Pregnancy does not increase risk of Hodgkin lymphoma recurrence

Pregnancy does not increase the risk of relapse among women successfully treated for Hodgkin lymphoma. This according to a new study from Sweden's Karolinska Institutet and Uppsala University published in The Journal of Clinical Oncology.

Hodgkin lymphoma is a cancer that originates in the lymphocytes (white blood cells). It affects 160 people in Sweden every year. Unlike other types of lymphoma, a high proportion of patients develop Hodgkin lymphoma in their 20s and 30s. Many women wish to become pregnant following treatment. Prognosis is very good; a previous study from the same research group at Karolinska Institutet estimated that 5-year relative survival for women diagnosed up to age 50 in Sweden was close to 95 percent.

The present study included 449 women between the ages of 18 and 40 diagnosed with Hodgkin lymphoma between 1992 and 2009. The study investigated whether women who had responded successfully to treatment and subsequently became pregnant ran a higher risk of relapse than women who did not become pregnant. The study was conducted to alleviate concerns expressed by patients and some doctors and midwives, since the topic had not previously been rigorously examined.

"We know that a suppressed immune system or certain inflammatory conditions increase the risk of developing Hodgkin lymphoma," says researcher Caroline Weibull, biostatistician and doctoral student at Karolinska Institutet's Department of Medical Epidemiology and Biostatistics, "and since pregnancy affects the immune system, we wanted to see if there was a statistical correlation between pregnancy and risk of relapse."

Among the 449 women in the study, 144 women gave birth during the follow-up period. In total, 47 women had a relapse but only one woman experienced a relapse within five years of giving birth. The results of this study therefore provide no evidence that pregnancy increases the risk of relapse in women who have been successfully treated for Hodgkin lymphoma.

"The risk of relapse is at its highest during the first two or three years of diagnosis," says Dr Ingrid Glimelius, oncologist at Akademiska Hospital in Uppsala and a researcher affiliated to both Karolinska Institutet's Department of Medicine (Solna) and the Department of Immunology, Genetics and Pathology at Uppsala University. "At the same time, treatment of the primary disease and a possible relapse can cause premature menopause and, at worst, infertility. Survivors of Hodgkin lymphoma need to consider a range of factors when deciding about future reproduction. However, given the results of this study, the risk of pregnancy-associated relapse does not need to be considered.