Validation of a highly sensitive ICP-MS method for the determination of platinum in biofluids: application to clinical pharmacokinetic studies with oxaliplatin.

ELOXATIN (Oxaliplatin) is a novel platinum containing anti-cancer agent with a diaminocyclohexane carrier ligand which has been approved in several major European countries. Clinical studies have demonstrated that the compound exhibits marked activity against colorectal cancers in combination with 5-fluorouracil (5-FU). The aim of this work was to develop and validate a highly sensitive inductively coupled plasma mass spectrometry assay for the determination of oxaliplatin-derived platinum in plasma ultrafiltrate, plasma and whole blood and to apply this technique to clinical pharmacokinetic studies with oxaliplatin. Ultratrace detection of platinum in plasma ultrafiltrate was achieved using ultrasonic nebulisation combined with ICP-MS. This technique allows detection of platinum at the 0.001 microg Pt/ml level in only 100 microl of matrix. Assays in blood and plasma utilised a standard Meinhardt nebuliser and spray chamber, achieving detection limits of 0.1 microg Pt/ml in 100 and 200 microl of matrix, respectively. The assays were validated (accuracy and precision within +/- 15%) over the concentration ranges: 0.001-0.250 microg Pt/ml in plasma ultrafiltrate and 0.1-10 microg Pt/ml for plasma and whole blood. The effect of sample digestion. dilution, long term frozen storage and quantitation in the presence of 5-FU were also investigated and validated. The method was used to monitor platinum exposure following oxaliplatin administration (130 mg/m2) to cancer patients. Following a 2 h i.v. infusion, peak platinum levels declined in a triphasic manner in all blood compartments. Free platinum was detected in plasma ultrafiltrate at low levels (0.001 0.010 microg Pt/ml) for up to 3 weeks. In conclusion, a highly sensitive and specific assay has been developed for the determination of platinum in biofluids. This method enabled characterisation of the long term exposure to platinum in patients following oxaliplatin treatment.

The effect of cimetidine on the pharmacokinetics of epirubicin in patients with advanced breast cancer: preliminary evidence of a potentially common drug interaction.

Epirubicin is known to be metabolized in the liver. Therefore, drugs such as cimetidine, which inhibit the cytochrome P-450 enzyme system or reduce liver blood flow, may reduce the plasma clearance of epirubicin. In a small study, epirubicin 100 mg/m2 every 3 weeks was administered intravenously to eight patients, who also received oral cimetidine (400 mg b.d. for 7 days starting 5 days before chemotherapy) with either the first or second cycles. Epirubicin pharmacokinetics and liver blood flow (idocyanine green clearance) were assessed at each course. The areas under the plasma concentration time curves (AUCs) were used to compare the systemic exposure to epirubicin and its metabolites with each course. The estimated median percentage increase (95% confidence interval CI) in the AUC with cimetidine were: epirubicin 50% (95% CI -18 to 193, epirubicinol 41% (95% CI 1 to 92). Despite the small numbers studied, the increase in the active metabolite epirubicinol was significant (P < 0.05). These changes in exposure were not explained by reduced cytochrome P-450 activity as the 7-deoxy-doxorubicinol aglycone AUC was not reduced (357% increase: 95% CI 17 to 719) or by a decrease in liver blood flow (17% increase: 95% CI -39 to 104). Cimetidine is likely to be coprescribed or self-administered with epirubicin and therefore clinicians should be aware of this potential interaction.

Identification of a multidrug resistance modulator with clinical potential by analysis of synergistic activity in vitro, toxicity in vivo and growth delay in a solid human tumour xenograft.

