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PubMed1995

Structural requirements for mitomycin C DNA bonding.

Information of the specific structure of the activated mitomycin species leading to selective DNA bonding has been secured by determining the bonding sequence selectivities of modified mitomycins in which the identity, spatial orientation, and state of unsaturation of the C-9 and C-9a substituents in the mitomycin were varied. Both mitomycin-9a-sulfonate (8) and mitomycin D (9) gave DNA bonding profiles comparable to those obtained for mitomycin C (1) under reductive conditions, indicating that neither the stereochemistry of the C-9 and C-9a substituents nor the identity of the leaving group at C-9a influenced the site(s) of DNA bonding. These results indicated that aromatization of the dihydropyrrole ring in mitomycin C precedes DNA binding and mitomycin C-1 bonding.

Base Sequence↗
PubMed1999

Intraoperative application versus postoperative mitomycin C eye drops in pterygium surgery.

PURPOSE: Postoperative recurrence of pterygium occurs in many patients. Intraoperative and postoperative mitomycin therapy are two adjuvant treatment methods shown to lessen the high pterygium recurrence rate seen with simple excision alone. The authors designed a prospective, randomized study to explore the recurrence rate of pterygium after a single dosage of mitomycin C at the completion of pterygium excision, comparing it to postoperative mitomycin C therapy. METHODS: Thirty-six patients with 40 primary and recurrent pterygia were randomized to 1 of 2 treatment groups: intraoperative mitomycin 0.2 mg/ml for 5 minutes (group 1) and postoperative mitomycin 0.2 mg/ml four times a day for 7 days (group 2). The mean follow-up time was 15 months (range, 6 to 24 months). RESULTS: The pterygium recurred in 3 (15%) of 20 eyes in group 1 and in 4 (20%) of 20 eyes in group 2 (p=0.41). One patient in group 1 had a mild scleral melting (1 x 1 mm) and a delay of reepithelialization for three weeks. Moderate superficial punctate keratitis (two eyes) and mild anterior chamber reaction (one eye) developed in group 2. CONCLUSION: This study indicates possible advantages of administration of a single dosage of 0.02% mitomycin C over postoperative mitomycin therapy. If the decision is made to use adjunctive mitomycin, the authors recommend intraoperative over postoperative administration.

Adult↗
PubMed2002

Mitomycin C in combination with radiotherapy as a potent inhibitor of tumour cell repopulation in a human squamous cell carcinoma.

The potential of Mitomycin C in combination with fractionated irradiation to inhibit tumour cell repopulation of a fast growing squamous cell carcinoma after fractionated radiotherapy was investigated in vivo. A rapidly growing human squamous cell carcinoma (FaDu(dd)) was used for the study. For experiments, NMRI (nu/nu) mice with subcutaneously growing tumours were randomly allocated to no treatment, Mitomycin C, fractionated irradiation (ambient: 11 x 4.5 Gy in 15 days), or fractionated irradiation combined with Mitomycin C. Graded top up doses (clamped blood flow: 0-57 Gy) were given at day 16, 23, 30 or 37. End point of the study was the time to local tumour progression. Data were examined by multiple regression analysis (Cox). Mitomycin C alone resulted in a median time to local tumour progression of 23 (95% confidence limits: 17-43) days, fractionated irradiation in 31 (25-35) days and combined Mitomycin C plus fractionated irradiation in 65 (58-73) days (P=0.02). Mitomycin C decreased the relative risk of local recurrence by 94% (P<<0.001) equivalent to 31.7 Gy top up dose. Repopulation accounted for 1.33 (0.95-1.72) Gy per day top up dose after fractionated irradiation alone and for 0.68 (0.13-1.22) Gy per day after fractionated irradiation+Mitomycin C (P=0.018). Mitomycin C significantly reduces the risk of local recurrence and inhibits tumour cell repopulation in combination with fractionated irradiation in vivo in the tested tumour model.

Animals↗
PubMed2001

Cellular resistance to mitomycin C is associated with overexpression of MDR-1 in a urothelial cancer cell line (MGH-U1).

