A retrospective analysis of Hickman line-associated complications in patients with solid tumours undergoing infusional chemotherapy

We present a retrospective analysis of Hickman line use and associated complications in patients with solid tumours undergoing treatment with infusional chemotherapy. One hundred and ten lines were inserted in 94 patients (55 females and 39 males, median age 51), of whom 107 were placed under radiological screening, the remainder by a surgical approach. Catheters were in situ for a total of 9670 days (median 101 days, range 1-278). Fifty-five complications occurred during the lifespan of 39 catheters (35.5%), giving an overall complication rate of 4.03/1000 catheter days. Early complications included pneumothorax (4%), arterial puncture (1%) and failure of placement (1%). Late complications included sepsis (superficial and systemic) (24.5%), venous thrombosis (9%), line displacement (10%) and catheter blockage (1%). Fifteen episodes of systemic sepsis occurred in 12 patients, giving an overall sepsis rate of 1.55/1000 catheter days, while complications requiring catheter removal occurred in 20 cases (18% of insertions, 2.07/1000 catheter days). We conclude that the use of Hickman catheters as a means of long-term venous access in infusional chemotherapy patients is generally safe, but is associated with significant morbidity.

Comprehensive method of analyzing the results of photoastigmatic refractive keratectomy for the treatment of post-cataract myopic anisometropia

PURPOSE

To assess the efficacy, stability, and safety of photoastigmatic refractive keratectomy (PARK) in treating post-cataract myopic anisometropia to restore binocularity and to describe a comprehensive method for analyzing the results of refractive surgery.

SETTING

St. Paul's Eye Center, Royal Liverpool Hospital, Liverpool, United Kingdom.

METHODS

Nineteen patients (20 eyes) with post-cataract myopic anisometropia were treated with PARK using a VISX Twenty-Twenty laser and followed for 12 months. Cataract surgery had been performed between 10 and 144 months (mean 43.4 months) previously. A comprehensive method based on Long's matrix formalism and the vech operator of Harris, in addition to the nearest equivalent sphere and cylinder, was used to analyze the refractive data.

RESULTS

The mean preoperative refraction in the post-cataract eyes was -4.79 +1.17 x 0.2 and in the fellow eyes, +0.02 +0.31 x 166. Twelve months after PARK, the postoperative refraction in the post-cataract eyes was -0.90 +0.65 x 2, a significant reduction (P = .15). This postoperative refraction was not significantly different from that in the fellow eye (P = .93). The pretreatment mean uncorrected visual acuity was 0.12. It improved to 0.41 at 12 months, at which time 52% of eyes achieved a visual acuity of 0.5 or better without correction. All patients regained binocularity. At 12 months, 2 eyes (11%) showed clinically unacceptable regression; 1 eye with grade 2 haze lost 1 line of corrected visual acuity.

CONCLUSIONS

Photoastigmatic refractive keratectomy reduced post-cataract myopic anisometropia, allowing restoration of binocularity in all patients. Overall, the results in this elderly population with previous ocular surgery, posterior capsule thickening, and macular degeneration are not as satisfactory as those obtained from similar treatment of physiological myopia. Stability and postoperative complications are acceptable.

Recurrent squamous-cell carcinoma of the head and neck: overview of current therapy and future prospects

Locoregional recurrence is the most common cause of failure after head and neck cancer surgery. It is a disease which causes significant morbidity especially on speech and swallowing. There are many different treatments available including surgery, reirradiation and chemotherapy. However, none of these have produced any significant survival benefit. Because of this, there has been considerable interest in the development of new biological therapies such as gene therapy and immunotherapy for this disease. The objectives of this article are to provide an overview of the currently available therapies for recurrent head and neck cancer including gene therapy and immunotherapy. Prevention of recurrent disease by the detection and treatment of minimal residual disease is also discussed.

p53 alterations in recurrent squamous cell cancer of the head and neck refractory to radiotherapy

