Causes of Salivary Gland Cancer
Environmental and Occupational Exposures
Radiation exposure to the head and neck region is the most consistently established risk factor for salivary gland cancer. 1
Radiation-Related Risk Factors
- Therapeutic medical radiation to the head or neck increases risk 2.6-fold, particularly for exposures before 1955 when doses were substantially higher 1
- Full mouth dental x-rays are associated with a 1.6-fold increased risk, with the elevation primarily limited to pre-1955 exposures when radiation doses were considerably greater 1
- Ultraviolet light treatment to the head or neck carries a 1.9-fold increased risk 1
- Occupational exposure to radiation or radioactive materials increases risk 2.4-fold 1
Industrial and Chemical Exposures
- Occupational exposure to nickel compounds or alloys carries a 6-fold increased risk 1
- Employment in the rubber industry is associated with a 7-fold increased risk, though this finding is based on limited cases 1
Lifestyle Factors
Tobacco and Alcohol (Gender-Specific Effects)
- In men specifically, current smoking increases risk 2.1-fold and heavy alcohol consumption (>7 drinks/week) increases risk 2.5-fold 1
- These associations are notably absent in women, suggesting gender-specific mechanisms 1
- Chewing tobacco and snuff use show no association with salivary gland cancer risk 2
Dietary Factors
- Consumption of four or more servings per week of processed meat products increases risk 1.6-fold 3
- High consumption of spinach/squash and overall vegetable intake show protective trends, though not statistically significant 3
Genetic Predisposition
Hereditary breast cancer susceptibility genes, particularly BRCA1 and BRCA2 mutations, are associated with increased salivary gland cancer risk. 4
- Families with BRCA1 or BRCA2 pathogenic variants demonstrate occurrence of salivary gland cancers, including in male carriers 4
- Loss of heterozygosity of BRCA wild-type alleles has been documented in tumor DNA from affected patients 4
- Patients with salivary gland cancer show increased risk of secondary malignancies, particularly breast cancer 4
Body Habitus
- Low body mass index in men is associated with reduced risk (OR 0.46), though no relationship exists in women 2
- Obesity shows a nonsignificant trend toward increased risk 3
Important Caveats
The evidence base for salivary gland cancer etiology is limited by the rarity of this malignancy, with most studies involving small case numbers. 1, 2, 3 Many identified associations, particularly for dietary and lifestyle factors, do not reach statistical significance and require confirmation in larger studies. 3 The heterogeneous histological subtypes of salivary gland cancer may have distinct etiologies that are obscured in combined analyses. 5