OBJECTIVE: To compare multidrug resistance (MDR)-1 and MDR-3 gene expression in a new urothelial cancer cell line (MGHU-1, with resistance to mitomycin C) against controls and the established (epirubicin-resistant) MDR clone, and to correlate MDR with cytotoxicity data. MATERIALS AND METHODS: Resistance to mitomycin C was induced by the long-term exposure of wild-type MGHU-1 cells to increasing concentrations (20-400 nmol/L) of mitomycin C. The cytotoxicity of mitomycin C or epirubicin was then compared in MGHU-1, MGHU-MMC (mitomycin C-resistant) and MGHU-1R (established MDR) cells, using the tetrazolium biomass assay. The expression of MDR-1 and -3 was investigated by the reverse transcriptase-polymerase chain reaction, using cDNA-specific primers after titration, and compared with DNA and negative controls. RESULTS: MDR-1 and -3 were significantly and equally overexpressed in MGHU-1R, and associated with a dramatic increase in the 50% inhibitory drug concentration (P < 0.001) for mitomycin C and epirubicin against controls. In MGHU-MMC, the overexpression of MDR-1 was three times greater than that of MDR-3. The cytotoxicity profile for both agents was very similar to that of MGHU-1R. Trace amounts of MDR-1, but not MDR-3, were identified in the MGHU-1 wild-type. CONCLUSIONS: Urothelial cancer cell resistance to mitomycin C is associated with cross-resistance to epirubicin and overexpression of MDR-1, suggesting that mitomycin C falls within the MDR category. Clinical application of this methodology may allow patients to be identified who are unlikely to benefit from intravesical chemotherapy.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2006

Mitomycin C: an alternative conservative treatment for refractory esophageal stricture in children?

BACKGROUND AND STUDY AIMS: Mitomycin C is an antiproliferative agent that has been used successfully as an adjunct treatment in ophthalmological procedures, in the management of laryngeal and tracheal stenosis, and more recently to prevent the recurrence of caustic esophageal strictures in children. The aim of this study was to assess the efficacy and safety of local application of mitomycin C to refractory esophageal strictures in children. PATIENTS AND METHODS: We performed a preliminary prospective study of local application of mitomycin C in four children, aged between 1 year and 6 years, who had refractory esophageal strictures. Two of the children presented with strictures caused by caustic ingestion and the other two children had anastomotic strictures following surgical repair of congenital esophageal atresia. The patients had required between four and ten esophageal dilations over a 5-24-month period before mitomycin C application. After an endoscopic dilation, mitomycin C was applied onto the dilation wound using a rigid endoscope. RESULTS: No complications were observed after the procedure. One child required a second application of mitomycin C 2 weeks after the first application because of recurrence of dysphagia. All the children remained asymptomatic and none of them required further dilation over a mean follow-up period of 24 months. Radiological control examinations revealed that there was no recurrence of the esophageal strictures and esophageal biopsies performed during follow-up showed no signs of dysplasia. CONCLUSIONS: Local application of mitomycin C is a potential alternative to iterative dilations, surgery, or stent placement for the treatment of refractory esophageal strictures in children. However, prospective, long-term assessment of outcomes is needed before any definitive conclusion can be drawn about the usefulness of mitomycin C in these patients.

Administration, Topical↗
PubMed1996

Differential toxicity of mitomycin C and porfiromycin to aerobic and hypoxic Chinese hamster ovary cells overexpressing human NADPH:cytochrome c (P-450) reductase.