The aim of the study was to determine the incidence of p53 alterations by mutation, deletion or inactivation by mdm2 or human papillomavirus (HPV) infection in recurrent squamous cell cancer of the head and neck (SCCHN) refractory to radiotherapy. Twenty-two tumours were studied. The p53 status of each tumour was analysed by sequencing of exons 4-9 and by immunohistochemistry. Mdm2 expression was assessed by immunohistochemistry and HPV infection was assessed by polymerase chain reaction of tumour DNA for HPV 16, 18 and 33. Fifteen (68%) of the 22 tumours studied had p53 mutations, while seven had wild-type p53 sequence. p53 immunohistochemistry correlated with the type of mutation. HPV DNA was detected in 8 (36%) tumours and all were of serotype HPV 16. Of these, five were in tumours with mutant p53 and three were in tumours with wild-type p53. Mdm2 overexpression was detected in 11 (50%) tumours. Of these, seven were in tumours with mutant p53 and four were in tumours with wild-type p53. Overall, 21 of the 22 tumours had p53 alterations either by mutation, deletion or inactivation by mdm2 or HPV. In this study, the overall incidence of p53 inactivation in recurrent head and neck cancer was very high at 95%. The main mechanism of inactivation was gene mutation or deletion which occurred in 15 of the 22 tumours studied. In addition, six of the seven tumours with wild-type p53 sequence had either HPV 16 DNA, overexpression of mdm2 or both which suggested that these tumours had p53 inactivation by these mechanisms. This high incidence of p53 dysfunction is one factor which could account for the poor response of these tumours to radiotherapy and chemotherapy. Therefore, new therapies for recurrent SCCHN which either act in a p53 independent pathway, or which restore p53 function may be beneficial in this disease.

Reduced MLH1 expression in breast tumors after primary chemotherapy predicts disease-free survival

PURPOSE

Loss of function or expression of the mismatch repair protein MLH1 and the tumor suppressor protein p53 have been implicated in acquired resistance to anticancer drugs. We have compared the expression of MLH1 and p53 in tumors from women with clinically node-positive breast cancer before and after primary (neoadjuvant) chemotherapy. Further, we have assessed the value of these markers as predictors of response to therapy by correlation with disease-free survival.

PATIENTS AND METHODS

Immunohistochemistry scores of MLH1 and p53 expression were made on 36 tru-cut prechemotherapy biopsies and 29 paired postchemotherapy tumor samples. The significance of the change in scores and their correlation with disease-free survival were evaluated by the Wilcoxon signed rank sum test and Cox proportional hazards regression analysis, respectively.

RESULTS

Primary chemotherapy results in a significant reduction in the percent of cells expressing MLH1 (P =.010). This change in MLH1 expression after chemotherapy is strongly associated with poor disease-free survival (P =.0025). Expression of p53 was not significantly altered by chemotherapy. Neither MLH1 nor p53 expression before chemotherapy predicted disease-free survival or tumor response to chemotherapy. Low MLH1 expression after chemotherapy was an independent predictor of poor disease-free survival on multivariate Cox analysis when considered with other clinicopathologic prognostic factors.

CONCLUSION

Tumor cells that have reduced MLH1 expression seem to have a survival advantage during combined chemotherapy of locally advanced breast cancers, which supports the hypothesis that loss of MLH1 has a role in drug resistance. MLH1 expression after chemotherapy is an independent predictive factor for poor disease-free survival and may, therefore, define a group of patients with drug-resistant breast cancer.

Progress in the treatment of ovarian cancer. Scottish Gynaecological Cancer Trials Group

With an overall response rate (ORR) of 30% in 315 evaluable patients in phase II trials, single-agent docetaxel has a level of activity in extensively pretreated ovarian cancer which is at least equivalent to and possibly superior to that of other new agents such as paclitaxel. In an initial series of 100 patients treated with the combination of docetaxel 75-85 mg/m2 plus cisplatin 75 mg/m2, the ORR was 66%. However, the combination was associated with a range of toxicities and only two-thirds of the patients were able to complete all six prescribed cycles. The combination of docetaxel with carboplatin has proved to be better tolerated while maintaining activity (ORR 67%). Based on these results, a randomized trial comparing docetaxel (75 mg/m2) in combination with carboplatin (AUC 5) versus paclitaxel (175 mg/m2) plus carboplatin (AUC 5) is underway. These results will provide important information on the role of docetaxel in the treatment of ovarian cancer.

