Comparing the clinical outcomes of initial surgery and primary definitive radiotherapy with a dosage of 6600 cGy or higher in cT1-2N0M0 oral cavity squamous cell carcinoma: A nationwide cohort study

Cancer Med. 2024 May;13(10):e7127. doi: 10.1002/cam4.7127.

Abstract

Background: To compare the clinical outcomes of two treatment modalities, initial surgery and primary definitive radiotherapy (RT), in Taiwanese patients diagnosed with cT1-2N0M0 oral cavity squamous cell carcinoma (OCSCC).

Methods: Between 2011 and 2019, we analyzed data for 13,542 cT1-2N0M0 patients who underwent initial surgery (n = 13,542) or definitive RT with a dosage of at least 6600 cGy (n = 145) for the treatment of OCSCC. To account for baseline differences, we employed propensity score (PS) matching, resulting in two well-balanced study groups (initial surgery, n = 580; definitive RT, n = 145).

Results: Before PS matching, the 5-year disease-specific survival (DSS) rates were 88% for the surgery group and 58% for the RT group. After PS matching, the 5-year DSS rates of the two groups were 86% and 58%, respectively. Similarly, the 5-year overall survival (OS) rates before PS matching were 80% for the surgery group and 36% for the RT group, whereas after PS matching, they were 73% and 36%, respectively. All these differences were statistically significant (p < 0.0001). A multivariable analysis identified treatment with RT, older age, stage II tumors, and a higher burden of comorbidities as independent risk factors for both DSS and OS. We also examined the 5-year outcomes for various subgroups (margin ≥5 mm, margin <5 mm, positive margins, RT combined with chemotherapy, and RT alone) as follows: DSS, 89%/88%/79%/63%/51%, respectively, p < 0.0001; OS, 82%/79%/68%/39%/32%, respectively, p < 0.0001.

Conclusions: In Taiwanese patients with cT1-2N0M0 OCSCC, a remarkably low proportion (1.1%) completed definitive RT. A significant survival disparity of 30% was observed between patients who underwent initial surgery and those who received definitive RT. Interestingly, even patients from the surgical group with positive surgical margins exhibited a significantly superior survival compared to those in the definitive RT group.

Keywords: cT1−2N0M0; cancer registry; clinical outcomes; definite radiotherapy; oral cavity squamous cell carcinoma; surgery.

Publication types

  • Comparative Study

MeSH terms

  • Adult
  • Aged
  • Carcinoma, Squamous Cell / mortality
  • Carcinoma, Squamous Cell / pathology
  • Carcinoma, Squamous Cell / radiotherapy
  • Carcinoma, Squamous Cell / surgery
  • Female
  • Humans
  • Male
  • Middle Aged
  • Mouth Neoplasms* / mortality
  • Mouth Neoplasms* / pathology
  • Mouth Neoplasms* / radiotherapy
  • Mouth Neoplasms* / surgery
  • Neoplasm Staging
  • Propensity Score
  • Radiotherapy Dosage
  • Retrospective Studies
  • Squamous Cell Carcinoma of Head and Neck / mortality
  • Squamous Cell Carcinoma of Head and Neck / pathology
  • Squamous Cell Carcinoma of Head and Neck / radiotherapy
  • Squamous Cell Carcinoma of Head and Neck / surgery
  • Survival Rate
  • Taiwan / epidemiology
  • Treatment Outcome