Purified NADPH:cytochrome c (P-450) reductase (FpT; NADPH-ferrihemoprotein oxidoreductase, EC 1.6.2.4) can reductively activate mitomycin antibiotics through a one-electron reduction to species that alkylate DNA. To assess the involvement of FpT in the intracellular activation of the mitomycins, transfectants overexpressing a human FpT cDNA were established from a Chinese hamster ovary cell line deficient in dihydrofolate reductase (CHO-K1/dhfr-). The parental cell line was equisensitive to the cytotoxic action of mitomycin C under oxygenated and hypoxic conditions. In contrast, porfiromycin was considerably less cytotoxic to wild-type parental cells than was mitomycin C in air and markedly more cytotoxic under hypoxia. Two FpT-transfected clones were selected that expressed 19- and 27-fold more FpT activity than the parental line. Levels of other oxidoreductases implicated in the activation of the mitomycins were unchanged. Significant increases in sensitivity to mitomycin C and porfiromycin in the two FpT-transfected clones were seen under both oxygenated and hypoxic conditions, with the increases in toxicity being greater under hypoxia than in air. These findings demonstrate that FpT can bioreductively activate the mitomycins in living cells and implicate FpT in the differential aerobic/hypoxic toxicity of the mitomycins.

Aerobiosis↗
PubMed1998

The intracellular location of NADH:cytochrome b5 reductase modulates the cytotoxicity of the mitomycins to Chinese hamster ovary cells.

NADH:cytochrome b5 reductase activates the mitomycins to alkylating intermediates in vitro. To investigate the intracellular role of this enzyme in mitomycin bioactivation, Chinese hamster ovary cell transfectants overexpressing rat NADH:cytochrome b5 reductase were generated. An NADH:cytochrome b5 reductase-transfected clone expressed 9-fold more enzyme than did parental cells; the levels of other mitomycin-activating oxidoreductases were unchanged. Although this enzyme activates the mitomycins in vitro, its overexpression in living cells caused decreases in sensitivity to mitomycin C in air and decreases in sensitivity to porfiromycin under both air and hypoxia. Mitomycin C cytotoxicity under hypoxia was similar to parental cells. Because NADH:cytochrome b5 reductase resides predominantly in the mitochondria of these cells, this enzyme may sequester these drugs in this compartment, thereby decreasing nuclear DNA alkylations and reducing cytotoxicity. A cytosolic form of NADH:cytochrome b5 reductase was generated. Transfectants expressing the cytosolic enzyme were restored to parental line sensitivity to both mitomycin C and porfiromycin in air with marked increases in drug sensitivity under hypoxia. The results implicate NADH:cytochrome b5 reductase in the differential bioactivation of the mitomycins and indicate that the subcellular site of drug activation can have complex effects on drug cytotoxicity.

Animals↗
PubMed1999

Toxic effects of mitomycin-C on cultured corneal keratocytes and endothelial cells.

Improper use of mitomycin-C in ocular medication may result in damage to corneal cells. In this study, the toxic effects of mitomycin-C on cultured porcine keratocytes and endothelial cells were estimated by MTT, 3H-thymidine uptake and cellular counting assay methods. It was found that mitomycin-C caused a dose-dependent toxic effect to keratocytes and endothelial cells. Both cells were treated with mitomycin-C at the concentration ranging from 100, 10, 1, 0.1 to 0.01 microg/ml for 3 min, 5 min or 100 min. The 50% inhibitory dose (ID50) of mitomycin-C to keratocytes and endothelial cells as measured by MTT assay was 0.40, 0.18, 0.16 mg/ml and 0.27, 0.15, 0.14 mg/ml, respectively, after 3, 5 and 100 minutes drug treatment. The ID50 for keratocytes and endothelial cells as measured by 3H-thymidine uptake immediately, 1 day and 7 days after 100 minutes mitomycin-C treatment was 0.3, 0.0002, 143.2 microg/ml and 45.1, 101.1, 450.2 microg/ml, respectively. The ID50 for keratocytes and endothelial cells as measured by cellular counting 1 day and 7 days after mitomycin-C treatment was 232.5, 109.7 microg/ml and 239.9, 367.5 microg/ml, respectively. It is concluded that mitomycin-C is more toxic to cellular proliferation in cultured corneal keratocytes than in endothelial cells.

Animals↗
PubMed2005

Evaluation of mitomycin C in reducing postoperative adhesions in strabismus surgery.