Monocular and binocular depth discrimination thresholds

BACKGROUND

Measurement of stereoacuity at varying distances, by real or simulated depth stereoacuity tests, is helpful in the evaluation of patients with binocular imbalance or strabismus. Although the cue of binocular disparity underpins stereoacuity tests, there may be variable amounts of other binocular and monocular cues inherent in a stereoacuity test. In such circumstances, a combined monocular and binocular threshold of depth discrimination may be measured--stereoacuity conventionally referring to the situation where binocular disparity giving rise to retinal disparity is the only cue present. A child-friendly variable distance stereoacuity test (VDS) was developed, with a method for determining the binocular depth threshold from the combined monocular and binocular threshold of depth of discrimination (CT).

METHODS

Subjects with normal binocular function, reduced binocular function, and apparently absent binocularity were included. To measure the threshold of depth discrimination, subjects were required by means of a hand control to align two electronically controlled spheres at viewing distances of 1, 3, and 6m. Stereoacuity was also measured using the TNO, Frisby, and Titmus stereoacuity tests. BTs were calculated according to the function BT= arctan (1/tan alphaC - 1/tan alphaM)(-1), where alphaC and alphaM are the angles subtended at the nodal points by objects situated at the monocular threshold (alphaM) and the combined monocular-binocular threshold (alphaC) of discrimination.

RESULTS

In subjects with good binocularity, BTs were similar to their combined thresholds, whereas subjects with reduced and apparently absent binocularity had binocular thresholds 4 and 10 times higher than their combined thresholds (CT). The VDS binocular thresholds showed significantly higher correlation and agreement with the TNO test and the binocular thresholds of the Frisby and Titmus tests, than the corresponding combined thresholds (p = 0.0019).

CONCLUSION

The VDS was found to be an easy to use real depth (distance) stereoacuity test. The method described for calculating the BT provides one simple nonlinear solution for determining the respective contributions of binocular and monocular (MT) depth discrimination to the combined depth threshold.

Is small cell lung cancer the perfect target for anti-telomerase treatment?

Small cell lung cancer (SCLC) is common in men and women, has a very poor prognosis, and is therefore a major cause of premature mortality. As such, any prospects for improved therapy are of great significance. The promise of telomerase as a therapeutic target is now close to realization with extremely encouraging preclinical studies aimed at the RNA component (hTR) of telomerase. The rational integration of telomerase therapeutics into clinical trials will therefore require tumours to be well characterized for hTR expression. Despite the large number of cancer types now characterized for telomerase or telomerase component gene expression, only a handful of SCLC samples have been analysed. Given the major clinical problem with treating SCLC, we specifically set out to address the issue of hTR expression in neuroendocrine tumours. Our study covers 91 pulmonary neuroendocrine tumours (62 SCLC and 29 carcinoid tumours). We present data to show that upregulation of the RNA component of telomerase occurs in 98% of human SCLCs. Interestingly, the less aggressive carcinoid tumours of the lung had a significantly lower frequency of hTR expression (P < 0.01). Importantly, we compare hTR expression in this series to the well characterized biological targets p53 and BCL2, and show hTR to be expressed more frequently. Therapies directed at the RNA component of human telomerase are in active development and these data show SCLC to be a prime target for such therapies.

