Comment to: Secondary malignancies after treatment for indolent non-Hodgkin’s lymphoma: a 16-year follow-up study. Haematologica 2008; 93:398-403

Dear editor,

Sacchi et al. report the standardized incidence ratio for secondary malignancies after treatment for indolent non-Hodgkin’s Lymphoma in a large database from the Gruppo Italiano Studio Linfomi. We believe that the 16-year follow-up, suggested in the title, is overestimated considering a median follow-up of 5.1 years. More importantly, a marked 20-fold higher Absolute Excess Risk (AER) in men compared with women was reported, which is unlikely due to treatment differences. Moreover, the reported AER of +1.01 in men appears incorrect. Given the numbers in table 2 and 4, we calculated an AER of +1.22. A previous study in aggressive non-Hodgkin’s lymphoma did not show a significant difference between the sexes.1 Can the authors speculate on the origin of the difference between men and women?

The authors then conclude that their study helps to select the most appropriate treatment. We question this, since at present indolent non-Hodgkin’s lymphoma is unfortunately not curable. Therefore, patients will always receive the most optimal first-line therapy (including fludarabine) for their disease, regardless of long-term treatment-related side-effects, especially since the numbers of secondary cancer are relatively low. Moreover, non-Hodgkin’s lymphoma is diagnosed at a median age of 60–65 years, leaving the increased risk of secondary malignancy only applicable to half of the patients. We, therefore, state that clinical practice at this moment will not likely be influenced by their study results.