Is Neck Radiotherapy Necessary in Early-Stage Oral Cancer?

Can Unnecessary Treatment Be Avoided?

Oral cavity cancer is a major public health problem, with approximately 390 thousand new cases worldwide each year. These cancers involve the lips, front of the tongue, palate, floor of the mouth, inner cheeks, and gums. Surgery is the standard treatment for oral cavity cancer, and in some situations postoperative radiotherapy (radiotherapy after surgery) is recommended to complement surgery. However, particularly in early-stage patients without metastases in the neck lymph nodes (pN0), the need for and benefit of additional neck radiotherapy remain debated.

To provide a clearer answer, a multicenter retrospective study in the Netherlandsexamined treatment focused solely on the tumor bed without neck irradiation and found that it could be effective while causing fewer adverse effects . The results were published on April 19, 2025, in Radiotherapy and Oncology .

Study Methods: Who Received Which Treatment?

Researchers analyzed data collected between 2010–2019 at 12 radiotherapy centers in the Netherlands from 264 patients. All patients had undergone surgery for oral cavity cancer, with en bloc tumor and neck dissection. Pathological examination of the neck lymph nodes found no metastases (pN0).

Patients were divided into two groups:

• Radiotherapy to the tumor bed alone (n = 118)

• Radiotherapy to the tumor bed + neck (n = 146)

Radiotherapy doses varied according to surgical margin status and other risk factors. The primary endpoint was the regional recurrence rate, and secondary endpoints were local recurrence, overall survival and late post-treatment adverse effects (assessed after 3 months).

Key Findings: No Difference in Regional Control, but a Major Difference in Adverse Effects

Regional control rate:

• At 5 years, both groups achieved 96% (no statistically significant difference)

• Only 9 regional recurrences occurred overall (3.4%)

  • Tumor-bed-only group: 4 cases (3.39%)

  • Tumor + neck group: 5 cases (3.42%)

Local control rate:

• Tumor-bed-only group: 92%

• Tumor + neck group: 91%

5-year overall survival:

• Tumor-bed-only group: 80%

• Tumor + neck group: 78%

The number of lymph nodes removed (lymph node yield)was significantly associated with better regional control (HR: 0.46).

Adverse Effects: Neck Radiotherapy Increases Late Toxicity

Late adverse effects were markedly more frequent in patients who received neck radiotherapy:

• Dry mouth (Grade 2-3):

  • 31% in the neck-irradiated group

  • 15% in the tumor-bed-only group

  • Odds ratio (OR): 4.93

• Difficulty swallowing (Grade 2-3):

  • 61% in the neck-irradiated group

  • 19% in the other group

  • Odds ratio (OR): 5.29

These differences were both statistically and clinically significant.

Clinical Interpretation: Neck Radiotherapy Is Not Always Necessary

In patients with a pathologically negative neck (pN0) who underwent en bloc neck dissection, tumor-bed-only radiotherapy achieved a regional control rate equal to that in patients who also received neck irradiation, but with substantially fewer adverse effects.

These findings suggest that, in patients whose high-risk pathological findings are confined to the primary tumor and whose neck is clear, neck radiotherapy may be omitted. This strategy is particularly important for avoiding late adverse effects that impair quality of life.

Conclusion: An Individualized Approach to Radiotherapy Is Possible

In patients whose surgery was successfully completed and whose neck nodes were negative, this study indicates that limiting the radiotherapy field may be safe and effective . It also supports an approach that could improve quality of life and minimize late adverse effects such as dry mouth and difficulty swallowing.

The study could pave the way for tumor-bed-focused adjuvant treatment to become standard in selected patient groups.