Long-term survival of gastrointestinal cancer diagnosed in Hodgkin lymphoma survivors.

Abstract

40 Background: The risk of developing gastrointestinal (GI) cancer is increased in Hodgkin lymphoma survivors. This study aims to compare overall survival of GI cancer in Hodgkin lymphoma survivors with survival of first primary GI cancer patients. Methods: This cohort study compared overall survival of GI cancer patients in a Hodgkin lymphoma survivor population (HL-GI (n = 92) including esophageal (n = 25), gastric (n = 31), small intestinal (n = 2), colorectal cancer (n = 34)) with survival of a population-based cohort of first primary GI cancer patients (GI-1, n = 911) which was generated by individual matching of the 92 cases, based on tumor location, gender, age and year at diagnosis. Clinical characteristics were compared by Chi square tests. Cox regression was used for multivariable survival analysis (corrected for age, gender, and clinicopathological characteristics related to the GI tumor). Results: When comparing HL-GI and GI-1 patients, no differences in tumor stage, grade of differentiation or frequency of surgery were found. HL-GI patients were less frequently treated for their GI tumor with radiation therapy (7% vs. 24% in GI-1 patients, p < 0.001) or chemotherapy (28% vs. 41%, p = 0.02). Overall 5-year and 20-year survival of HL-GI patients and GI-1 patients was non-significantly lower (28% vs. 38%, p = 0.13 and 19% vs. 29%, p = 0.06, respectively). This result was confirmed multivariably (5-year survival, p = 0.33, 20-year survival, p = 0.14). Also, for esophageal, gastric and colorectal cancer separately, no differences in overall survival were found between HL-GI patients and GI-1 patients. Conclusions: Long-term overall survival of GI cancer patients is similar in Hodgkin lymphoma survivors and first primary GI cancer patients. HL-GI patients did however receive less treatment with radiation therapy or chemotherapy. These treatments may not have been recommended due to prior Hodgkin lymphoma treatment or comorbidity. As risks of other causes of mortality are also increased in Hodgkin lymphoma survivors, the relatively good survival in this population is remarkable.