Comparing Travel Distance to Care and Staging of Parotid Gland Malignancies in South Dakota and Surrounding States

Background: Parotid gland malignancies are difficult to characterize in terms of incidence and risk factors due to their relatively rare occurrence. Common cancers often present more aggressively in rural areas, albeit occurring less frequently. Some previous studies have found increased distance to care has been linked to more advanced malignancies. This study hypothesized decreased access to parotid gland malignancy specialists (otolaryngologists or dermatologists), evaluated as longer travel distances, would be associated with more advanced staging of parotid gland malignancies.

Methods: A retrospective chart review of the Sanford Health system electronic medical record in South Dakota and surrounding states from 2008-2018 was conducted to obtain data of parotid gland malignancies, respective staging, and patient home addresses to assess distance, both driving and straight-line, to the nearest parotid gland malignancy specialist, including outreach clinics. Travel distance was categorized (0-20 miles, 20-40 miles, and 40+ miles) and compared to categorized tumor stage (early 0/I, late II/III/IV) using a Fisher's Exact test.

Results: Overall, chart review yielded 134 patients with parotid gland malignancies from 2008-2018 in the Sanford Health system and associated data was gathered. The malignancies were categorically organized as 52.3 percent in early stage (0/I) vs. 47.7 percent in late (II/III/IV). When comparing parotid malignancy stage to driving distance, no significant association was found when outreach clinics were excluded (p=0.938) or included (p=0.327). When comparing parotid malignancy stage to straight-line distance, no significant association was found when outreach clinics were excluded (p=0.801) or included (p=0.874).

Conclusions: Although no association was established between travel distance and parotid gland malignancy staging, further studies are needed to evaluate at population levels the incidence of parotid gland malignancies in rural communities and if there are specific risk factors in these areas for these malignancies which is currently unknown.