Watson
Combined radiotherapy and hyperbaric oxygen for cervical cancer improved local recurrence rates and survival.
Clinical Bottom Line: 1. Survival was improved with the addition of hyperbaric oxygen. 2. Local tumour control was improved with hyperbaric oxygen. 3. There was no significant effect of hyperbaric oxygen on metastasis rate. Appraised by: Mike Bennett, Dept of Diving and Hyperbaric Medicine, Prince of Wales Hospital, Sydney; Thursday, 07 January, 1999
Clinical Scenario: A patient with locally advanced carcinoma of the cervix where radiotherapy is the preferred treatment modality for control of tumour spread. Three-part Question: In locally invasive carcinoma of the cervix treated with radiotherapy, does the administration of hyperbaric oxygen during irradiation confer any benefit in terms of survival or metastasis-free periods? Search Terms: Hyperbaric oxygenation, radiotherapy, cervix uteri.
The Study: Non-blinded randomised controlled trial with intention-to-treat. Patients under 75 years with advanced carcinoma of the cervix without spread beyond the pelvis. Control group (N = 159; 159 analysed): Standard radiotherapy regime for each centre. Experimental group (N = 161; 161 analysed): As above plus hyperbaric oxygen. Dose not stated.
The Evidence:
| Outcome | Time to Outcome | Air group | HBO group | Relative risk reduction | Absolute risk reduction | NNT |
| Local recurrence | 5 years | 0.53 | 0.33 | 38% | 0.2 | 5 |
| 95% CI: | 18% to 58% | 0.09 to 0.31 | 4 to 11 | |||
| Death | 5 years | 0.73 | 0.67 | 8% | 0.06 | 17 |
| 95% CI: | -6% to 22% | -0.04 to 0.16 | NNT 7 to INF NNH 25 to INF | |||
| Metastasis | 5 years | 0.5 | 0.51 | -2% | -0.01 | -100 |
| 95% CI: | -24% to 20% | -0.12 to 0.1 | NNT 11 to INF NNH 9 to INF |
Non-Event Outcomes Time to outcome/s P-value
- (survival analysis)
Survival Stage III 5 years 0.009 patients Local recurrence free period 5 years <0.001
Comments: 1. Some increase in treatment morbidity in the hyperbaric group (33 pats versus 14 with severe or moderate morbidity). 2. Some evidence that those who benefit most were under 55 years and had Stage III disease. 3. Recurrence-free and mestatstasis-free figures include those deceased by other causes.
- Expiry date: January 2004
- References:
1. Watson ER, Dische S, Cade IS, Wiernik G, Sutherland I. Hyperbaric oxygen and radiotherapy: a medical research council trial in carcinoma of the cervix. British Journal of Radiology 1978; 51:879-887. 2. Wiernik G, Perrins D. Hyperbaric oxygen and radiotherapy in advanced carcinoma of the cervix and bladder. Fifth International Hyperbaric Congress Proceedings II 1974:820-829. 3. Dische S. The hyperbaric oxygen chamber in the radiotherapy of carcinoma of the uterine cervix. British Journal of Radiology 1974; 47:99-107. File:Http://www.hboevidence.com/ themes/copy-of-sumi-painting/sumhorsa.gif
