What do systematic reviews say?

Surgery vs Radiotherapy alone

Surgery showed no clear difference in total 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 0.83 [0.09, 7.46]
  1 study · 68 participants
  Low

Pre-operative radiotherapy (plus surgery) vs surgery

Pre-operative radiotherapy (plus surgery) showed no clear difference in total mortality compared with surgery alone; GRADE not reported.

• Interventions for the treatment of oral cavity and oropharyngeal cancer: radiotherapy 2010 · Cochrane All outcomes
  HR 0.83 [0.64, 1.07]
  1 study
  GRADE not reported

Surgery plus radiotherapy vs Radiotherapy alone

It is very uncertain whether surgery plus radiotherapy changes total mortality compared with radiotherapy alone (very low certainty).

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

  3 years
  HR 0.24 [0.10, 0.59]
  1 study · 35 participants
  Very low

Surgery plus radiotherapy vs Chemotherapy (chemoradiotherapy)

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

  oral cavity
  Total mortality: study reported survival significantly better with surgery and RT vs chemoradiotherapy, but no useable data; 32 participants (1 RCT, Iyer 2015 oral cavity subgroup).
  1 study · 32 participants
  Very low

Preoperative radiotherapy vs surgery

Preoperative radiotherapy showed no clear difference in overall mortality ‐ only total mesorectal excision ( compared with surgery alone (low certainty).

• Preoperative radiotherapy and curative surgery for the management of localised rectal carcinoma 2018 · Cochrane Headline outcomes only
  Peto OR 0.97 [0.87, 1.08]
  2 studies · 3211 participants
  Low