Rapid progression of squamous cell carcinoma of the cervix after hyperbaric oxygenation

Hyperbaric oxygen therapy for late radiation-associated tissue necroses: is it safe in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers?

PURPOSE

To test, in a retrospective matched-pair study, whether necrosis-rescuing hyperbaric oxygen therapy (HBOT) increases the risk of cancer re-recurrence in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers.

METHODS AND MATERIALS

Between January 1995 and July 2004, we retrospectively identified 22 patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers. We defined two groups: the HBOT group, 11 patients with HBOT for rescuing late radiation-associated tissue necroses; and the non-HBOT group, the other 11 matched-pair patients without HBOT. Between the two groups, the following four factors were matched for case pairing: primary cancer subsite, initial cancer stage, age, and gender.

RESULTS

Three findings indicate that HBOT increases the risk of cancer re-recurrence. First, we observed more cancer re-recurrences in the HBOT group than in the non-HBOT group: 9 of 11 vs. 4 of 11, with 5-year disease-free survival rates after salvage of 32.7% vs. 70.0% (hazard ratio 3.2; 95% confidence interval 1.03-10.7; p = 0.048). Second, re-recurrences developed rapidly after HBOT in 6 patients. Third, 3 patients had unusual cancer re-recurrences after HBOT. Remarkably, of 9 patients with cancer re-recurrences in the HBOT group, 4 patients had cancer disease-free intervals of 9 months or less before HBOT.

CONCLUSIONS

Necrosis-rescuing HBOT should be given with caution in patients with locoregionally recurrent and then successfully salvaged head-and-neck cancers; if it cannot be omitted entirely, deferring HBOT 9 months or longer after cancer re-treatment may be prudent.

Hyperbaric oxygen therapy for late radiation tissue injury in gynaecological patients

BACKGROUND

Pelvic radiation therapy is an important element of curative therapy for gynaecological cancers. Serious radiation-related complications developing months or years after treatment are known as late radiation tissue injury (LRTI).

METHODS

We investigated the possible pain reducing effect of hyperbaric oxygen treatment (HBOT) in a study of 16 patients with LRTI after radiation for gynaecological malignancy. The 16 patients were registered prospectively, underwent HBOT for 21 consecutive days and were followed for a 6-month period after treatment using the Brief Pain Inventory, Montgomery and Aasberg Depression Rating Scale, as well as registration of global patient scores, analgesic consumption and magnetic resonance imaging (MRI) findings.

RESULTS

HBOT was shown to have insignificant effect on pain, pain characteristics, daily function, the use of analgesics and MRI-related tissue injury. Fifty percent of the patients still reported some or good effect of the treatment.

CONCLUSION

It is not possible to conclude from our study if gynaecological patients with pelvic pain will benefit from HBOT. The application of HBOT to selected patients may be justified, but further research with adequate sample size, as well as the timing of HBOT related to the development of LRTI, is required to establish the optimum patient selection.

Effects of hyperbaric oxygen exposure on experimental head and neck tumor growth, oxygenation, and vasculature

BACKGROUND

Hyperbaric oxygen (HBO2) is used to promote healing in irradiated tissues, but concern persists about the possibility that it may promote residual tumor growth.

METHODS

The tumor growth of SQ20B and Detroit 562 head and neck squamous cell carcinoma xenografts were studied after single-dose irradiation and 5x/week HBO2 treatment at 2.4 atm absolute for 90 minutes. The effect of HBO2 treatment on tumor hypoxia and vasculature was also examined by immunohistochemical analysis.

RESULTS

HBO2 treatment increased tumor oxygenation during the treatment interval but did not promote the growth of either irradiated or unirradiated tumors. No increase in tumor vascular endothelial growth factor expression or vascularization was detected.

CONCLUSIONS

This study found no evidence for persistent changes in tumor microenvironment or tumor growth promotion caused by hyperbaric oxygen exposure.