In Sweden, 3604 salivary gland tumor cases in adults 20 years or older were identified during the period 1970-2009, of whom 2624 (73%) were malignant neoplasms of the parotid gland. The incidence of parotid gland tumors in Sweden decreased slightly during the early study period, and then remained stable for both sexes (0.9/100,000 person-years in 1970 and 0.8/100,000 person-years in 2009 for men; 0.7/100,000 person-years in both 1970 and 2009 for women).
The age-standardized incidence rate of salivary gland tumors in the whole Nordic population during the period 1970-2009 was 1.1/100,000 for men (4440 cases) and 0.9/100,000 for women (4178 cases). No increase in incidence was observed; the annual percent change was -0.1% for men and -0.2% for women.
The authors concluded that if mobile phone use were a noticeable risk factor for parotid gland tumors, some increase of the incidence rate would have been seen in the Nordic countries unless the latency period exceeds 15-20 years. The results suggest other explanations for increases in the registered incidence of parotid gland tumors observed in Israel and United Kingdom.