score, representing more disseminated disease (stages III/IV) (hazard ratio 4.85, 95% CI 1.44-16.34)

No antiretroviral therapy during chemotherapy (HR 4.28, 95% CI 1.19-15.39)

R-CHOP chemotherapy (HR 7.59, 95% CI 1.87-30.81)

Non-classifiable lymphoma (HR 5.08, 95% CI 1.13-22.08)

The treatment regimens used – R-CHOP or GMALL – last up to four months. GMALL is more intensive and may require in-patient care. Reductions in doses or the number of cycles of chemotherapy may be necessary or advisable depending on the lymphoma stage and general health.

Looking at the treatment course, investigators found that only 37% of patients had a full treatment course, without delay, after diagnosis. There was no difference in outcome in those who received shorter courses of treatment or lower doses for either the R-CHOP or GMALL regimens.

The investigators concluded that “treatment outcomes compare favourably with those patients with NHL [non-Hodgkin lymphoma] and no HIV infection.”