What do systematic reviews say?

PET-CT following chemoradiotherapy (neck dissection only if no/incomplete response) vs Planned neck dissection before or after chemoradiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Disease-free survival: outcome not reported in a usable way (Mehanna 2017: disease-specific and other-cause mortality did not differ, P=0.80 and 0.41).
  1 study
  GRADE not reported

Chemotherapy regimen A (+/- locoregional treatment) vs Chemotherapy regimen B (+/- locoregional treatment)

• Interventions for the treatment of oral cavity and oropharyngeal cancer: chemotherapy 2021 · Cochrane All outcomes
  Induction cisplatin+5-FU+docetaxel vs cisplatin+5-FU: disease-free survival HR 0.72 (95% CI 0.57 to 0.91, P = 0.006; Vermorken 2007). Prior to concurrent chemoradiation: Posner 2007 HR 0.71 (0.56 to 0.90, P = 0.005).…
  2 studies
  GRADE not reported

Concomitant (concurrent) chemoradiotherapy vs Radiotherapy alone

Concomitant (concurrent) chemoradiotherapy led to lower disease-free survival, concurrent chemoradiotherapy vs radiotherapy… compared with radiotherapy alone (non-resectable tumours); GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: chemotherapy 2021 · Cochrane All outcomes
  HR 0.74 [0.67, 0.80]
  13 studies
  GRADE not reported

Surgery plus radiotherapy vs Chemotherapy (chemoradiotherapy)

The review found no eligible studies for this question.

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes

  oral cavity
  Disease-free survival: not reported (Iyer 2015).
  0 studies
  No studies found

Surgery plus radiotherapy vs Radiotherapy alone

The review found no eligible studies for this question.

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Disease-free survival: not reported.
  0 studies
  No studies found

Supraomohyoid neck dissection vs Modified radical neck dissection

The review found no eligible studies for this question.

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes
  Disease-free survival: not reported (Guo 2014 reported disease-specific survival, not a review outcome).
  0 studies
  No studies found

Altered fractionation radiotherapy (hyperfractionated and/or accelerated) vs Conventional (standard) fractionation radiotherapy

Altered fractionation radiotherapy (hyperfractionated and/or… showed no clear difference in disease free survival compared with conventional (standard) fractionation radiotherapy; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  HR 0.85 [0.70, 1.03]
  8 studies
  GRADE not reported
• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Hyperfractionated/accelerated vs conventional, disease free survival: one trial (Poulsen 2001); no statistically significant difference (Analysis 1.3). No pooled estimate.
  1 study
  GRADE not reported

Neutron radiotherapy vs Conventional photon radiotherapy

Neutron radiotherapy showed no clear difference in disease free survival compared with conventional photon radiotherapy; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes

  5 years
  RR 0.63 [0.36, 1.09]
  1 study
  GRADE not reported

Accelerated radiotherapy with concomitant boost vs Conventional (standard) fractionation radiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Accelerated/boost vs conventional, disease free survival: all four trials provided data; pooled estimate showed a statistically significant difference in favour of the accelerated/boost schedule, with statistical…
  4 studies · 1203 participants
  GRADE not reported

Pre-operative and post-operative radiotherapy vs Post-operative radiotherapy alone

Pre-operative and post-operative radiotherapy showed no clear difference in disease free survival compared with post-operative radiotherapy alone; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  HR 1.13 [0.78, 1.64]
  1 study
  GRADE not reported

Split‐course radiotherapy (8 fractions, 30 Gy) vs Accelerated radiotherapy

Split-course radiotherapy showed no clear difference in disease free survival compared with accelerated radiotherapy; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes

  2 years
  RR 0.83 [0.29, 2.42]
  1 study · 110 participants
  GRADE not reported

Hyperfractionated radiotherapy vs Conventional (standard) fractionation radiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Hyperfractionated vs conventional, disease free survival: data available for one trial (Fu 2000); no statistically significant difference (Analysis 1.3). No pooled estimate reported.
  1 study
  GRADE not reported

Hyperfractionated/accelerated/split-course radiotherapy vs Conventional (standard) fractionation radiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Hyperfractionated/accelerated/split vs conventional, disease free survival: two trials (Fu 2000, Olmi 2003); results contradictory with substantial statistical heterogeneity (P = 0.02, I2 = 82%); no pooled estimate…
  2 studies
  GRADE not reported

Accelerated radiotherapy (no split, boost or hyperfractionation) vs Conventional (standard) fractionation radiotherapy

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Accelerated vs conventional, disease free survival: both trials reported this, but substantial clinical and statistical heterogeneity (P = 0.0004, I2 = 92%) meant a pooled analysis was not reported (Analysis 1.3).
  2 studies
  GRADE not reported

Hyperfractionated/accelerated split-course radiotherapy vs Accelerated radiotherapy with concomitant boost

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  Fu 1995: no significant difference in disease free survival; data not presented in a way that allows calculation of an HR.
  1 study · 75 participants
  GRADE not reported

Surgery +/- radiotherapy + (adjuvant) chemotherapy vs Surgery +/- radiotherapy alone (observation or adjuvant radiotherapy only)

Surgery +/- radiotherapy + (adjuvant) chemotherapy led to lower disease-free survival, adjuvant concurrent chemoradiation vs… compared with surgery +/- radiotherapy alone (observation or adjuvant radiotherapy…; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: chemotherapy 2021 · Cochrane All outcomes
  HR 0.84 [0.72, 0.97]
  4 studies
  GRADE not reported

Induction chemotherapy plus locoregional treatment (radiotherapy and/or surgery) vs Locoregional treatment (radiotherapy and/or surgery) alone

Induction chemotherapy plus locoregional treatment (radiotherapy… led to lower disease-free survival, induction platinum + 5-fluorouracil prior to… compared with locoregional treatment (radiotherapy and/or surgery) alone; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: chemotherapy 2021 · Cochrane All outcomes
  HR 0.78 [0.63, 0.97]
  3 studies · 332 participants
  GRADE not reported

Superselective neck dissection vs Elective selective neck dissection

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes

  36 months
  Disease-free survival: Pandey 2018 reported 83% (superselective) vs 91% (selective) at median 36 months, not significant (P=0.69); unable to analyse (variable follow-up); 32 participants (1 RCT).
  1 study · 32 participants
  Very low

Surgery vs Radiotherapy alone

Surgery showed no clear difference in disease-free survival (new disease, progression, and mortality) compared with radiotherapy alone (low certainty).

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes

  3 years
  HR 1.07 [0.27, 4.22]
  1 study · 68 participants
  Low

Sentinel node biopsy (neck dissection only if biopsy positive) vs Elective neck dissection

Sentinel node biopsy (neck dissection only if biopsy positive) showed no clear difference in disease-free survival (new disease, progression, and mortality) compared with elective neck dissection (low certainty).

• Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment 2023 · Cochrane All outcomes

  3 years
  HR 0.98 [0.90, 1.07]
  1 study · 279 participants
  Low