Factors of Delayed Postoperative Radiotherapy in Head and Neck Cancer

Introduction: The Commission on Cancer (CoC) approved initiation of postoperative radiotherapy (PORT) within 6 weeks after surgical resection for Head and Neck Squamous Cell Carcinoma (HNSCC) as its first and only quality metric for head and neck cancer. Identification of factors associated with PORT delays is necessary to adjust for case mix across institutions and target resources to patients at highest risk of delay.

Methods: Following PRISMA guidelines, we performed a systematic review of PubMed, Scopus, and CINAHL. We included studies that described factors associated with PORT delay in patients with HNSCC treated in the US from 2004 or later. A meta-analysis of odds ratios (OR) was performed on non-overlapping datasets. Only studies with PORT delay defined as > 6 weeks (the definition utilized by the CoC and NCCN guidelines) were included in meta-analysis. Heterogeneity was assessed using Q test and I2 statistic.

Results: Of 672 unique abstracts screened, 33 studies were included in the systematic review. Seventeen (51.5%) were single-institution studies (14 academic centers, 2 urban community hospitals, 1 VA center), 2 (6.1%) were multi-institutional, and 14 (42.4%) utilized cancer registry data. Study sample sizes ranged from 14 to 60,776 patients. Twenty-five studies (75.8%) defined PORT delay as > 6 weeks, 3 (9.1%) defined PORT delay as an interval other than > 6 weeks, and 5 (15.2%) described time-to-PORT without defining delay. Factors associated with PORT delay include female sex (OR 1.3, 95% CI 1.2 to 1.3), Black race (OR 1.5, 95% CI 1.4 to 1.6), public insurance or self-pay (OR 1.9, 95% CI 1.8 to 2.0), postoperative length of stay > 7 days (OR 2.5, 95% CI 1.1 to 5.6), 30-day hospital readmission (OR 1.3, 95% CI 1.2 to 1.4), and postoperative complication (OR 2.0, 95% CI 1.1 to 3.6).

Conclusions: Multiple patient- and facility-level factors are associated with PORT delays. These data can be used to adjust PORT delay rates for variable case mix and highlight at-risk groups to whom interventions to improve timely PORT can be targeted.