AIMS: The aim of this study was to evaluate the efficacy of mitomycin C in reducing postoperative adhesions following strabismus surgery. METHODS: This study was a prospective, single-center, interventional case series. We randomized 14 patients with restrictive strabismus to the mitomycin C group (7 patients) or to the control group (7 patients). We used mitomycin C intraoperatively for 5 min at a concentration of 0.2 mg/mL in the mitomycin group after adhesion release. We compared postoperative results using the forced duction test. RESULTS: Compared to the control group, the mitomycin C group exhibited a better range of passive duction at all postoperative follow-up times; however, mitomycin C did not completely eliminate the problem of postoperative adhesions. Patients receiving mitomycin C did not report any complications during this study. CONCLUSIONS: The intraoperative application of mitomycin C is a safe and effective adjunct to surgery in the treatment of restrictive strabismus.

Adult↗
PubMed2005

Otologic effects of topical mitomycin C: phase I-evaluation of ototoxicity.

HYPOTHESIS: To determine ototoxicity of topical mitomycin C when placed in the middle ear at varying concentrations. BACKGROUND: Despite meticulous surgical technique and diligent postoperative care, some patients develop excessive scar and granulation tissue in the middle ear or mastoid cavity. Poor wound healing may result in infection, tympanic membrane perforation, or conductive hearing loss, which may necessitate further surgery. Use of topical mitomycin C in the ear may be beneficial in reducing scar and granulation tissue formation. This phase of the study was developed to determine the safety of topical mitomycin C in the rat model relative to ototoxicity. METHODS: Twelve Sprague-Dawley rats were evaluated with auditory brainstem response testing before and after treatments. Topical mitomycin C was injected in the middle ear of the right ear of eight animals. Varying concentrations of 0.125 to 0.5 mg/ml were used. Saline was injected in the left ear of each animal to serve as a control. Four separate animals were evaluated with placement of topical mitomycin C on Gelfoam into the middle ear. In two animals, Gelfoam was placed in the middle ear for 1 minute and then removed. In two animals, Gelfoam was placed in the middle ear and left in place. Auditory brainstem response testing was performed at 4 weeks and at 8 weeks. RESULTS: Using a high concentration of mitomycin C (>0.25 mg/ml) resulted in ototoxicity, with an increase in the auditory brainstem response threshold at 4 weeks and at 8 weeks. At low concentrations (<0.20 mg/ml), no change in auditory brainstem response threshold was noted. Animals treated with Gelfoam soaked in mitomycin C showed no change in auditory brainstem response threshold. CONCLUSION: The results of this study indicate that topical mitomycin C on Gelfoam applied in the middle ear appears safe when low concentrations are used, even in the rat, which has a higher susceptibility to gentamycin toxicity than humans. Higher concentrations may lead to ototoxicity based on changes in Wave V on auditory brainstem response. This treatment may prove to be an important option for patients suffering from chronic granulation tissue or scar tissue in the external or middle ear.

Administration, Topical↗
PubMed2006

Effects of mitomycin-C on normal dermal fibroblasts.

OBJECTIVES: To evaluate the effects of mitomycin-C on the growth and autocrine growth factor production of human dermal fibroblasts from the face. STUDY DESIGN: In vitro study using normal adult dermal fibroblast cell lines in a serum-free model. METHODS: Cell cultures were exposed to 4 mg/mL, 0.4 mg/mL, 0.04 mg/mL, 0.004 mg/mL, and 0.0004 mg/mL concentrations of mitomycin-C solution. Cell counts were performed, and the cell-free supernatants were collected at 0, 1, 3, and 5 days after the initial exposure. Population doubling times were calculated and supernatants were quantitatively assayed for basic fibroblast growth factor (bFGF) and transforming growth factor (TGF)-beta1. RESULTS: Continuous exposure to mitomycin-C caused fibroblast cell death by day 7 at all tested concentrations. A 4 minute exposure to mitomycin-C at 4 mg/mL caused rapid fibroblast cell death. A 4-minute exposure to mitomycin-C at either 0.4 mg/mL or 0.04 mg/mL resulted in decreased fibroblast proliferation. A 4 minute exposure to mitomycin-C at 0.4 mg/mL resulted in a marked increase in the production of both bFGF and TGF-beta1. CONCLUSIONS: A clinically ideal concentration of mitomycin-C would slow fibroblast proliferation yet not cause cell death to allow for a wound healing response. Mitomycin-C 0.4 mg/mL for 4 minutes satisfies the above criteria in vitro.