Prognostic factors in patients progressing after cisplatin-based chemotherapy for malignant non-seminomatous germ cell tumours

The aim of this study was to define prognostic parameters for survival in patients with malignant germ cell tumours progressing after platinum-based induction chemotherapy with or without surgery. A total of 164 progressing patients (testicular: 83%, extragonadal: 17%) were identified out of 795 patients treated with platinum-based induction chemotherapy for metastatic germ cell malignancy with or without surgery. 'Progressive disease' included patients who had progressed after a previous partial or complete remission as well as patients who failed primary therapy. Salvage chemotherapy consisted of 'conventional' platinum-based chemotherapy. Prognostic factors for survival were assessed by uni- and multivariate analyses. The resulting prognostic model was validated in an independent data set of 66 similar patients. For all 164 patients the median time from start of induction chemotherapy to progression was 10 months (range: 0-99). Thirty-eight (23%) patients relapsed after 2 years. The 5-year survival rate for all progressing patients was 30% (95% confidence interval 23-38%). In the univariate analysis the following factors most importantly predicted a poor prognosis: progression-free interval < 2 years: initial poor prognosis category (MRC criteria), < CR to induction chemotherapy, initial treatment early in the 1980s and treatment given at a 'small' centre. Three prognostic factors remained in the multivariate analysis: progression-free interval, response to induction treatment and the level of serum human chronic gonadotrophin (hCG) and alpha fetoprotein (AFP) at relapse. One hundred and twenty-four patients could be classified on the basis of these characteristics, Those patients with progression-free interval < 2 years, < CR to induction chemotherapy and high markers at relapse (AFP >100 kU l(-1) or hCG >100 IU l(-1)) formed a poor prognosis group of 30 patients, none of whom survived after 3 years. Patients with at most two of these three risk factors formed a good prognosis group of 94 patients (76%) with a 47% (37-56%) 5-year survival. Thirty-eight patients from the good prognosis group with a progression-free interval of >2 years had a 2-year survival of 74% (60-88%) and 5-year survival of 61%. These prognostic groups were validated in the independent data set, in which 5-year survival rates in the good and poor risk groups were 51% and 0% respectively. One-third of patients progressing during or after platinum-based induction chemotherapy for metastatic germ cell malignancy may be cured by repeated 'conventional' platinum-based chemotherapy. Good prognosis parameters are: progression-free interval of > 2 years, CR to induction treatment and normal or low serum markers at relapse (hCG < 100 IU l(-1) and AFP < 100 kU l(-1)). The results of high-dose salvage chemotherapy should be interpreted on the background of these prognostic factors.

Docetaxel and cisplatin in combination as first-line chemotherapy for advanced epithelial ovarian cancer. Scottish Gynaecological Cancer Trials Group

PURPOSE

A prospective, nonrandomized, multicenter, open feasibility study of cisplatin and docetaxel as first-line chemotherapy in International Federation of Gynecology and Obstetrics (FIGO) stage IC-IV epithelial ovarian cancer was conducted. The primary end point was the incidence of severe fluid retention that necessitated treatment withdrawal.

PATIENTS AND METHODS

Cisplatin and docetaxel were administered every 3 weeks for six planned cycles, with a 5-day prophylactic dexamethasone regimen (8 mg two times per day). One hundred patients (median age, 53 years; range, 24 to 71 years) received a total of 512 cycles of chemotherapy in two cohorts: cohort 1, 49 patients, 258 cycles (cisplatin 75 mg/m(2) and docetaxel 75 mg/m(2)); cohort 2, 51 patients, 254 cycles (cisplatin 75 mg/m(2) and docetaxel 85 mg/m(2)).

RESULTS

No patients were taken off study because of fluid retention. Sixty-six patients completed six cycles of protocol therapy; 16 stopped early because of toxicity (neurotoxicity in six patients, nephrotoxicity in three, neutropenia in two, and hypersensitivity, diarrhea and vomiting, skin rash, clinical deterioration, and patient's wishes in one patient each). Grade 3/4 neutropenia was observed in more than 75% of patients and seemed to be cumulative. Patients in cohort 2 had significantly more severe neutropenia and lethargy than those in cohort 1. In addition, there were five treatment-related deaths in cohort 2 (three neutropenia and two upper gastrointestinal hemorrhage). Neurotoxicity (mainly sensory, > grade 1) was observed in 23 patients. The overall clinical response rate was 69% (complete response, 38%; partial response, 31%); CA-125 response rate was 73%. Median progression-free survival for the group was 12 months.

