Evidence Corner: Evidence-based Care for Malignant Wounds

Malignant fungating wounds occur in 5% to 10% of individuals with cancer.¹ They arise “when malignant tumour cells infiltrate and erode through the skin.”² Guidelines for treating these malignant wounds (MW) often lack randomized, clinical trial (RCT) evidence supporting local wound care interventions that meet patients’ physical or psychosocial needs or facilitate healing.³ The rarity of RCTs exploring healing of MWs likely results from their very low expectation of complete closure.¹ Affected patients and their professional and family caregivers rate pain, infection, and odor management among the most important challenges in minimizing distress.^4-6 Though a recently updated Cochrane review³ reminds us that evidence remains insufficient for firm conclusions supporting management of MW, it does cite 2 recent RCTs described herein^7,8 that can serve as “current best evidence”⁹ to inform clinical decisions for alleviating some aspects of these patients’ distress. 

Reference: Kalemikerakis J, Vardaki Z, Fouka G, et al. Comparison of foam dressings with silver versus foam dressings without silver in the care of malodorous malignant fungating wounds. J BUON. 2012;17(3):560–564.

Rationale: Infection, odor, and pain are serious complications of malignant fungating wounds.

Objective: Investigate effectiveness of foam dressings with or without silver to reduce odor and infection in malignant wounds (MWs) of patients in the home setting. 

Methods: A prospective, double-blind randomized, controlled trial (RCT) compared the effects of 4 weeks of topical management with an adhesive or non-adhesive hydrocellular foam primary dressing appropriate to wound area (either 10 cm x 10 cm or 15 cm x 15 cm) and exudate levels, with (n = 13) or without 1 mg/cm² of silver sulfadiazine in the foam layer of the dressing (n = 13). All participants in the study were cared for in the home setting for a MW of the breast (n = 11), head, neck (n = 7) or other parts of the body (n = 8). Wound dressings were changed 2 or 3 times per week and reapplied after cleansing the wound with normal saline and a 10% povidone iodine solution. To avoid artifacts of patient familiarization with the wound odor, health care professionals evaluated MW odor weekly during the 4-week study, as “no change,” “reduction of odor,” or “increased odor.” The primary outcome was percent of subjects with a reduction of odor at the end of the fourth week of treatment.  Statistical significance of the difference between group percentages with reduced odor was tested with a significant value (P ≤ 0.05). 

Results: Malodor decreased for 9 (69.2%) of the patients dressed with the silver sulphadiazine foam dressing compared to 4 (30.8%) of the patients receiving non-silver foam dressings (P = 0.049).

Authors’ Conclusions: Antimicrobial properties of the silver dressings were very useful in reducing MW malodor.  

Reference: Lund-Nielsen B, Adamsen L, Kolmos HJ, Rørth M, Tolver A, Gottrup F.  The effect of honey-coated bandages compared with silver-coated bandages on treatment of malignant wounds — a randomized study. Wound Repair Regen. 2011;19(6):664–670.

Rationale: Malodor and excessive exudate are common problems for cancer patients who have a MW.

Objective: Conduct a prospective RCT comparing the effects of honey- or silver-coated bandages on wound area, cleanliness, malodor, exudation, and wound pain in patients with a MW and advanced-stage cancer.

Methods: Patients at least 18 years of age, with advanced-stage cancer, and a MW were consecutively recruited from oncology units of 10 hospitals in Denmark and randomly assigned to receive primary dressings coated with either manuka honey (n = 34 completing the 4 week study) or nanocrystalline silver (n = 35), during two to three 1.5-hour home-based standard of care visits per week for 28 days. Standard of care consisted of (1) cleansing with faucet water, pH 4.5 medical liquid soap; (2) debriding if needed, with Metzenbaum scissors, tweezers, and non-woven pads; (3) the randomized primary dressing; (4) an adhesive hydrocellular foam secondary dressing; (5) weekly, structured 1-hour psychosocial support dialogues about coping with the illness and the MW; and (6) 20-minute prerecorded relaxation training exercises every other day. The same wound care products were used throughout the 2.5-year data collection follow-up period. After the first 28 days of treatment, the primary author evaluated percent change from baseline open wound area (primary outcome), pain measured using a visual analogue scale (VAS), and malodor (rated as “no or slight” or “moderate or strong”) once weekly. Statistical power calculations based on a pilot sample of 12 subjects determined that 35 patients per group would be needed to detect a clinically important difference of 24.8 cm² between groups with a power of 80% in a 2-sided unpaired t-test using P = 0.05 for significance. As appropriate, Mann-Whitney U, Paired Wilcoxon test, Fisher’s exact tests, and logistic regression tests compared baseline and outcome characteristics over the study. The wound area percent reduction from baseline was analyzed as a square root transformation to maintain variance homogeneity. Light’s kappa statistic was used to test observer agreement among multiple inspections of wound cleanliness before and after the 28-day treatment interval. The patient survival followed for up to 1100 days was analyzed using Kaplan-Meier survival curves, with a log-rank test of the association between percent wound area reduction at 4 weeks and survival time.

Results:  Most patients (88%) were females. Eighty percent had cancer of the breast; 12% of the head and neck; and 8% in other areas. Patients were mainly treated with antineoplastic agents (81%) or antibiotics (16%). Median patient age was 65 years with median wound area 130.9 cm². Wound area, malodor, cleanliness (with moderate interrater agreement), and exudation all improved for both groups during the study. Reduced malodor was the only significant difference (P = 0.036) for the combined groups over time. No significant differences between groups were observed on any outcome measure. Pooled Kaplan-Meier analysis revealed that subjects whose MW reduced in wound area experienced a median survival time of 387 days compared to 134 days for those without 4-week area reduction (P = 0.003).

Authors’ Conclusions: Both honey-coated and silver-coated dressings improved the quality of life for most patients, based on measured wound malodor, wound area, cleanliness, and pain during 4 weeks of treatment. The 4-week percent wound area reduction was significantly associated with longer survival.

Both RCTs described here^7,8 reported significant reductions in MW malodor during 4 weeks of a topical dressing with a silver- or honey-coated wound dressing, with no apparent significant difference between the honey- or silver-coated dressings’ effects on reliable measures of wound healing, cleanliness, odor, or patient-reported pain.⁷ These 2 RCTs offer supporting evidence for the use of honey or silver to reduce MW malodor, one of the more distressing aspects of MW management for patients and their caregivers. The authors of the RCT comparing honey- or silver-coated dressings acknowledged the limitation that their study did not include a non-honey or non-silver control dressing group. They noted that it seemed unethical to do so after their pilot study¹⁰ reported clinically important benefits for patients dressed with a silver dressing as compared to a non-silver dressing used within similar protocols of care. Honey-coated dressings appear to offer a suitable comparator based on their capacity to render a high proportion of wound surfaces bacteria free during 1 week of use as a topical dressing.^11-14 Kalemikerakis et al’s⁸ finding of increased malodor in wounds receiving the same dressing without silver appears to replicate their pilot study.  A search of the National Library of Medicine’s MEDLINE database revealed no better evidence to inform clinical decisions about primary dressings that can reduce the misery of those with a MW. Readers aware of better quality RCTs to address the burden of these wounds, please let me know, so that it can reach these pages in the future. For now, clinicians, patients, and their caregivers who face the challenges of a MW do not have the luxury of waiting for better evidence.

This article was not subject to the WOUNDS peer-review process.