Circumvention of multidrug resistance in vitro by resistance modulators is well documented but their clinical use may be limited by effects on normal tissues. We have compared four resistance modifiers, both in terms of modulation of doxorubicin sensitivity in vitro and toxicity in vivo, in order to determine whether it is possible to select agents with clinical potential. Verapamil, D-verapamil and quinidine are all maximally active in the multidrug resistant cell line at about 7 microM and are not cytotoxic at this concentration. The tiapamil analogue Ro11-2933 is a highly potent resistance modulator such that at only 2 microM sensitization is greater than is seen with the other modulators at 7 microM. Since the ID50 concentration for Ro11-2933 is 17.7 microM (5-12-fold less than the other modifiers) we have used isobologram analysis to demonstrate that the interaction with doxorubicin is supra-additive and cannot be explained by additive toxicity. This method of analysis also revealed that when resistance modulation is related to the cytotoxicity of the modulator itself, all four modulators show comparable activity. On the other hand, measurement of the acute toxicity in mice of the modulators did reveal differences. The LD10 for verapamil (51 mg/kg) was about one third of that for quinidine (185 mg/kg) and this is consistent with the known maximum tolerated plasma levels in patients. Furthermore, whilst epirubicin alone was unable to reduce the growth rate of a multidrug resistant human tumour xenograft, the addition of quinidine, but not verapamil, at the maximum tolerated dose did do so. D-Verapamil was only about half as toxic as racemic verapamil and this too is consistent with clinical observations. The LD10 for Ro11-2933 (152 mg/kg) was comparable with that for quinidine. In the human tumour xenograft model maximal growth inhibition was observed with the combination of epirubicin and Ro11-2933 (45 mg/kg) and this degree of growth inhibition was comparable to that obtained with epirubicin alone in the drug sensitive xerografts. Ro11-2933 had no measurable effects on the plasma or tumour pharmacokinetics of epirubicin. These results suggest that it is possible to predict the clinical potential of a resistance modulator. Furthermore, Ro11-2933 is a promising agent for use in the clinic since maximal resistance modulation in vivo is observed at about one third of the LD10 dose.

Adequate tumour quinidine levels for multidrug resistance modulation can be achieved in vivo.

The multidrug resistance (MDR) phenotype can be reversed in vitro by a number of agents thought to interact with P-glycoprotein (P-gp). Although plasma levels, adequate for MDR modulation, can be achieved with certain modulators, concern has been expressed that tumour levels may be inadequate due to high plasma protein binding. Mice bearing an MDR-positive human tumour xenograft were injected intraperitoneally with quinidine (150 mg/kg). After 2 h the mean plasma quinidine level was 1.9 micrograms/ml (5.1 mumol/l) and the mean tumour quinidine effective in vitro. Three tumour biopsy specimens were obtained from patients who had received oral quinidine prior to surgery. Plasma and tumour levels were similar and were comparable with those measured in mice. This study should dispel fears of inadequate tumour levels of this and other modulators due to high plasma protein binding and encourage future clinical trials of modulators in MDR-positive human tumours.

Carcinoma of the male breast: a review of 41 cases.

We reviewed the cases of 41 consecutive men treated for breast carcinoma from 1950 through 1987 at Vanderbilt University Affiliated Hospitals to examine controversies in and methods of therapy for this disease. Twenty-two patients (52%) had stage I or II lesions potentially curable by operative therapy. The overall 5-year survival rates were 100% for stage I, 65% for stage II, 56% for stage III, and 0% for stage IV. Radical mastectomy offered no advantage over modified radical mastectomy in terms of survival or rate of recurrence. Diagnosis at an early clinical stage and no finding of disease in axillary lymph nodes were important factors in survival in this series of patients. All tumors evaluated for hormone receptors were positive. Although experience was limited, encouraging results were obtained with the use of tamoxifen citrate in adjuvant as well as palliative roles. With the exception of a predominance of centrally located lesions and a uniquely high frequency of positive hormone receptor status, carcinoma of the male breast appears biologically similar to the disease in women, and treatment should be guided by similar principles.

Distribution of doxorubicin to normal breast and tumour tissue in patients undergoing mastectomy.

