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.