CONCLUSION

Cisplatin and docetaxel can be administered at doses of 75 mg/m(2) and 75 mg/m(2), respectively, every 3 weeks, and the utility of this regimen is not limited by fluid retention. However, 33 of 100 patients were unable to complete the planned six cycles, which may explain, in part, the poor overall progression-free survival. Increasing the docetaxel dose to 85 mg/m(2) adds unacceptable hematologic toxicity and potential risks to the patient.

Impact of the treating institution on survival of patients with "poor-prognosis" metastatic nonseminoma. European Organization for Research and Treatment of Cancer Genito-Urinary Tract Cancer Collaborative Group and the Medical Research Council Testicular Cancer Working Party

BACKGROUND

Because metastatic nonseminomatous germ cell cancer is a rare but treatable cancer, we have explored whether there is an association between the experience of the treating institution with this disease and the long-term clinical outcome of the patients, particularly patients with a poor prognosis.

METHODS

We analyzed data on 380 patients treated in one of 49 institutions participating in the European Organization for Research and Treatment of Cancer/ Medical Research Council randomized trial of four cycles of bleomycin-etoposide-cisplatin followed by two cycles of etoposide-cisplatin versus three cycles of bleomycin-vincristine-cisplatin followed by three cycles of etoposide-ifosfamide-cisplatin-bleomycin, both treatment regimens given with or without filgrastim (granulocyte colony-stimulating factor). Institutions were divided into four groups based on the total number of patients entered in the trial. The groups were compared by use of the Cox proportional hazards model stratified for treatment with filgrastim and for patient prognosis as defined by the International Germ Cell Consensus Classification Group. With the use of this classification, only 65 % of the patients had a poor prognosis.

RESULTS

Patients treated in the 26 institutions that entered fewer than five patients into the trial had an overall survival that was statistically significantly worse (two-sided P = .010; hazard ratio = 1.85; 95% confidence interval = 1.16-3.03) than that of patients treated in the 23 institutions that entered five patients or more. Overall survival and failure-free survival were similar among institutions that entered at least five patients. The observed effect may be related to differences in adherence to the chemotherapy protocol and in the frequency and extent of surgery for residual masses, although only the differences in dose intensity achieved statistical significance.

CONCLUSIONS

Patients treated in institutions that entered fewer than five patients into the trial appeared to have poorer survival than those treated in institutions that entered a larger number of patients with "poor-prognosis" nonseminoma.

Advanced epithelial ovarian cancer: 1998 consensus statements

BACKGROUND

During an international workshop held in September 1998, a group of specialists in the field of ovarian cancer reached consensus on a number of issues with implications for standard practice and for research of advanced epithelial ovarian cancer.

METHODS

Five groups of experts considered several issues which included: biologic factors, prognostic factors, surgery, initial chemotherapy, second-line treatment, the use of CA 125, investigational drugs, intra-peritoneal treatment and high-dose chemotherapy. The group attempted to arrive at answers to questions such as: Are there prognostic factors, which help to identify patients who will not do well with current therapy? What is the current best therapy for advanced ovarian carcinoma? What directions should research take in advanced ovarian cancer? These issues were discussed in a plenary meeting.

RESULTS

One of the major conclusions drawn by the consensus committee was that in previously untreated advanced ovarian cancer, cisplatin plus paclitaxel has been shown to be superior to previous standard therapy with cisplatin plus cyclophosphamide (level I evidence). However, for many patients, carboplatin plus paclitaxel is a reasonable alternative because of toxicity and convenience considerations. Most participants felt that the benefits in terms of toxicity for the paclitaxel-carboplatin are such that its widespread adoption at this stage is justified. Until mature survival data are available a minority of investigators would recommend continued use of cisplatin plus paclitaxel, specifically for those patients with advanced disease with the best prognostic characteristics. For future clinical research in this area, new end points for randomised clinical trials, together with a new Trials Network, are proposed.