Response to cytotoxic agents is assumed to be related to the concentration of drug achieved within tumour tissue. It is also often assumed that, given similar tissue concentrations of drug, normal tissues are less responsive to the same cytotoxic agents. This can partly be explained by the number of cells in normal tissues that are differentiated. These non dividing cells, in a stable testing phase of the cell cycle (G0) are less susceptible to cytotoxic damage. Little is actually known about the relationship between tumour drug concentrations and those in the tissue of the tumour-bearing organ. In this study, we compared doxorubicin concentrations in paired samples of tumour and normal breast tissue from 17 previously untreated women undergoing mastectomy. The relative cellularities of both specimens were estimated by measuring their DNA content. There was wide variation in intra-tumoural doxorubicin concentrations (range, 220-1,590 ng/g). Normal tissue also showed marked inter-patient variation (range, 81-1,000 ng/g). For a single patient the tumour drug concentrations were significantly higher than those in normal breast tissue (P less than 0.05), and tumour: normal tissue ratios ranged from 1.27 to 8.30. Where doxorubicin concentration was expressed in terms of the relative cellularity of the tissues, there was no significant difference between, drug concentrations in the tumour and those in normal breast tissue (tumour: normal ratios, 1.1:1.8). There was a significant correlation (r = 0.76, P less than 0.05) between peak serum values and tumour concentrations of drug. No correlation was found between drug concentrations achieved and the histological grade or oestrogen receptor status of the breast cancer.

Surgical management of anorectal fistulas in Crohn's disease.

A retrospective review of patients with Crohn's disease treated at our institution from 1973 to 1986 revealed 35 patients operated upon for anorectal fistulas. Twenty-nine had low intermuscular fistulas (multiple in seven), and six had high intermuscular (supralevator) fistulas. Fistulotomy alone was performed in 19 patients, and eight underwent partial fistulotomy and seton insertion. Five additional patients had proximal fecal diversion before fistulotomy. Three patients with severe colonic and anorectal disease underwent proctocolectomy as the initial procedure. Of the 32 patients who had fistulotomy performed, complete healing occurred in 30. Seven patients who healed required more than one operation for fistula. One patient was left with an asymptomatic fistula, and one required proctectomy for persistent symptomatic fistula and proctitis. Success of operation correlated with absence of rectal disease and quiescent disease elsewhere in the gastrointestinal tract. Aggressive medical treatment is required to control bowel disease preoperatively. In the majority of patients, subsequent surgery is justified and healing can be anticipated.

Results of operation for rectovaginal fistula in Crohn's disease.

A retrospective review of patients with Crohn's disease treated at our institution from 1973 to 1986 revealed 12 patients operated on for rectovaginal fistula. Disease involved the large intestine in 10 patients. Primary fistula repair was performed in four patients and four others had staged repair with preliminary fecal diversion. Four patients with severe colonic and anorectal disease had proctocolectomy performed as the first procedure. Of eight patients who underwent fistula repair, complete healing occurred in six. One patient has a persistent fistula, which is minimally symptomatic, and the other required proctocolectomy after three unsuccessful repairs. Success of operation correlated with quiescent intestinal disease and absence of rectal involvement. In selected patients with symptomatic fistulas, surgical repair is indicated and healing can be anticipated.

Perianal lymphoma as a manifestation of the acquired immune deficiency syndrome. Report of a case.

A case of nonHodgkin's lymphoma of the perianal region in a patient with AIDS is reported. The unusual features of AIDS-related lymphoma and the possible role of immunodeficiency increasing susceptibility to oncogenic viruses are discussed.

Pancreatoduodenectomy with pyloric preservation for carcinoma of the pancreas: a cautionary note.