Adult↗
PubMed1998

Variability of mitomycin C adsorption by activated charcoal.

A saline suspension of mitomycin C adsorbed on activated charcoal and administered intraperitoneally has been reported to be safe and effective in the treatment of gastric carcinoma. Activated charcoal specifically targets tumour and lymph-node tissues and the sustained higher local drug concentration is thought to be beneficial. The charcoal particles used in these suspensions have varied in size from > 147 microm to < 20 nm in diameter, but no data have been published to show how this might affect drug adsorption and delivery. Any variability in drug adsorption could pose a serious clinical risk for drugs with a narrow therapeutic index. We have, therefore, investigated the adsorption of mitomycin C on activated charcoal in-vitro. Activated charcoal was ground and sieved to yield four size-fractions between 180 and 53 microm. Adsorption isotherms (n > or = 3) were constructed and applied to the Freundlich model with 0-l00 microg mL(-1) mitomycin C measured by HPLC with detection at 365 nm. Adsorption of mitomycin C by activated charcoal varied by a factor of three under identical conditions at room temperature (21 degrees C) and at 37 degrees C. The specific adsorption (microg mitomycin C (mg activated charcoal)(-1)) was generally higher at 37 degrees C than at room temperature. The variability of mitomycin C adsorption was greatly reduced by addition of the surface-active agent polyvinylpyrollidone, used to determine that adsorption of mitomycin C was independent of activated charcoal particle size. The characteristics of adsorption of mitomycin C by activated charcoal are complex and should be thoroughly investigated to discover the critical controlling factors before submitting the suspensions for further clinical evaluation.

Adsorption↗
PubMed1997

Mitomycin C dissolved in a reversible thermosetting gel: target tissue concentrations in the rabbit eye.

AIMS: To determine whether a new, reversible thermosetting gel enhances mitomycin C transfer to target ocular tissues in the rabbit eye. METHODS: A 0.1 ml solution of mitomycin C containing 0.22 microgram, 2.9 micrograms, or 28 micrograms of the agent dissolved in a reversible thermosetting gel consisting of methylcellulose, citric acid, and polyethylene glycol was injected subconjunctivally in 30 New Zealand albino rabbits. Scleral and conjunctival tissues were excised at 0.5, 1, 2, 4, or 24 hours after the injection and mitomycin C concentrations in these tissues were determined by high performance liquid chromatography. The concentration over time was approximated to a single exponential curve, and initial mitomycin C concentrations, time constants, and half life values were determined. Finally, the areas under the curves (AUCs) between 0.5 and 24 hours were calculated. RESULTS: The mitomycin C concentrations in the target tissues were dose dependent and decreased rapidly over 24 hours. Both the initial mitomycin C concentrations as well as AUCs in these eyes treated with mitomycin C, dissolved in a reversible thermosetting gel, were higher than those in eyes treated similarly in a previous study in which the gel was not used. CONCLUSION: Applied subconjunctivally in the rabbit eye, mitomycin C dissolved in the reversible thermosetting gel enhanced transfer of the agent to the sclera and the conjunctiva.

Animals↗
PubMed1976

Studies related to antitumor antibiotics. Part V. Reactions of mitomycin C with DNA examined by ethidium fluorescence assay.