New non-cytotoxic approaches to ovarian cancer

Two recent examples of conventional cytotoxic drugs, taxoids and topo I inhibitors, are set to make a real impact in the treatment of ovarian cancer. However, further progress may depend on novel approaches, focusing on other targets. This review will concentrate on those approaches which have already led to the initiation of clinical trials: agents designed to circumvent cellular drug resistance, signal transduction inhibitors, new hormonal agents, matrix metalloproteinase inhibitors, immunotherapy, immunotoxins and radioconjugates, and intraperitoneal genetic therapy, including the use of replicating viruses. In some cases, early clinical data are encouraging, but ultimately combined treatment with conventional agents may make most impact.

Intergroup collaboration in ovarian cancer: a giant step forward

The rather slow evolution of so-called "optimal chemotherapy" for ovarian cancer is the result of suboptimal randomised clinical trials, not having the statistical power to identify truly superior regimens, and of the lack of systematic comparisons of new agents with relevant control arms. There is little doubt that we need international collaboration to move the field forward in a timely and coherent manner. European and transatlantic collaboration represents the beginning of the process and point to the success that can await us if the drive to work together remains strong. A similar organisation as for breast cancer (Breast International Group, BIG) needs to be established for ovarian cancer.

Basic research: how much do we know, and what are we likely to learn about ovarian cancer in the near future?

The scientific community, which studies ovarian cancer in the laboratory, is making progress in understanding many aspects of the disease. At present there is evidence that the cancer prone ovary has a preneoplastic phenotype. These genetic changes may constitute a surrogate intermediate end-point biomarker of cancer risk, which might be altered by preventive measures. Studies that aim at understanding the genetic basis of the disease are reviewed. Many of these studies use clinical ovarian cancer samples. To augment study of clinical specimens, an experimental system has been developed where malignancy is induced in the rat ovarian surface epithelium (ROSE). This system markedly facilitates examination of how genes fit into the ovarian cancer puzzle. The problem of drug resistance in ovarian cancer has received considerable attention. Although the functional changes responsible for resistance have been identified there has been little progress in identifying the actual genes capable of conferring the substantial resistance seen in cell lines.

Retinoids: present role and future potential

Vitamin A and its biologically active derivatives, retinal and retinoic acid (RA), together with a large repertoire of synthetic analogues are collectively referred to as retinoids. Naturally occurring retinoids regulate the growth and differentiation of a wide variety of cell types and play a crucial role in the physiology of vision and as morphogenic agents during embryonic development. Retinoids and their analogues have been evaluated as chemoprevention agents, and also in the management of acute promyelocytic leukaemia. Retinoids exert most of their effects by binding to specific receptors and modulating gene expression. The development of new active retinoids and the identification of two distinct families of retinoid receptors has led to an increased understanding of the cellular effects of activation of these receptors. In this article we review the use of retinoids in chemoprevention strategies, discuss the cellular consequences of activated retinoid receptors, and speculate on how our increasing understanding of retinoid-induced signalling pathways may contribute to future therapeutic strategies in the management of malignant disease.

In pursuit of excellence for patients with cancer: the Scottish Cancer Therapy Network model

The Scottish Cancer Therapy Network (SCTN) was created against a background of rising concerns about perceived variation in the quality of care available to patients with cancer. SCTN has established itself as a major organization with the necessary recognition and infrastructure to provide leadership, support and impetus in the field of clinical guidelines, clinical audit and clinical trials of cancer therapy in Scotland. Since being formed in 1993, SCTN has been instrumental in the development of three evidence-based, clinical guidelines and in the completion of detailed, national, retrospective audits of the treatment of five major tumour sites. The infrastructure has been used successfully to support and encourage trial participation. Challenges for the future are a re-orientation towards prospective audit, widening the constituency and sense of ownership of SCTN as a resource for practising clinicians, and further increasing recruitment into clinical trials.

Phase I/pharmacokinetic study of the topoisomerase I inhibitor GG211 administered as a 21-day continuous infusion

BACKGROUND

Preclinical results support a prolonged schedule of administration for topoisomerase I inhibitors, and we have previously demonstrated the safety and activity of the novel water-soluble topoisomerase I inhibitor GG211 when given as a 72-hour continuous infusion to cancer patients.