Radical pancreatoduodenectomy for treatment of pancreatic carcinoma has been the surgical standard of care for the past four decades. The recent popularization of pylorus-sparing pancreatoduodenectomy to treat benign pancreatic disease, because of its decreased morbidity and long-term nutritional consequences, has led to the use of this procedure in cases of pancreatic carcinoma. We report recent experience with three patients with pancreatic carcinoma in whom pyloric preservation would have compromised the potential chance for curative resection or compromised palliation because of occult spread of tumor to a region not resected with this new operative approach. Two patients had proximal, microscopic intramural spread of pancreatic adenocarcinoma within the duodenum or antrum--a mode of spread not previously reported with pancreatic carcinoma. Both patients had no other evidence of metastatic involvement, and both would have had positive surgical margins in a pylorus-sparing pancreatoduodenectomy. A third case demonstrates a true submucosal recurrence of pancreatic carcinoma after a pylorus-sparing pancreatoduodenectomy. It is debatable that any case demonstrating intramural spread within the duodenum could be cured with a standard Whipple resection as this may well represent another sign of incurability, like lymphatic or perineural spread, but it is clearly a major potential obstacle to palliation if submucosal recurrences occur as a result of the use of the pylorus-sparing pancreatoduodenectomy in cases of pancreatic cancer. The use of pylorus-sparing pancreatoduodenectomy in resectable pancreatic cancers must be viewed skeptically at this time.

Preoperative colonoscopic diagnosis of villous adenoma of the appendix. Report of a case and review of the literature.

This case of villous adenoma of the appendix reported is unique by virtue of its having been diagnosed preoperatively using colonoscopy. Only 45 such lesions have been described previously, and a review of those cases reveals that 93 percent were discovered at appendectomy performed either incidentally or for acute appendicitis. The malignant potential of this entity is unknown and its treatment is controversial. Because of a report association between adenomas of the appendix and other gastrointestinal neoplasms, long-term surveillance is recommended.

Malignant melanoma of the esophagus.

We have presented a case of malignant melanoma of the esophagus, which appeared to be a primary neoplasm. Characteristic clinical, histologic, and ultrastructural features are described. This lesion should be suspected clinically when a polypoid mass is found in the esophagus, even in the absence of pigmentation.

Comparative cardiotoxicity and antitumour activity of doxorubicin (adriamycin) and 4'-deoxydoxorubicin and the relationship to in vivo disposition and metabolism in the target tissues.

4'-Deoxydoxorubicin (4'-DOX) is an analogue of the anticancer drug Adriamycin (ADR) believed to lack its cardiotoxicity. Bioreduction to a semi-quinone free radical has been implicated in the etiology of ADR induced cardiotoxicity. We have studied (in a rat model) acute cardiotoxicity (after 16 mg/kg i.v. of both drugs), antitumour activity (after 5 mg/kg i.v.) and the relationship to disposition and metabolism in the target tissues (after 5 mg/kg i.v.). 7-Deoxyaglycones, which are considered inactive lipophilic metabolites derived from ADR semi-quinone, were utilised as markers of in vivo tissue free radical generation. Both drugs produced toxicity of equal severity to hearts after 24 hr, associated with high cardiac levels of 7-deoxyaglycones in the case of ADR (AUC0-48 hr, micrograms/g X hr: ADR, 47; ADR 7-deoxyaglycone (ADR-DONE), 24; and adriamycinol 7-deoxyaglycone (AOL-DONE), 35) compared to low cardiac levels of 7-deoxyaglycones but a times five higher peak cardiac concentration of parent drug in the case of 4'-DOX (AUC0-48 hr, micrograms/g X hr: 4'-DOX, 68; 4'-DOX-DONE, 3.8; and 4'-DOL-DONE, 0.8). 4'-DOX displayed superior antitumour activity to ADR against the MC 40A sarcoma growing sub-cutaneously, achieving higher concentrations of parent drug in tumour (AUC0-48 hr, micrograms/g X hr: 4'-DOX, 150; ADR, 60). There was an absence of 7-deoxyaglycones of both drugs in the tumour. These data suggest that drug bioreduction is involved principally only in ADR induced cardiotoxicity and that the level of unchanged parent drug achieved in the tumour is the most important pharmacokinetic determinant of antitumour activity for both ADR and 4'-DOX.

Granular cell tumors.