The cytotoxic action of the antitumor antibiotic mitomycin C occurs primarily at the level of DNA. Using highly sensitive fluorescence assays which depend on the enhancement of ethidium fluorescence only when it intercalates duplex regions of DNA, three aspects of mitomycin C action on DNA have been studied: (a) cross-linking events, (b) alkylation without necessarily cross-linking, and (c) strand breakage. Cross-linking of DNA is determined by the return of fluorescence after a heat denaturation step at alkaline pH's. Under these conditions denatured DNA gives no fluorescence. The cross-linking was independently confirmed by S1-endonuclease (EC 3.1.4.-) digestion. At relatively high concentrations of mitomycin the suppression of ethidium fluorescence enhancement was shown not to be due to depurination but rather to alkylation, as a result of losses in potential intercalation sites. A linear relationship exists between binding ratio for mitomycin and loss of fluorescence. The proportional decrease in fluorescence with pH strongly suggests that the alkylation is due to the aziridine moiety of the antibiotic under these conditions. A parallel increase in the rate and overall efficiency of covalent cross-linking of DNA with lower pH suggests that the cross-linking event, to which the primary cytotoxic action has been linked, occurs sequentially with alkylation by aziridine and then by carbamate. Mitomycin C, reduced chemically, was shown to induce single strand cleavage as well as monoaklylation and covalent cross-linking in PM2 covalently closed circular DNA. The inhibition of this cleavage by superoxide dismutase (EC 1.15.1.1) and catalase (EC 1.11.1.6), and by free radical scavengers suggests that the degradation of DNA observed to accompany the cytotoxic action of mitomycin C is largely due to the free radical O2. In contrast to the behavior of the antibiotic streptonigrin, mitomycin C does not inactivate the protective enzymes superoxide dismutase or catalase. Lastly, mitomycin C is able to cross-link DNA in the absence of reduction at pH 4. This is consistent with the postulated cross-linking mechansims.

Animals↗
PubMedDate not supplied

Trabeculectomy with mitomycin C versus trabeculectomy alone for juvenile primary open-angle glaucoma.

PURPOSE: We compare the intermediate-term outcome of initial trabeculectomy with adjunctive mitomycin C use versus initial trabeculectomy alone for juvenile primary open-angle glaucoma. METHODS: This retrospective consecutive analysis included 44 eyes from 36 patients with juvenile primary-open angle glaucoma, all of whom underwent either initial trabeculectomy with adjunctive mitomycin C use (15 eyes) or initial trabeculectomy alone without mitomycin C use (29 eyes). We compared the success rate and complications between the two groups in a three-year follow-up period following surgery. RESULTS: Three years subsequent to surgery, the cumulative success probability was 73% for the mitomycin C group and 68% for the control group, there being no real difference between the two groups (p = 0.89). A greater incidence of hypotony maculopathy was found amongst the mitomycin C group than was the case for the control group (20 versus 0%, respectively, p = 0.034). A lower intraocular pressure amongst the mitomycin C group was noted as compared with the control group (10.8 +/- 3.0 versus 13.3 +/- 3.8 mm Hg, respectively, p = 0.017) amongst the successfully treated patients. CONCLUSIONS: Despite the lower intraocular pressure level for the successfully treated patients from the trabeculectomy with mitomycin C group, and a greater incidence of resultant hypotony maculopathy for this group as compared with the trabeculectomy alone group, there appeared to be no significant difference in the cumulative success probability for this group as compared with the trabeculectomy alone group. Therefore, we caution against the use of an initial trabeculectomy with mitomycin C for juvenile primary open-angle glaucoma.

Adolescent↗
PubMed1993

The use of mitomycin in esophageal cancer.

Concurrent administration of chemotherapeutic agents and radiation with or without surgery has yielded better local disease control and more prolonged survival than has standard radiation therapy or surgery alone in patients with esophageal cancer. Combinations of 5-fluorouracil (5-FU) and either cisplatin or mitomycin have proven most effective in this setting. As a single agent, mitomycin has generated response rates of 14-42% in patients with squamous cell carcinoma of the esophagus. The response of patients with esophageal adenocarcinoma to single-agent mitomycin is unknown. The clinical use of mitomycin concurrent with 5-FU and radiation is well established in esophageal cancer. There is some experimental evidence to suggest that synergy may occur between 5-FU and mitomycin. Mitomycin is preferentially cytotoxic to hypoxic cells, which are relatively radioresistant. It is not clear whether use of mitomycin with radiation is additive or supra-additive as experimental evidence exists to support both types of interaction. Nonrandomized clinical trials suggest that using either cisplatin or mitomycin concurrently with 5-FU and relatively low-dose radiation (30 Gy) prior to esophagectomy can result in comparable rates of pathologic complete response (20-30%) and median survival (12-19 months). Hematologic toxicity is frequently severe if all 3 drugs are used concurrently in combination with radiation. In patients with advanced disease (stage III or IV), combination chemotherapy/radiation therapy can result in significant palliation with tolerable morbidity. The use of concurrent chemotherapy and radiation has changed the pattern of failure in esophageal cancer from one dominated by inability to control local disease to one where systemic failure predominates. Current and proposed trials in esophageal cancer have changed their focus accordingly to meet this new treatment challenge.

