INTRODUCTION
Mitomycin C (MMC) is an antineoplastic antibiotic. It
is derived from the Streptomyces caespitosus bacterium,
and functions as an antiproliferative agent,
inhibiting DNA synthesis by cross-linking the strands of the
double helix.1 Recently, MMC has been used as an alternative
topical and intralesional agent in the approach to hypertrophic
scars and keloids. There is wide variability in the mode of usage
and the success of this agent in the literature, and no large trials
have been conducted regarding scars. Herein, we report a case,
discussing our experience with MMC, and we review the prior
usage of MMC in scar treatment.
CASE REPORT
A 27-year-old Caucasian female with a history of systemic lupus
erythematosus (not on systemic medications) presented large
and painful sternal keloids, recurring after two prior excisions
despite treatment with intralesional triamcinolone, 5-fluorouracil,
topical imiquimod, topical silicone gel, and pulsed-dye laser.
The patient’s superior sternal keloid was re-excised, and in light
of the patient’s unfavorable response to other agents, MMC
was used adjunctively. The skin was extensively undermined to
a distance of at least 3 cm on either edge of the wound. Intraoperatively
MMC (0.4 mg/ml; total of 50 ml soaked on gauze) was
placed on the wound edges for a period of four minutes and
then the treated area was irrigated with saline. The wound was
sutured with polyglycaprone and polydioxanone intradermal
sutures. 6-0 fast-acting gut cuticular sutures were used.
Thereafter, the patient underwent pulsed-dye laser treatments
at 2-month intervals. She tried to keep as much strain
off the wound as possible, bending her shoulders forward in
the post-operative period. Six months following the excision
she remained asymptomatic, with marked improvement of
the area that was excised. She also noted that at the superior
edge of her inferior sternal keloid had "attened, which
she attributed to the MMC application (Figure 2). At this point,
the inferior sternal keloid was excised and treated in a similar
manner with MMC intraoperatively.
DISCUSSION
Several in vitro and animal studies have attempted to characterize
the effect of MMC on the healing wound.1-3 Gray et al
indicated that MMC delays wound healing by down-regulating
the production of extracellular matrix proteins.2 They concluded
that if MMC is applied to the wound before the genetic
induction of a proliferative phenotype (ie, without delay after
surgery), it may be effective at inhibiting !broblast proliferation
and consequent healing.
In an initial trial using MMC for the prevention of keloid recurrence
postoperatively, Talmi et al conducted eight keloid
excisions and placed a saturated pledget with MMC over the
wound prior to closure for 5 minutes.4 A concentration of 0.4 mg/
ml was used. The patients were followed monthly for six months
and again at 14 months. The authors stated that all patients improved
and there were no adverse effects. They indicated that
in all cases, scar thickness was substantially reduced, although
only 2/8 keloids showed complete remission. A limitation of
this small study was the lack of controls. Stewart et al provided
similar results using a 0.4 mg/5 ml concentration of MMC intraoperatively,
reporting a 90% success rate and no recurrences at
follow-up intervals ranging from 6-14 months.5 Again, no controls
were used. Soon after, Sanders et al performed a study
with the same concentration of MMC and the same time frame
for topical application in patients with multiple keloids who
served as their own controls.6 The authors excised 30 keloids
in 15 patients. Excision was followed by intralesional corticosteroid
injection at monthly intervals for 6 months, though this