A lesion of unknown etiology and histogenesis, the granular cell tumor usually arises in the skin or soft tissue. It has been reported, however, in other sites and can be multifocal. The authors have seen 31 such tumors in 26 patients in their institutions since 1970. Most (21) patients were females, and 12 patients were black. The average age was 41.8 years, excluding two newborns with a congenital granular cell myoblastoma of the gingiva. The most common site of occurrence was the skin; seven tumors originated from the trunk and five from the extremities. Four lesions were found in the breast, three on the vulva, two in the axilla, two in the gum, two in the buccal cavity, two in the esophagus, and one each in the stomach, gluteus muscle, eyelid, and bronchus. Two patients had multiple synchronous lesions. These were bilateral hand lesions in one patient, and lesions of the breast and axilla in the other. A third patient had three separate lesions which arose over the course of 5 years, involving the bronchus, the gluteus muscle, and the buccal mucosa. An additional esophageal lesion was an incidental finding 3 years after excision of a granular cell tumor of the breast. All of the tumors were removed with local, simple excision, except for the 2-cm lesion in the stomach for which a wedge resection of the fundus was necessary and the bronchial lesion for which a wedge resection of the left upper lobe of the lung was performed.(ABSTRACT TRUNCATED AT 250 WORDS)

Determination of anthracycline purity in patient samples and identification of in vitro chemical reduction products by application of a multi-diode array high-speed spectrophotometric detector.

We describe the application of a high-speed spectrophotometric detector and high-performance liquid chromatography to the determination of anthracycline purity in extracted patient specimens and to the identification of chemical reduction products. Blood contained pure anthracyclines whilst in urine, tissue and tumour there was evidence of co-eluting endogenous peaks and complexation. Aerobic reduction yielded two main products: a C13 alcohol and a fully reduced, non-fluorescent, yellow hydroquinone. Anaerobic reduction in the presence of DNA yielded a 7-deoxyaglycone metabolite end product instead of the fully reduced hydroquinone. Eight other separate chromatographic species were identified, all of which showed unique absorbance characteristics, having a visible lambda max at 530 nm and being coloured purple/blue.

The effect of verapamil on the pharmacokinetics of adriamycin.

The concurrent administration of adriamycin (intravenous) and verapamil (oral) is of considerable interest because of experimental data suggesting that resistance to adriamycin may be overcome by this means. The potential for a pharmacokinetic interaction between the two drugs has therefore been investigated in five patients with small cell lung cancer treated with combination chemotherapy comprising adriamycin, VP16, vincristine and cyclophosphamide. The data indicate that a significant interaction takes place. Adriamycin peak levels, terminal half-life and the volume of distribution at steady state are higher, whereas plasma drug clearance and the volume of the central compartment are lower with co-administration of verapamil. There was no evidence of enhanced drug toxicity in this study; however, the data should be considered in the interpretation of clinical trials in which adriamycin and verapamil are used together, both in terms of toxicity and tumour response.

Non-diabetic necrobiosis lipoidica. Hitherto unrecognized papulonecrotic, nodulo-ulcerative and familial forms of the disease.

Necrobiosis lipoidica of the legs, in which deep ulcers resembling erythema induratum, gummas or a variety of other chronic progressive ulcerating skin diseases occur, is described. In 2 cases the lesions were precipitated by a crush injury elsewhere in the same leg, but not at the site of the ultimate lesions. In 2 further pairs of siblings the same problem arose as a familial complaint without trauma. These cases were distinguished by severe necrosis in the absence of diabetes.

Familial chronic mucocutaneous candidiasis successfully treated with oral ketoconazole.

A father and son, both suffering from chronic mucocutaneous candidiasis, were successfully treated with oral ketoconazole, a water-soluble imidazole compound. No toxic side-effects occurred during treatment. Treatment was given for about 8 months with diminishing does of ketoconazole. The disease cleared completely about half-way through the course of treatment and did not relapse within 1 month of discontinuing the drug. The only immunological abnormality was a depression in vitro of neutrophil chemotaxis. This became normal during therapy and was regarded as being a result of the disease and not as its cause.