Adenocarcinoma↗
PubMed1993

Mitomycin in anal canal carcinoma.

One hundred and ten patients with primary epidermoid cancers of the anal canal were treated in a series of prospectively designed, nonrandomized protocols of split-course radiation therapy with concurrent administration of 5-fluorouracil (5-FU) with or without mitomycin. The addition of mitomycin was associated with improved primary tumor control rates (87 vs. 58% at 4 years, p = 0.005) and improved 4-year actuarial cause-specific survival (80 vs. 64%, p = 0.02). Hematologic toxicity was the most frequent acute side effect of mitomycin use. No long-term toxicity was attributed to mitomycin only. Mitomycin appeared to benefit patients principally through improved control of cancer in the irradiated volume; there was no evidence of reduced risk of extrapelvic metastases. Several investigators have reported high rates of control of epidermoid anal cancers with preservation of anorectal function following concurrent treatment with mitomycin, 5-FU, and radiation. Mitomycin's role in anal cancer is being evaluated in a randomized clinical trial by the Radiation Therapy Oncology Group. The mechanisms of any interactions between mitomycin and radiation or other cytotoxic drugs in clinical practice remain to be determined.

Actuarial Analysis↗
PubMed1997

Chemotherapy as an adjunct to radiation in the treatment of squamous cell carcinoma of the head and neck: results of the Yale Mitomycin Randomized Trials.

PURPOSE: Two consecutive randomized trials were run at our institution using the bioreductive alkylating agent mitomycin as an adjunct to radiation therapy in an effort to improve outcome in patients with squamous cell carcinoma of the head and neck. METHODS: Between 1980 and 1992, two consecutive randomized trials using mitomycin (trial 1) and mitomycin with dicumarol (trial 2) as an adjunct to radiation therapy in patients with squamous cell carcinoma of the head and neck were conducted at our institution. The patients were stratified by intent of therapy, extent of disease, and primary tumor site. Within each strata, patients were randomized to receive radiation therapy with or without mitomycin (trial 1) or mitomycin/dicumarol (trial 2). RESULTS: A total of 203 patients were enrolled onto both trials, 195 of whom were eligible for analysis. Patients were equally balanced with respect to sex, age, extent of disease, primary site, radiation dose, and total duration of radiation treatment. Hematologic toxicities were more frequently noted in the drug-treated arms, but were acceptable with no drug-related treatment deaths. Nonhematologic toxicities were acceptable and not significantly different between the two arms. As of September 1995, with a median follow-up of 138 months, a statistically significant benefit occurred in the mitomycin arms with respect to cause-specific survival (0.74 +/- 0.05 v 0.51 +/- 0.05; P = .005), local recurrence-free survival (0.85 +/- 0.04 v 0.66 +/- 0.05; P = .002), and local regional recurrence-free survival (0.76 +/- 0.05 v 0.54 +/- 0.05; P = .003). No statistically significant difference in overall survival was obtained (0.48 +/- 0.05 mitomycin arms v 0.42 +/- 0.05 radiation alone). CONCLUSION: The bioreductive alkylating agent mitomycin is a safe and effective adjunct to radiation therapy in the treatment of squamous cell carcinoma of the head and neck. The statistically and clinically significant improvement in local regional relapse and cause-specific survival obtained support the use of mitomycin as an adjunct to radiation therapy in the management of squamous cell carcinoma of the head and neck.

Adult↗