In patients who underwent surgical treatment for stage I or II oral cavity squamous cell cancer, positive tumor margin, the use of radiation or chemotherapy, treatment in a nonacademic facility, and having public health insurance were significantly associated with lower 5-year survival rates, according to a retrospective analysis published online in the JAMA Otolaryngology–Head & Neck Surgery.
The findings suggest that some factors associated with lower 5-year survival rates “may be targets for quality improvement efforts,” wrote Alexander L. Luryi of Yale University, New Haven, Conn., and colleagues.
Seventy percent of 6,830 patients who underwent surgery for stage I or II oral cavity squamous cell cancer (OCSCC) from 2003 to 2006 survived 5 years, according to information from the National Cancer Data Base.
Multivariate analysis showed higher survival rates were significantly associated with neck dissection (hazard ratio, 0.85; P = .003). Lower survival rates were significantly associated with radiation therapy (HR, 1.31; P < .001), chemotherapy (HR, 1.34; P = .03), nonprivate insurance (HR Medicaid, 1.96; HR Medicare, 1.45; P < .001), and nonacademic treatment facility (HR, 1.13; P = .03).
Care at academic centers compared with nonacademic centers was associated with improved survival, possibly due to health care provider expertise, the study authors noted (JAMA Otolaryngol. Head Neck Surg. 2015 May 14 [doi:10.1001/jamaoto.2015.0719]).
Survival rates were lower in patients treated at nonacademic cancer centers, but multivariate analysis showed no association between facility-based case volume and survival. Patients insured through Medicaid and Medicare had significantly lower 5-year survival rates (P < .001 for both). That finding may be the result of inconsistent treatment and follow-up, the investigators said, or worse baseline health among that patient population.
Controversy exists over the relationship between positive margins and outcomes, and the implications for aggressiveness of surgery. The study found positive margins were significantly associated with poorer outcomes, the researchers noted, which supports the use of aggressive surgery in early OCSCC to achieve negative margins.
Radiation and chemotherapy were linked to worse outcomes, and those therapies were possibly indicators of less aggressive resection in localized disease. The analysis could not adjust for potential confounding effects of perineural and lymphovascular invasion, because the information was not recorded in the National Cancer Data Base.
The study indicated a positive impact by neck dissection on survival. Patients with occult neck disease who underwent neck dissection likely would have been restaged to stage III or higher and removed from the early stage sample, the authors explained, which would account for higher survival rates for those remaining. Prospective trials are needed to determine the role of elective neck dissection in early OCSCC, the researchers added.
The William U. Gardner Memorial Research Fund at Yale University supported the study. Dr. Luryi and coauthors reported having no disclosures.