Longitudinal study of Chinese patients with pernicious anaemia

Background: The survival of whites who have been treated for pernicious anaemia (PA) is unaffected, apart from incurring a greater risk of gastric cancers. The long term outcome of PA in Chinese is unknown. Methods: A hospital based prospective longitudinal study of Chinese PA patients was conducted. Patients with known cancers were excluded. Results: From 1994 to 2007, 199 intrinsic factor antibody (IFA) positive and 168 IFA negative patients were recruited. Both cohorts had similar baseline characteristics, except the IFA positive patients had more severe haematological findings and more thyrogastric immune features; also more IFA negative patients had type 2 diabetes mellitus and gastrointestinal (GI) disease or GI surgery. Both cohorts had a good haematological response but an unsatisfactory neurological response to treatment. Hypothyroidism developed in patients of both cohorts during follow-up. 24 IFA positive patients and 7 IFA negative patients developed cancers (p=0.007) during follow-up. 20% of all cancers were gastric carcinoma. Mean survival of both cohorts was similar. Mean survival of IFA positive patients with and without cancers was 64 and 129 months, respectively (p<0.001), and that of IFA negative patients 36 and 126 months, respectively (p<0.001). Death rates were 31% in the IFA positive cohort and 21% in the IFA negative cohort (p=0.028). Cancer related death rates of IFA positive and IFA negative cohorts were 37% and 14%, respectively (p=0.014). Conclusion: The survival period of Chinese with PA who have received treatment is good, but there is an increased risk of gastric cancers. IFA positive patients have a higher risk of developing all types of cancers and cancer related deaths than IFA negative patients.