PATIENTS AND METHODS

In a three-center international phase I trial, 38 patients received GG211 doses from 0.3 to 0.5 mg/m2/day by continuous intravenous infusions for seven, 14, and 21 days. Patients' median performance status was 1; nearly half had colorectal cancer, and 35 patients had prior chemotherapy.

RESULTS

The first patient cohort received 0.3 mg/m2/day for seven days with no significant toxicities. Subsequent cohorts received continuous infusions for 14 and 21 days at this dose level with only mild myelosuppression noted. Dose-escalation on the 21-day schedule was then performed. No dose-limiting toxicity occurred at the 0.4 mg/m2/day dose level. Thrombocytopenia was dose-limiting with 0.5 mg/m2/day dosing but was not cumulative. Other grade 3 4 toxicities included neutropenia, nausea, vomiting, diarrhea, and fatigue. Partial responses occurred with 21-day infusion in two patients with breast and ovarian cancer at the 0.3 and 0.4 mg/m2/day dose levels, respectively. Mean GG211 lactone Css ranged from 0.17 to 0.64 ng/ml.

CONCLUSION

The maximum tolerated dose of GG211 administered as a 21-day continuous infusion is 0.4 mg/m2/day with antitumor activity noted at tolerable doses.

Perspective: cancer care and the new biology

Over the past 25 years, measurable--albeit relatively modest--improvements in the outcome of treatment for patients with cancer have taken place. During a similar time period, there has been an explosion of information on the molecular biology and genetic basis of cancer, with the evolution of a remarkable array of new and powerful laboratory tools. The advances made in cancer care owe little to these developments in the laboratory. Looking forward, however, the opportunity now exists for the new knowledge to be harnessed, through a proper partnership of laboratory and clinical scientists, to provide significant further improvements in results. These should occur through developments in prevention, early diagnosis, and particularly in new forms of therapy. This will require a shift in emphasis on the part of all concerned, and there is already evidence that this is beginning to happen.

Phase I clinical and pharmacokinetic study of PK1 [N-(2-hydroxypropyl)methacrylamide copolymer doxorubicin]: first member of a new class of chemotherapeutic agents-drug-polymer conjugates. Cancer Research Campaign Phase I/II Committee

PK1 comprises doxorubicin covalently bound to N-(2-hydroxypropyl)methacrylamide copolymer by a peptidyl linker. Following cellular uptake via pinocytosis, the linker is cleaved by lysosomal enzymes, allowing intratumoral drug release. Radically altered plasma and tumor pharmacokinetics, compared to free doxorubicin, and significant activity in animal tumors have been demonstrated preclinically. We aimed to determine the maximum tolerated dose, toxicity profile, and pharmacokinetics of PK1 as an i.v. infusion every 3 weeks to patients with refractory or resistant cancers. Altogether, 100 cycles were administered (range, 20-320 mg/m2 doxorubicin-equivalent) to 36 patients (20 males and 16 females) with a mean age of 58.3 years (age range, 34-72 years). The maximum tolerated dose was 320 mg/m2, and the dose-limiting toxicities were febrile neutropenia and mucositis. No congestive cardiac failure was seen despite individual cumulative doses up to 1680 mg/m2. Other anthracycline-like toxicities were attenuated. Pharmacokinetically, PK1 has a distribution t(1/2) of 1.8 h and an elimination t(1/2) averaging 93 h. 131I-labeled PK1 imaging suggests PK1 is taken up by some tumors. Responses (two partial and two minor responses) were seen in four patients with NSCLC, colorectal cancer, and anthracycline-resistant breast cancer. PK1 demonstrated antitumor activity in refractory cancers, no polymer-related toxicity, and proof of principle that polymer-drug conjugation decreases doxorubicin dose-limiting toxicities. The recommended Phase II dose is 280 mg/m2 every 3 weeks. Studies are planned in colorectal, NSCLC, and breast cancer patients.