33% hydrogen peroxide as a Neoadjuvant treatment in the surgical excision of non-melanoma skin cancers: a case series

Background

Hydrogen peroxide (H₂O₂) is a product of respiration in mitochondria and an important oxidizing agent in biological systems. Previous investigations have shown the efficacy of H₂O₂ in treating skin conditions such as seborrheic keratosis and actinic keratosis. In an area like the face, reconstruction of excision defects and ultimately aesthetic outcomes are of utmost importance. Hydrogen peroxide may represent a simple yet effective method at shrinking non-melanoma skin cancers (NMSC) of the head and neck before they are excised.

Methods

Eleven consecutive patients presenting to our cutaneous malignancy clinic had their skin lesions evaluated by the senior author for participation in the study. Lesion length and width was measured. Hydrogen peroxide formulated at a concentration of 33% was rubbed into the lesion until blanching was observed. Lesions were re-measured at follow up. Excisional biopsy was then performed and histopathological diagnosis was obtained. Statistical analyses compared pre- and post-treatment lesion dimensions.

Results

Seventeen biopsy-proven NMSC lesions were included in this investigation. Statistically significant reductions in the length (p < 0.001) and width (p < 0.001) were observed with H₂O₂ treatment. For some lesions, H₂O₂ was the sole treatment required, with post-treatment biopsy demonstrating no evidence of malignancy. Patients endured minimal discomfort during treatment and no long-term side effects were observed. Follow up at 6 months revealed no recurrences.

Conclusions

We have demonstrated a significant reduction in the size of multiple lesions after application of 33% hydrogen peroxide, simplifying definitive excision and reconstruction. Hydrogen peroxide demonstrated an ability to successfully treat non-melanoma skin cancers as well.

The impact of seasonal operating room closures on wait times for oral cancer surgery

Background

Operating room slowdowns occur at specific intervals in the year as a cost-saving measure. We aim to investigate the impact of these slowdowns on the care of oral cavity cancer patients at a Canadian tertiary care centre.

Methods

A total of 585 oral cavity cancer patients seen between 1999 and 2015 at the London Health Science Centre (lhsc) Head and Neck Multidisciplinary Clinic were included in this study. Operating room hours and patient load from 2006 to 2014 were calculated. Our primary endpoint was the wait time from consultation to definitive surgery. Exposure variables were defined according to wait time intervals occurring during time periods with reduced operating room hours.

Results

Overall case volume rose significantly from 2006 to 2014 (p < 0.001), while operating room hours remained stable (p = 0.555). Patient wait times for surgery increased from 16.3 days prior to 2003 to 25.5 days in 2015 (p = 0.008). Significant variability in operating room hours was observed by month, with lowest reported for July and August (p = 0.002). The greater the exposure to these months, the more likely patients were to wait longer than 28 days for surgery (odds ratio per day [or]: 1.07, 95% confidence interval [ci]: 1.05 to 1.10, p < 0.001). Individuals seen in consultation preceding a month with below average operating room hours had a higher risk of disease recurrence and/or death (hazard ratio [hr]: 1.59, 95% ci: 1.10 to 2.30, p = 0.014).

Conclusions

Scheduled reductions in available operating room hours contribute to prolonged wait times and higher disease recurrence. Further work is needed to identify strategies maximizing efficient use of health care resources without negatively affecting patient outcomes.

The epidemic of human papillomavirus and oropharyngeal cancer in a Canadian population

BACKGROUND

Sexually transmitted infection with the human papillomavirus (hpv) is responsible for a significant burden of human cancers involving the cervix, anogenital tract, and oropharynx. Studies in the United States and Europe have demonstrated an alarming increase in the frequency of hpv-positive oropharyngeal cancer, but the same direct evidence does not exist in Canada.

METHODS

Using the London Health Sciences Centre pathology database, we identified tonsillar cancers diagnosed between 1993 and 2011. Real-time polymerase chain reaction was then used on pre-treatment primary-site biopsy samples to test for dna from the high-risk hpv types 16 and 18. The study cohort was divided into three time periods: 1993-1999, 2000-2005, and 2006-2011.

RESULTS

Of 160 tumour samples identified, 91 (57%) were positive for hpv 16. The total number of tonsillar cancers significantly increased from 1993-1999 to 2006-2011 (32 vs. 68), and the proportion of cases that were hpv-positive substantially increased (25% vs. 62%, p < 0.002). Those changes were associated with a marked improvement in 5-year overall survival (39% in 1993-1999 vs. 84% in 2006-2011, p < 0.001). When all factors were included in a multivariable model, only hpv status predicted treatment outcome.

INTERPRETATION

The present study is the first to provide direct evidence that hpv-related oropharyngeal cancer is increasing in incidence in a Canadian population. Given the long lag time between hpv infection and clinically apparent malignancy, oropharyngeal cancer will be a significant clinical problem for the foreseeable future despite vaccination efforts.