RISK-FACTORS FOR THE DEVELOPMENT OF ESOPHAGEAL CANCER AS A 2ND PRIMARY TUMOR

Exposure to irradiation or chemotherapy as well as prolonged exposure to risk factors, such as alcohol and tobacco, may induce a second prim ary carcinoma of the oesophagus. To estimate the potential risk of pre vious treatment regimens, we performed a case-control study. In the Tu mour Registry of The Netherlands Cancer Institute, from 1955, 27 cases of squamous cell carcinoma of the oesophagus were identified followin g treatment for malignant lymphoma (n = 11), breast cancer (n = 8) and lung cancer (n = 8). The median interval was 6.6 years (range 1-16). Preferably 3 controls from the same tumour registry were matched to ea ch case on,he basis of sex, age, primary tumour, location of primary t reatment (academic or general hospital), calendar year at diagnosis of primary tumour and duration of follow-up. Clinical data and details o f treatment were obtained from the medical records. In patients who ha d smoked for more than 5 years, there was a 3.2-fold increased risk of oesophageal carcinoma (P = 0.04); for those with a regular alcohol in take the relative risk was 3.3 (P = 0.01). There was no significant re lationship between irradiation of the mediastinum and subsequent risk for oesophageal cancer. The number of chemotherapy-treated patients wa s too small to calculate the relative risk associated with cytostatic drugs. In conclusion, oesophageal cancer as second primary cancer is e xtremely rare. Risk factors include the well known abuse of alcohol an d tobacco. No significant relationship with previous mediastinal irrad iation could be demonstrated.