Mitomycin B

Two studies compared the success of filtration surgery in high-risk eyes using postoperative 5-FU and mitomycin-C, and found that IOPs are lower, and fewer postoperative glaucoma medications are required for control in eyes treated with mitomycin. A similar number of complications occurred in both groups except for a higher incidence of corneal toxicity in the 5-FU treated eyes. Mitomycin-C offers the additional convenience of a single intraoperative application. 5-FU also may be used as an intraoperative application, but no studies have been published regarding its comparable efficacy or safety compared with mitomycin-C. 5-FU has the advantage of being able to use it at any time in the early postoperative course when bleb inflammation arises. 5-FU has known complications, while mitomycin-C, although it appears relatively safe, has been used in fewer patients so far. The advantage of greater surgical success, with lower intraocular pressures, puts antimetabolites into the armamentarium of every surgeon who performs glaucoma procedures.

Objective:To investigate the ultrastructural and physiologic effects of exposure of the human corneal endothelium to mitomycin at concentrations of 20 micrograms/mL and 200 micrograms/mL using electron microscopy and in vitro specular perfusion techniques.Methods:Four pairs of corneas (with one cornea of each pair receiving balanced salt solution [BSS Plus, Alcon Laboratories, Fort Worth, Tex] and the other receiving BSS Plus with 20 micrograms/mL of mitomycin) suitable for transplantation, except for extremes of age or systemic disease, underwent perfusion with corneal thickness measured serially every 15 minutes followed by fixation for electron microscopy. Mean corneal swelling rate was calculated for all four experiments, and the control group that received BSS Plus was compared with the group that received mitomycin using a paired t test. Electron micrographs were examined in a masked fashion. Similar studies were performed using two pairs of corneas that received 200 micrograms/mL of mitomycin.Results:The mean swelling rate for corneas perfused with 20 micrograms/mL of mitomycin (-4.1 microns/h) was not significantly different from that seen in tissue perfused with BSS Plus (-4.2 microns/h). No consistent ultrastructural changes could be attributed to exposure to 20 micrograms/mL of mitomycin. Perfusions of mitomycin at 200 micrograms/mL resulted in prompt corneal swelling with marked ultrastructural alterations compared with tissue perfused with BSS Plus.Conclusion:Human corneal endothelium may be exposed to undiluted (200 to 500 micrograms/mL) mitomycin with inadvertent entry into the anterior chamber during dissection of the scleral flap bed in trabeculectomy followed by application of mitomycin. This will result in prompt destruction of the endothelium. Exposure to 20 micrograms/mL of mitomycin, a level exceeding the concentration that may be present in the aqueous humor after its proper application, appears nontoxic in this system.

Irinotecan and mitomycin (Mutamycin) possess significant single-agent activity against several tumor types, and mitomycin activates topoisomerase I, the cellular target of irinotecan. We conducted a phase I dose-escalation study of irinotecan and mitomycin in 37 evaluable patients with solid tumors. Antitumor responses included 2 complete responses, 5 partial responses, 10 minor responses, and a CA 19-9 tumor marker response. Responders included 14 patients previously treated with chemotherapy for metastatic disease. No pharmacokinetic interaction between mitomycin and irinotecan was apparent when these agents were given 24 hours apart. Responders (complete and partial responses) demonstrated the largest topoisomerase I induction 24 hours following mitomycin infusion. In addition, since maximum topoisomerase I up-regulation was reached 24 hours after administration of mitomycin, a delay in the administration of irinotecan after mitomycin appeared justified. Based on these encouraging phase I data, phase II clinical trials in breast and esophageal/gastroesophageal junction adenocarcinomas at the recommended doses and schedule are under way.

Intravesical chemotherapy instillation is a unique method of treatment confined to urothelial neoplasia. Within the last decades, the substances Bacillus Calmette-Guerin (BCG) and mitomycin C (MMC) have evolved as the standard regimens for intravesical therapy. However, there are other chemotherapeutic substances, which are used less frequently, such as gemcitabine. In this article we aim to highlight the clinical relevance of intravesical gemcitabine instillations as treatment of non-muscle invasive bladder cancer.The histological subtypes of bladder tumours are as diverse as the intravesical regimens. Inverted papilloma is a rare entity in the spectrum of urological diseases. There seems to be an association with non-muscle invasive bladder cancer.We report a rare case of an inverted bladder papilloma treated with intravesical gemcitabine instillations after BCG failure and an allergic reaction to MMC.