Oncologic Safety of Close Margins in Patients With Low- to Intermediate-Grade Major Salivary Gland Carcinoma
Bibliographic record
Abstract
Importance: Postoperative radiation therapy for close surgical margins in low- to intermediate-grade salivary carcinomas lacks multi-institutional supportive evidence. Objective: To evaluate the oncologic outcomes for low- and intermediate-grade salivary carcinomas with close and positive margins. Design, Setting, and Participants: The American Head and Neck Society Salivary Gland Section conducted a retrospective cohort study from 2010 to 2019 at 41 centers. Margins were classified as R0 (negative), R1 (microscopically positive), or R2 (macroscopically positive). R0 margins were subclassified into clear (>1 mm) or close (≤1 mm). Data analysis was performed from June to October 2023. Main Outcomes and Measures: Main outcomes were risk factors for local recurrence. Results: A total of 865 patients (median [IQR] age at surgery, 56 [43-66] years; 553 female individuals [64%] and 312 male individuals [36%]) were included. Of these, 801 (93%) had parotid carcinoma and 64 (7%) had submandibular gland carcinoma, and 748 (86%) had low-grade tumors and 117 (14%) had intermediate-grade tumors, with the following surgical margins: R0 in 673 (78%), R1 in 168 (19%), and R2 in 24 (3%). Close margins were found in 395 of 499 patients with R0 margins (79%), for whom margin distances were measured. A total of 305 patients (35%) underwent postoperative radiation therapy. Of all 865 patients, 35 (4%) had local recurrence with a median (IQR) follow-up of 35.3 (13.9-59.1) months. In patients with close margins as the sole risk factor for recurrence, the local recurrence rates were similar between those who underwent postoperative radiation therapy (0 of 46) or observation (4 of 165 [2%]). Patients with clear margins (n = 104) had no recurrences. The local recurrence rate in patients with R1 or R2 margins was better in those irradiated (2 of 128 [2%]) compared to observed (13 of 64 [20%]) (hazard ratio [HR], 0.05; 95% CI, 0.01-0.24). Multivariable analysis for local recurrence found the following independent factors: age at diagnosis (HR for a 10-year increase in age, 1.33; 95% CI, 1.06-1.67), R1 vs R0 (HR, 5.21; 95% CI, 2.58-10.54), lymphovascular invasion (HR, 4.47; 95% CI, 1.43-13.99), and postoperative radiation therapy (HR, 0.10; 95% CI, 0.04-0.29). The 3-year local recurrence-free survivals for the study population were 96% vs 97% in the close margin group. Conclusions and Relevance: In this cohort study of patients with low- and intermediate-grade major salivary gland carcinoma, postoperative radiation therapy for positive margins was associated with decreased risk of local recurrence. In isolation from other risk factors for local recurrence, select patients with close surgical margins (≤1 mm) may safely be considered for observation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.004 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".