A Cochrane review assessed 89 CTs (n= 16 767) of first line chemotherapy additional to locoregional therapies (surgery and/or radiotherapy) for oral cavity or oropharyngeal cancer. In 16 trials all patients and in the remaining studies at least 50% of patients had primary oral or oropharyngeal squamous cell carcinoma.
Induction chemotherapy (25 trials) showed no significant improvement in the primary outcome, overall survival (HR 0.92, 95% CI 0.84 to 1.00 for death) compared to locoregional therapy alone. Eight of these trials reported significant improvement in disease free survival (HR 0.78, 95% CI 0.67 to 0.90). In ten trials assessing the effect of adjuvant chemotherapy after locoregional treatment, there was a significant improvement in overall survival (OS; HR 0.88, 95% CI 0.79 to 0.99). Concomitant chemoradiotherapy compared to radiotherapy alone after surgery (4 trials) resulted in even better OS (HR 0.84, 95% CI 0.72 to 0.98 for death). A comparison of chemoradiation versus radiotherapy alone for patients with non-resectable tumours (25 trials) showed a significant improvement of 21 % (HR 0.79, 95% CI 0.74 to 0.84).
| Timing of chemotherapy | No of trials | Total mortality (HR for death) |
|---|---|---|
| Induction chemotherapy | 25 | HR 0.92, (95% CI 0.84 to 1.00) |
| Adjuvant chemotherapy | 10 | HR 0.88, (95% CI 0.79 to 0.99) |
| Concomitant chemoradiotherapy | 25 | HR 0.79, (95% CI 0.74 to 0.84) |
Comment: The quality of evidence is downgraded by study quality (lack of blinding or blinded outcome assessment).